Change bilinear interpolation to lanczos resampling,

and update related unit tests and selenium reference img.
Review URL: http://codereview.chromium.org/159180

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@21299 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 672 insertions, 599 deletions

diff --git a/o3d/DEPS b/o3d/DEPS
index 306a956..04f0d55 100644
--- a/o3d/DEPS
+++ b/o3d/DEPS
@@ -2,7 +2,7 @@ vars = {
   "chromium_trunk":
     "http://src.chromium.org/svn/trunk",
   "nixysa_rev": "28",
-  "o3d_code_rev": "100",
+  "o3d_code_rev": "101",
 }
 
 deps = {
diff --git a/o3d/DEPS_gyp b/o3d/DEPS_gyp
index f7b2829..2ea2108 100644
--- a/o3d/DEPS_gyp
+++ b/o3d/DEPS_gyp
@@ -3,7 +3,7 @@ vars = {
     "http://src.chromium.org/svn/trunk",
   "nixysa_rev": "28",
   "chromium_rev": "19644",
-  "o3d_code_rev": "97",
+  "o3d_code_rev": "101",
 }
 
 deps = {
diff --git a/o3d/core/cross/bitmap.cc b/o3d/core/cross/bitmap.cc
index 98863cf..6487fbd 100644
--- a/o3d/core/cross/bitmap.cc
+++ b/o3d/core/cross/bitmap.cc
@@ -54,6 +54,19 @@ using file_util::GetFileSize;
 
 namespace {
 static const double kEpsilon = 0.0001;
+static const double kPi = 3.14159265358979;
+static const int kFilterSize = 3;
+
+// utility function, round double numbers into 0 to 255 integers.
+uint8 Safe8Round(double f) {
+  f += 0.5;
+  if (f < 0.0) {
+    return 0;
+  } else if (!(f < 255.0)) {
+    return 255;
+  }
+  return static_cast<uint8>(f);
+}
 }  // anonymous namespace.
 
 namespace o3d {
@@ -333,117 +346,147 @@ void Bitmap::DrawImage(Bitmap* src_img,
   // crop part of image from src img, scale it in
   // bilinear interpolation fashion, and paste it
   // on dst img.
-  BilinearInterpolateScale(src_img_data, src_x, src_y,
-                           src_width, src_height,
-                           src_img->width_, src_img->height_,
-                           dst_img_data, dst_x, dst_y,
-                           dst_width, dst_height,
-                           width_, height_, components);
+  LanczosScale(src_img_data, src_x, src_y,
+               src_width, src_height,
+               src_img->width_, src_img->height_,
+               dst_img_data, dst_x, dst_y,
+               dst_width, dst_height,
+               width_, height_, components);
+}
+
+void Bitmap::LanczosScale(const uint8* src,
+                          int src_x, int src_y,
+                          int src_width, int src_height,
+                          int src_img_width, int src_img_height,
+                          uint8* dest,
+                          int dest_x, int dest_y,
+                          int dest_width, int dest_height,
+                          int dest_img_width, int dest_img_height,
+                          int components) {
+  // Scale the image horizontally to a temp buffer.
+  int temp_img_width = abs(dest_width);
+  int temp_img_height = abs(src_height);
+  int temp_width = dest_width;
+  int temp_height = src_height;
+  int temp_x = 0, temp_y = 0;
+  if (temp_width < 0)
+    temp_x = abs(temp_width) - 1;
+  if (temp_height < 0)
+    temp_y = abs(temp_height) - 1;
+
+  scoped_array<uint8> temp(new uint8[temp_img_width *
+                                     temp_img_height * components]);
+
+  LanczosResize1D(src, src_x, src_y, src_width, src_height,
+                  src_img_width, src_img_height,
+                  temp.get(), temp_x, temp_y, temp_width,
+                  temp_img_width, temp_img_height, true, components);
+
+  // Scale the temp buffer vertically to get the final result.
+  LanczosResize1D(temp.get(), temp_x, temp_y, temp_height, temp_width,
+                  temp_img_width, temp_img_height,
+                  dest, dest_x, dest_y, dest_height,
+                  dest_img_width, dest_img_height, false, components);
 }
 
-// static utility function used by DrawImage in bitmap and textures.
-// in this function, positions are converted to 4th-quadrant, which
-// means origin locates left-up corner.
-void Bitmap::BilinearInterpolateScale(const uint8* src_img_data,
-                                      int src_x, int src_y,
-                                      int src_width, int src_height,
-                                      int src_img_width, int src_img_height,
-                                      uint8* dest_img_data,
-                                      int dest_x, int dest_y,
-                                      int dest_width, int dest_height,
-                                      int dest_img_width, int dest_img_height,
-                                      int components) {
-  for (int i = 0; i < std::abs(dest_width); i++) {
-    // x is the iterator of dest_width in dest_img.
-    // change x to negative if dest_width is negative.
+void Bitmap::LanczosResize1D(const uint8* src, int src_x, int src_y,
+                             int width, int height,
+                             int src_bmp_width, int src_bmp_height,
+                             uint8* out, int dest_x, int dest_y,
+                             int nwidth,
+                             int dest_bmp_width, int dest_bmp_height,
+                             bool isWidth, int components) {
+  // calculate scale factor and init the weight array for lanczos filter.
+  float scale = fabs(static_cast<float>(width) / nwidth);
+  float support = kFilterSize * scale;
+  scoped_array<float> weight(new float[static_cast<int>(support * 2) + 4]);
+  // we assume width is the dimension we are scaling, and height stays
+  // the same.
+  for (int i = 0; i < abs(nwidth); ++i) {
+    // center is the corresponding coordinate of i in original img.
+    float center = (i + 0.5) * scale;
+    // boundary of weight array in original img.
+    int xmin = static_cast<int>(floor(center - support));
+    if (xmin < 0) xmin = 0;
+    int xmax = static_cast<int>(ceil(center + support));
+    if (xmax >= abs(width)) xmax = abs(width) - 1;
+
+    // fill up weight array by lanczos filter.
+    float wsum = 0.0;
+    for (int ox = xmin; ox <= xmax; ++ox) {
+      float wtemp;
+      float dx = ox + 0.5 - center;
+      // lanczos filter
+      if (dx <= -kFilterSize || dx >= kFilterSize) {
+        wtemp = 0.0;
+      } else if (dx == 0.0) {
+        wtemp = 1.0;
+      } else {
+        wtemp = kFilterSize * sin(kPi * dx) * sin(kPi / kFilterSize * dx) /
+                (kPi * kPi * dx * dx);
+      }
+
+      weight[ox - xmin] = wtemp;
+      wsum += wtemp;
+    }
+    int wcount = xmax - xmin + 1;
+
+    // Normalize the weights.
+    if (fabs(wsum) > kEpsilon) {
+      for (int k = 0; k < wcount; ++k) {
+        weight[k] /= wsum;
+      }
+    }
+    // Now that we've computed the filter weights for this x-position
+    // of the image, we can apply that filter to all pixels in that
+    // column.
+    // calculate coordinate in new img.
     int x = i;
-    if (dest_width < 0)
-      x = -i;
-
-    // calculate corresponding coordinate in src_img.
-    double base_x = i * (std::abs(src_width) - 1) /
-                    static_cast<double>(std::abs(dest_width) - 1);
-    // base_floor_x is the iterator of src_width in src_img.
-    // change base_x to negative if src_width is negative.
-    if (src_width < 0)
-      base_x = -base_x;
-    int base_floor_x = static_cast<int>(std::floor(base_x));
-
-    for (int j = 0; j < std::abs(dest_height); j++) {
-      // y is the iterator of dest_height in dest_img.
-      // change y to negative if dest_height is negative.
-      int y = j;
-      if (dest_height < 0)
-        y = -j;
-
-      // calculate coresponding coordinate in src_img.
-      double base_y = j * (std::abs(src_height) - 1) /
-                      static_cast<double>(std::abs(dest_height) - 1);
-      // change base_y to negative if src_height is negative.
-      if (src_height < 0)
-        base_y = -base_y;
-      int base_floor_y = static_cast<int>(std::floor(base_y));
-
-      for (int c = 0; c < components; c++) {
-        // if base_x and base_y are integers, which means this point
-        // exists in src_img, just copy the original values.
-        if (base_x - base_floor_x < kEpsilon &&
-            base_y - base_floor_y < kEpsilon) {
-          dest_img_data[((dest_img_height - (y + dest_y) - 1) *
-                        dest_img_width + dest_x + x) * components + c] =
-          src_img_data[((src_img_height - (base_floor_y + src_y) - 1) *
-                       src_img_width + src_x + base_floor_x) * components + c];
-          continue;
+    if (nwidth < 0)
+      x = -1 * x;
+    // lower bound of coordinate in original img.
+    if (width < 0)
+      xmin = -1 * xmin;
+    for (int j = 0; j < abs(height); ++j) {
+      // coordinate in height, same in src and dest img.
+      int base_y = j;
+      if (height < 0)
+        base_y = -1 * base_y;
+      // TODO(yux): fix the vertical flip problem and merge this if-else
+      // statement coz at that time, there would be no need to check
+      // which measure we are scaling.
+      if (isWidth) {
+        const uint8* inrow = src + ((src_bmp_height - (src_y + base_y) - 1) *
+                             src_bmp_width + src_x + xmin) * components;
+        uint8* outpix = out + ((dest_bmp_height - (dest_y + base_y) - 1) *
+                        dest_bmp_width + dest_x + x) * components;
+        int step = components;
+        if (width < 0)
+          step = -1 * step;
+        for (int b = 0; b < components; ++b) {
+          float sum = 0.0;
+          for (int k = 0, xk = b; k < wcount; ++k, xk += step)
+            sum += weight[k] * inrow[xk];
+
+          outpix[b] = Safe8Round(sum);
+        }
+      } else {
+        const uint8* inrow = src + (src_x + base_y + (src_bmp_height -
+                             (src_y + xmin) - 1) * src_bmp_width) *
+                             components;
+        uint8* outpix = out + (dest_x + base_y + (dest_bmp_height -
+                        (dest_y + x) - 1) * dest_bmp_width) * components;
+
+        int step = src_bmp_width * components;
+        if (width < 0)
+          step = -1 * step;
+        for (int b = 0; b < components; ++b) {
+          float sum = 0.0;
+          for (int k = 0, xk = b; k < wcount; ++k, xk -= step)
+            sum += weight[k] * inrow[xk];
+
+          outpix[b] = Safe8Round(sum);
         }
-
-        // get four nearest neighbors of point (base_x, base_y) from src img.
-        uint8 src_neighbor_11, src_neighbor_21,
-              src_neighbor_12, src_neighbor_22;
-        src_neighbor_11 = src_img_data[((src_img_height - (base_floor_y +
-                                       src_y) - 1) * src_img_width + src_x +
-                                       base_floor_x) * components + c];
-        // if base_x exists in src img. set src_neighbor_21 to src_neighbor_11
-        // so the interpolation result would remain src_neighbor_11.
-        if (base_x - base_floor_x < kEpsilon)
-          src_neighbor_21 = src_neighbor_11;
-        else
-          src_neighbor_21 = src_img_data[((src_img_height - (base_floor_y +
-                                         src_y) - 1) * src_img_width + src_x +
-                                         base_floor_x + 1) * components + c];
-        // if base_y exists in src img. set src_neighbor_12 to src_neighbor_11
-        // so the interpolation result would remain src_neighbor_11.
-        if (base_y - base_floor_y < kEpsilon)
-          src_neighbor_12 = src_neighbor_11;
-        else
-          src_neighbor_12 = src_img_data[((src_img_height - (base_floor_y +
-                                         src_y) - 2) * src_img_width + src_x +
-                                         base_floor_x) * components + c];
-
-        if (base_x - base_floor_x < kEpsilon)
-          src_neighbor_22 = src_neighbor_21;
-        else if (base_y - base_floor_y < kEpsilon)
-          src_neighbor_22 = src_neighbor_12;
-        else
-          src_neighbor_22 = src_img_data[((src_img_height - (base_floor_y +
-                                         src_y) - 2) * src_img_width + src_x +
-                                         base_floor_x + 1) * components + c];
-
-        // calculate interpolated value.
-        double interpolatedValue = (1 - (base_y - base_floor_y)) *
-                                   ((base_x - base_floor_x) *
-                                   src_neighbor_21 +
-                                   (1 - (base_x - base_floor_x)) *
-                                   src_neighbor_11) +
-                                   (base_y - base_floor_y) *
-                                   ((base_x - base_floor_x) *
-                                   src_neighbor_22 +
-                                   (1 - (base_x - base_floor_x)) *
-                                   src_neighbor_12);
-
-        // assign the nearest integer of interpolatedValue to dest_img_data.
-        dest_img_data[((dest_img_height - (y + dest_y) - 1) * dest_img_width +
-                        dest_x + x) * components + c] =
-        static_cast<uint8>(interpolatedValue + 0.5);
       }
     }
   }
diff --git a/o3d/core/cross/bitmap.h b/o3d/core/cross/bitmap.h
index 8100b86..bebe6c6 100644
--- a/o3d/core/cross/bitmap.h
+++ b/o3d/core/cross/bitmap.h
@@ -1,439 +1,469 @@
-/*
- * Copyright 2009, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-
-// This file contains the declaration of Bitmap helper class that can load
-// raw 24- and 32-bit bitmaps from popular image formats. The Bitmap class
-// also interprets the file format to record the correct OpenGL buffer format.
-//
-// Trying to keep this class independent from the OpenGL API in case they
-// need retargeting later on.
-
-#ifndef O3D_CORE_CROSS_BITMAP_H_
-#define O3D_CORE_CROSS_BITMAP_H_
-
-#include <stdlib.h>
-
-#include "base/cross/bits.h"
-#include "core/cross/types.h"
-#include "core/cross/texture.h"
-
-class FilePath;
-
-namespace o3d {
-
-class MemoryReadStream;
-class RawData;
-class Pack;
-
-// Bitmap provides an API for basic image operations on bitmap images,
-// including scale and crop. The contents of bitmap can be created from
-// a RawData object via LoadFromRawData(), and also can be transfered
-// to mip of a Texure2D or a specific face of TextureCUBE via methods
-// in Texture.
-
-class Bitmap : public ParamObject {
- public:
-  typedef SmartPointer<Bitmap> Ref;
-
-  explicit Bitmap(ServiceLocator* service_locator);
-  virtual ~Bitmap() {}
-
-  // We will fail to load images that are bigger than 4kx4k to avoid security
-  // risks. GPUs don't usually support bigger sizes anyway.
-  // The biggest bitmap buffer size with these dimensions is:
-  // 4k x 4k x 4xsizeof(float) x6 x4/3 (x6 for cube maps, x4/3 for mipmaps)
-  // That makes 2GB, representable in an unsigned int, so we will avoid wraps.
-  static const unsigned int kMaxImageDimension = 4096;
-  enum ImageFileType {
-    UNKNOWN,
-    TGA,
-    JPEG,
-    PNG,
-    DDS,
-  };
-
-  static bool CheckImageDimensions(unsigned int width, unsigned int height) {
-    return width > 0 && height > 0 &&
-        width <= kMaxImageDimension && height < kMaxImageDimension;
-  }
-
-  // Creates a copy of a bitmap, copying the pixels as well.
-  // Parameters:
-  //   source: the source bitmap.
-  void CopyDeepFrom(const Bitmap &source) {
-    Allocate(source.format_, source.width_, source.height_,
-             source.num_mipmaps_, source.is_cubemap_);
-    memcpy(image_data(), source.image_data(), GetTotalSize());
-  }
-
-  // Sets the bitmap parameters from another bitmap, stealing the pixel buffer
-  // from the source bitmap.
-  // Parameters:
-  //   source: the source bitmap.
-  void SetFrom(Bitmap *source) {
-    image_data_.reset();
-    format_ = source->format_;
-    width_ = source->width_;
-    height_ = source->height_;
-    num_mipmaps_ = source->num_mipmaps_;
-    is_cubemap_ = source->is_cubemap_;
-    image_data_.swap(source->image_data_);
-  }
-
-  // Allocates an uninitialized bitmap with specified parameters.
-  // Parameters:
-  //   format: the format of the pixels.
-  //   width: the width of the base image.
-  //   height: the height of the base image.
-  //   num_mipmaps: the number of mip-maps.
-  //   cube_map: true if creating a cube map.
-  void Allocate(Texture::Format format,
-                unsigned int width,
-                unsigned int height,
-                unsigned int num_mipmaps,
-                bool cube_map);
-
-  // Allocates a bitmap with initialized parameters.
-  // data is zero-initialized
-  void AllocateData() {
-    image_data_.reset(new unsigned char[GetTotalSize()]);
-    memset(image_data_.get(), 0, GetTotalSize());
-  }
-
-  // Frees the data owned by the bitmap.
-  void FreeData() {
-    image_data_.reset(NULL);
-  }
-
-  // Gets the total size of the bitmap data, counting all faces and mip levels.
-  unsigned int GetTotalSize() {
-    return (is_cubemap_ ? 6 : 1) *
-        GetMipChainSize(width_, height_, format_, num_mipmaps_);
-  }
-
-  // Computes the number of bytes of a texture pixel buffer.
-  static unsigned int GetBufferSize(unsigned int width,
-                                    unsigned int height,
-                                    Texture::Format format);
-
-  // Gets the image data for a given mip-map level and cube map face.
-  // Parameters:
-  //   level: mip level to get.
-  //   face: face of cube to get. This parameter is ignored if
-  //       this bitmap is not a cube map.
-  unsigned char *GetMipData(unsigned int level,
-                            TextureCUBE::CubeFace face) const;
-
-  unsigned char *image_data() const { return image_data_.get(); }
-  Texture::Format format() const { return format_; }
-  unsigned int width() const { return width_; }
-  unsigned int height() const { return height_; }
-  unsigned int num_mipmaps() const { return num_mipmaps_; }
-  bool is_cubemap() const { return is_cubemap_; }
-
-  // Returns whether or not the dimensions of the bitmap are power-of-two.
-  bool IsPOT() const {
-    return ((width_ & (width_ - 1)) == 0) && ((height_ & (height_ - 1)) == 0);
-  }
-
-  void set_format(Texture::Format format) { format_ = format; }
-  void set_width(unsigned int n) { width_ = n; }
-  void set_height(unsigned int n) { height_ = n; }
-  void set_num_mipmaps(unsigned int n) { num_mipmaps_ = n; }
-  void set_is_cubemap(bool is_cubemap) { is_cubemap_ = is_cubemap; }
-
-  // Loads a bitmap from a file.
-  // Parameters:
-  //   filename: the name of the file to load.
-  //   file_type: the type of file to load. If UNKNOWN, the file type will be
-  //              determined from the filename extension, and if it is not a
-  //              known extension, all the loaders will be tried.
-  //   generate_mipmaps: whether or not to generate all the mip-map levels.
-  bool LoadFromFile(const FilePath &filepath,
-                    ImageFileType file_type,
-                    bool generate_mipmaps);
-
-  // Loads a bitmap from a RawData object.
-  // Parameters:
-  //   raw_data: contains the bitmap data in one of the known formats
-  //   file_type: the format of the bitmap data. If UNKNOWN, the file type
-  //              will be determined from the extension from raw_data's uri
-  //              and if it is not a known extension, all the loaders will
-  //              be tried.
-  //   generate_mipmaps: whether or not to generate all the mip-map levels.
-  bool LoadFromRawData(RawData *raw_data,
-                       ImageFileType file_type,
-                       bool generate_mipmaps);
-
-  // Loads a bitmap from a MemoryReadStream.
-  // Parameters:
-  //   stream: a stream for the bitmap data in one of the known formats
-  //   filename: a filename (or uri) of the original bitmap data
-  //             (may be an empty string)
-  //   file_type: the format of the bitmap data. If UNKNOWN, the file type
-  //              will be determined from the extension of |filename|
-  //              and if it is not a known extension, all the loaders
-  //              will be tried.
-  //   generate_mipmaps: whether or not to generate all the mip-map levels.
-  bool LoadFromStream(MemoryReadStream *stream,
-                      const String &filename,
-                      ImageFileType file_type,
-                      bool generate_mipmaps);
-
-  bool LoadFromPNGStream(MemoryReadStream *stream,
-                         const String &filename,
-                         bool generate_mipmaps);
-
-  bool LoadFromTGAStream(MemoryReadStream *stream,
-                         const String &filename,
-                         bool generate_mipmaps);
-
-  bool LoadFromDDSStream(MemoryReadStream *stream,
-                         const String &filename,
-                         bool generate_mipmaps);
-
-  bool LoadFromJPEGStream(MemoryReadStream *stream,
-                          const String &filename,
-                          bool generate_mipmaps);
-
-  // Saves to a PNG file. The image must be of the ARGB8 format, be a 2D image
-  // with no mip-maps (only the base level).
-  // Parameters:
-  //   filename: the name of the file to into.
-  // Returns:
-  //   true if successful.
-  bool SaveToPNGFile(const char* filename);
-
-  // Checks that the alpha channel for the entire bitmap is 1.0
-  bool CheckAlphaIsOne() const;
-
-  // Copy pixels from source bitmap. Scales if the width and height of source
-  // and dest do not match.
-  // Parameters:
-  //   source_img: source bitmap which would be drawn.
-  //   source_x: x-coordinate of the starting pixel in the source image.
-  //   source_x: y-coordinate of the starting pixel in the source image.
-  //   source_width: width of the source image to draw.
-  //   source_height: Height of the source image to draw.
-  //   dest_x: x-coordinate of the starting pixel in the dest image.
-  //   dest_y: y-coordinate of the starting pixel in the dest image.
-  //   dest_width: width of the dest image to draw.
-  //   dest_height: height of the dest image to draw.
-  void DrawImage(Bitmap* source_img, int source_x, int source_y,
-                 int source_width, int source_height,
-                 int dest_x, int dest_y,
-                 int dest_width, int dest_height);
-
-  // Crop part of an image from src, scale it to an arbitrary size
-  // and paste in dest image. Utility function for all DrawImage
-  // function in bitmap and textures. Scale operation is based on
-  // bilinear interpolation.
-  // Note: this doesn't work for DXTC, or floating-point images.
-  //
-  // Parameters:
-  //   src: source image which would be copied from.
-  //   src_x: x-coordinate of the starting pixel in the src image.
-  //   src_y: y-coordinate of the starting pixel in the src image.
-  //   src_width: width of the part in src image to be croped.
-  //   src_height: height of the part in src image to be croped.
-  //   src_img_width: width of the src image.
-  //   src_img_height: height of the src image.
-  //   dest: dest image which would be copied to.
-  //   dest_x: x-coordinate of the starting pixel in the dest image.
-  //   dest_y: y-coordinate of the starting pixel in the dest image.
-  //   dest_width: width of the part in dest image to be pasted to.
-  //   dest_height: height of the part in dest image to be pasted to.
-  //   dest_img_width: width of the dest image.
-  //   dest_img_height: height of the src image.
-  //   component: size of each pixel in terms of array element.
-  // Returns:
-  //   true if crop and scale succeeds.
-  static void BilinearInterpolateScale(const uint8* src,
-                                       int src_x, int src_y,
-                                       int src_width, int src_height,
-                                       int src_img_width, int src_img_height,
-                                       uint8* dest,
-                                       int dest_x, int dest_y,
-                                       int dest_width, int dest_height,
-                                       int dest_img_width, int dest_img_height,
-                                       int component);
-
-  // Detects the type of image file based on the filename.
-  static ImageFileType GetFileTypeFromFilename(const char *filename);
-  // Detects the type of image file based on the mime-type.
-  static ImageFileType GetFileTypeFromMimeType(const char *mime_type);
-
-  // Adds filler alpha byte (0xff) after every pixel. Assumes buffer was
-  // allocated with enough storage)
-  // can convert RGB -> RGBA, BGR -> BGRA, etc.
-  static void XYZToXYZA(unsigned char *image_data, int pixel_count);
-
-  // Swaps Red and Blue components in the image.
-  static void RGBAToBGRA(unsigned char *image_data, int pixel_count);
-
-  // Gets the number of mip-maps required for a full chain starting at
-  // width x height.
-  static unsigned int GetMipMapCount(unsigned int width, unsigned int height) {
-    return 1 + base::bits::Log2Floor(std::max(width, height));
-  }
-
-  // Gets the smallest power-of-two value that is at least as high as
-  // dimension. This is the POT dimension used in ScaleUpToPOT.
-  static unsigned int GetPOTSize(unsigned int dimension) {
-    return 1 << base::bits::Log2Ceiling(dimension);
-  }
-
-  // Gets the size of the buffer containing a mip-map chain, given its base
-  // width, height, format and number of mip-map levels.
-  static unsigned int GetMipChainSize(unsigned int base_width,
-                                      unsigned int base_height,
-                                      Texture::Format format,
-                                      unsigned int num_mipmaps);
-
-  // Generates mip-map levels for a single image, using the data from the base
-  // level.
-  // NOTE: this doesn't work for DXTC, or floating-point images.
-  //
-  // Parameters:
-  //   base_width: the width of the base image.
-  //   base_height: the height of the base image.
-  //   format: the format of the data.
-  //   num_mipmaps: the number of mipmaps to generate.
-  //   data: the data containing the base image, and enough space for the
-  //   mip-maps.
-  static bool GenerateMipmaps(unsigned int base_width,
-                              unsigned int base_height,
-                              Texture::Format format,
-                              unsigned int num_mipmaps,
-                              unsigned char *data);
-
-  // Scales an image up to power-of-two textures, using point filtering.
-  // NOTE: this doesn't work for DXTC, or floating-point images.
-  //
-  // Parameters:
-  //   width: the non-power-of-two width of the original image.
-  //   height: the non-power-of-two height of the original image.
-  //   format: the format of the data.
-  //   src: the data containing the source data of the original image.
-  //   dst: a buffer with enough space for the power-of-two version. Pixels are
-  //   written from the end to the beginning so dst can be the same buffer as
-  //   src.
-  static bool ScaleUpToPOT(unsigned int width,
-                           unsigned int height,
-                           Texture::Format format,
-                           const unsigned char *src,
-                           unsigned char *dst);
-
-  // Scales an image to an arbitrary size, using point filtering.
-  // NOTE: this doesn't work for DXTC, or floating-point images.
-  //
-  // Parameters:
-  //   src_width: the width of the original image.
-  //   src_height: the height of the original image.
-  //   format: the format of the data.
-  //   src: the data containing the source data of the original image.
-  //   dst_width: the width of the target image.
-  //   dst_height: the height of the target image.
-  //   dst: a buffer with enough space for the target version. Pixels are
-  //   written from the end to the beginning so dst can be the same buffer as
-  //   src if the transformation is an upscaling.
-  static bool Scale(unsigned int src_width,
-                    unsigned int src_height,
-                    Texture::Format format,
-                    const unsigned char *src,
-                    unsigned int dst_width,
-                    unsigned int dst_height,
-                    unsigned char *dst);
-
-  // adjust start points and boundaries when using DrawImage data
-  // in bitmap and textures.
-  // Parameters:
-  //   src_x: x-coordinate of the starting pixel in the source image.
-  //   src_y: y-coordinate of the starting pixel in the source image.
-  //   src_width: width of the source image to draw.
-  //   src_height: height of the source image to draw.
-  //   src_bmp_width: original width of source bitmap.
-  //   src_bmp_height: original height of source bitmap.
-  //   dest_x: x-coordinate of the starting pixel in the dest image.
-  //   dest_y: y-coordinate of the starting pixel in the dest image.
-  //   dest_width: width of the dest image to draw.
-  //   dest_height: height of the dest image to draw.
-  //   dest_bmp_width: original width of dest bitmap.
-  //   dest_bmp_height: original height of dest bitmap.
-  // Returns:
-  //   false if src or dest rectangle is out of boundaries.
-  static bool AdjustDrawImageBoundary(int* src_x, int* src_y,
-                                      int* src_width, int* src_height,
-                                      int src_bmp_width, int src_bmp_height,
-                                      int* dest_x, int* dest_y,
-                                      int* dest_width, int* dest_height,
-                                      int dest_bmp_width, int dest_bmp_height);
-
- private:
-  friend class IClassManager;
-  static ObjectBase::Ref Create(ServiceLocator* service_locator);
-
-  // pointer to the raw bitmap data
-  scoped_array<uint8> image_data_;
-  // format of the texture this is meant to represent.
-  Texture::Format format_;
-  // width of the bitmap in pixels.
-  int width_;
-  // height of the bitmap in pixels.
-  int height_;
-  // number of mipmap levels in this texture.
-  unsigned int num_mipmaps_;
-  // is this cube-map data
-  bool is_cubemap_;
-
-  // utility function used in AdjustDrawImageBoundary.
-  // It adjusts start point and related measures
-  // for a specific dimension.
-  // Parameter:
-  //   src_a: the coordinate which is negative.
-  //   dest_a: same coordinate in the other image.
-  //   src_length: length measure of source image to draw.
-  //   dest_length: length measure of dest image to draw.
-  //   src_bmp_length: length measure of src image.
-  // Returns:
-  //   true if adjust is successful.
-  static bool AdjustDrawImageBoundHelper(int* src_a, int* dest_a,
-                                         int* src_length, int* dest_length,
-                                         int src_bmp_length);
-
-  O3D_DECL_CLASS(Bitmap, ParamObject);
-  DISALLOW_COPY_AND_ASSIGN(Bitmap);
-};
-
-}  // namespace o3d
-
-#endif  // O3D_CORE_CROSS_BITMAP_H_
+/*

+ * Copyright 2009, Google Inc.

+ * All rights reserved.

+ *

+ * Redistribution and use in source and binary forms, with or without

+ * modification, are permitted provided that the following conditions are

+ * met:

+ *

+ *     * Redistributions of source code must retain the above copyright

+ * notice, this list of conditions and the following disclaimer.

+ *     * Redistributions in binary form must reproduce the above

+ * copyright notice, this list of conditions and the following disclaimer

+ * in the documentation and/or other materials provided with the

+ * distribution.

+ *     * Neither the name of Google Inc. nor the names of its

+ * contributors may be used to endorse or promote products derived from

+ * this software without specific prior written permission.

+ *

+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

+ */

+

+

+// This file contains the declaration of Bitmap helper class that can load

+// raw 24- and 32-bit bitmaps from popular image formats. The Bitmap class

+// also interprets the file format to record the correct OpenGL buffer format.

+//

+// Trying to keep this class independent from the OpenGL API in case they

+// need retargeting later on.

+

+#ifndef O3D_CORE_CROSS_BITMAP_H_

+#define O3D_CORE_CROSS_BITMAP_H_

+

+#include <stdlib.h>

+

+#include "base/cross/bits.h"

+#include "core/cross/types.h"

+#include "core/cross/texture.h"

+

+class FilePath;

+

+namespace o3d {

+

+class MemoryReadStream;

+class RawData;

+class Pack;

+

+// Bitmap provides an API for basic image operations on bitmap images,

+// including scale and crop. The contents of bitmap can be created from

+// a RawData object via LoadFromRawData(), and also can be transfered

+// to mip of a Texure2D or a specific face of TextureCUBE via methods

+// in Texture.

+

+class Bitmap : public ParamObject {

+ public:

+  typedef SmartPointer<Bitmap> Ref;

+

+  explicit Bitmap(ServiceLocator* service_locator);

+  virtual ~Bitmap() {}

+

+  // We will fail to load images that are bigger than 4kx4k to avoid security

+  // risks. GPUs don't usually support bigger sizes anyway.

+  // The biggest bitmap buffer size with these dimensions is:

+  // 4k x 4k x 4xsizeof(float) x6 x4/3 (x6 for cube maps, x4/3 for mipmaps)

+  // That makes 2GB, representable in an unsigned int, so we will avoid wraps.

+  static const unsigned int kMaxImageDimension = 4096;

+  enum ImageFileType {

+    UNKNOWN,

+    TGA,

+    JPEG,

+    PNG,

+    DDS,

+  };

+

+  static bool CheckImageDimensions(unsigned int width, unsigned int height) {

+    return width > 0 && height > 0 &&

+        width <= kMaxImageDimension && height < kMaxImageDimension;

+  }

+

+  // Creates a copy of a bitmap, copying the pixels as well.

+  // Parameters:

+  //   source: the source bitmap.

+  void CopyDeepFrom(const Bitmap &source) {

+    Allocate(source.format_, source.width_, source.height_,

+             source.num_mipmaps_, source.is_cubemap_);

+    memcpy(image_data(), source.image_data(), GetTotalSize());

+  }

+

+  // Sets the bitmap parameters from another bitmap, stealing the pixel buffer

+  // from the source bitmap.

+  // Parameters:

+  //   source: the source bitmap.

+  void SetFrom(Bitmap *source) {

+    image_data_.reset();

+    format_ = source->format_;

+    width_ = source->width_;

+    height_ = source->height_;

+    num_mipmaps_ = source->num_mipmaps_;

+    is_cubemap_ = source->is_cubemap_;

+    image_data_.swap(source->image_data_);

+  }

+

+  // Allocates an uninitialized bitmap with specified parameters.

+  // Parameters:

+  //   format: the format of the pixels.

+  //   width: the width of the base image.

+  //   height: the height of the base image.

+  //   num_mipmaps: the number of mip-maps.

+  //   cube_map: true if creating a cube map.

+  void Allocate(Texture::Format format,

+                unsigned int width,

+                unsigned int height,

+                unsigned int num_mipmaps,

+                bool cube_map);

+

+  // Allocates a bitmap with initialized parameters.

+  // data is zero-initialized

+  void AllocateData() {

+    image_data_.reset(new unsigned char[GetTotalSize()]);

+    memset(image_data_.get(), 0, GetTotalSize());

+  }

+

+  // Frees the data owned by the bitmap.

+  void FreeData() {

+    image_data_.reset(NULL);

+  }

+

+  // Gets the total size of the bitmap data, counting all faces and mip levels.

+  unsigned int GetTotalSize() {

+    return (is_cubemap_ ? 6 : 1) *

+        GetMipChainSize(width_, height_, format_, num_mipmaps_);

+  }

+

+  // Computes the number of bytes of a texture pixel buffer.

+  static unsigned int GetBufferSize(unsigned int width,

+                                    unsigned int height,

+                                    Texture::Format format);

+

+  // Gets the image data for a given mip-map level and cube map face.

+  // Parameters:

+  //   level: mip level to get.

+  //   face: face of cube to get. This parameter is ignored if

+  //       this bitmap is not a cube map.

+  unsigned char *GetMipData(unsigned int level,

+                            TextureCUBE::CubeFace face) const;

+

+  unsigned char *image_data() const { return image_data_.get(); }

+  Texture::Format format() const { return format_; }

+  unsigned int width() const { return width_; }

+  unsigned int height() const { return height_; }

+  unsigned int num_mipmaps() const { return num_mipmaps_; }

+  bool is_cubemap() const { return is_cubemap_; }

+

+  // Returns whether or not the dimensions of the bitmap are power-of-two.

+  bool IsPOT() const {

+    return ((width_ & (width_ - 1)) == 0) && ((height_ & (height_ - 1)) == 0);

+  }

+

+  void set_format(Texture::Format format) { format_ = format; }

+  void set_width(unsigned int n) { width_ = n; }

+  void set_height(unsigned int n) { height_ = n; }

+  void set_num_mipmaps(unsigned int n) { num_mipmaps_ = n; }

+  void set_is_cubemap(bool is_cubemap) { is_cubemap_ = is_cubemap; }

+

+  // Loads a bitmap from a file.

+  // Parameters:

+  //   filename: the name of the file to load.

+  //   file_type: the type of file to load. If UNKNOWN, the file type will be

+  //              determined from the filename extension, and if it is not a

+  //              known extension, all the loaders will be tried.

+  //   generate_mipmaps: whether or not to generate all the mip-map levels.

+  bool LoadFromFile(const FilePath &filepath,

+                    ImageFileType file_type,

+                    bool generate_mipmaps);

+

+  // Loads a bitmap from a RawData object.

+  // Parameters:

+  //   raw_data: contains the bitmap data in one of the known formats

+  //   file_type: the format of the bitmap data. If UNKNOWN, the file type

+  //              will be determined from the extension from raw_data's uri

+  //              and if it is not a known extension, all the loaders will

+  //              be tried.

+  //   generate_mipmaps: whether or not to generate all the mip-map levels.

+  bool LoadFromRawData(RawData *raw_data,

+                       ImageFileType file_type,

+                       bool generate_mipmaps);

+

+  // Loads a bitmap from a MemoryReadStream.

+  // Parameters:

+  //   stream: a stream for the bitmap data in one of the known formats

+  //   filename: a filename (or uri) of the original bitmap data

+  //             (may be an empty string)

+  //   file_type: the format of the bitmap data. If UNKNOWN, the file type

+  //              will be determined from the extension of |filename|

+  //              and if it is not a known extension, all the loaders

+  //              will be tried.

+  //   generate_mipmaps: whether or not to generate all the mip-map levels.

+  bool LoadFromStream(MemoryReadStream *stream,

+                      const String &filename,

+                      ImageFileType file_type,

+                      bool generate_mipmaps);

+

+  bool LoadFromPNGStream(MemoryReadStream *stream,

+                         const String &filename,

+                         bool generate_mipmaps);

+

+  bool LoadFromTGAStream(MemoryReadStream *stream,

+                         const String &filename,

+                         bool generate_mipmaps);

+

+  bool LoadFromDDSStream(MemoryReadStream *stream,

+                         const String &filename,

+                         bool generate_mipmaps);

+

+  bool LoadFromJPEGStream(MemoryReadStream *stream,

+                          const String &filename,

+                          bool generate_mipmaps);

+

+  // Saves to a PNG file. The image must be of the ARGB8 format, be a 2D image

+  // with no mip-maps (only the base level).

+  // Parameters:

+  //   filename: the name of the file to into.

+  // Returns:

+  //   true if successful.

+  bool SaveToPNGFile(const char* filename);

+

+  // Checks that the alpha channel for the entire bitmap is 1.0

+  bool CheckAlphaIsOne() const;

+

+  // Copy pixels from source bitmap. Scales if the width and height of source

+  // and dest do not match.

+  // Parameters:

+  //   source_img: source bitmap which would be drawn.

+  //   source_x: x-coordinate of the starting pixel in the source image.

+  //   source_x: y-coordinate of the starting pixel in the source image.

+  //   source_width: width of the source image to draw.

+  //   source_height: Height of the source image to draw.

+  //   dest_x: x-coordinate of the starting pixel in the dest image.

+  //   dest_y: y-coordinate of the starting pixel in the dest image.

+  //   dest_width: width of the dest image to draw.

+  //   dest_height: height of the dest image to draw.

+  void DrawImage(Bitmap* source_img, int source_x, int source_y,

+                 int source_width, int source_height,

+                 int dest_x, int dest_y,

+                 int dest_width, int dest_height);

+

+  // Crop part of an image from src, scale it to an arbitrary size

+  // and paste in dest image. Utility function for all DrawImage

+  // function in bitmap and textures. Scale operation is based on

+  // Lanczos resampling.

+  // Note: this doesn't work for DXTC, or floating-point images.

+  //

+  // Parameters:

+  //   src: source image which would be copied from.

+  //   src_x: x-coordinate of the starting pixel in the src image.

+  //   src_y: y-coordinate of the starting pixel in the src image.

+  //   src_width: width of the part in src image to be croped.

+  //   src_height: height of the part in src image to be croped.

+  //   src_img_width: width of the src image.

+  //   src_img_height: height of the src image.

+  //   dest: dest image which would be copied to.

+  //   dest_x: x-coordinate of the starting pixel in the dest image.

+  //   dest_y: y-coordinate of the starting pixel in the dest image.

+  //   dest_width: width of the part in dest image to be pasted to.

+  //   dest_height: height of the part in dest image to be pasted to.

+  //   dest_img_width: width of the dest image.

+  //   dest_img_height: height of the src image.

+  //   component: size of each pixel in terms of array element.

+  // Returns:

+  //   true if crop and scale succeeds.

+  static void LanczosScale(const uint8* src,

+                           int src_x, int src_y,

+                           int src_width, int src_height,

+                           int src_img_width, int src_img_height,

+                           uint8* dest,

+                           int dest_x, int dest_y,

+                           int dest_width, int dest_height,

+                           int dest_img_width, int dest_img_height,

+                           int component);

+

+  // Detects the type of image file based on the filename.

+  static ImageFileType GetFileTypeFromFilename(const char *filename);

+  // Detects the type of image file based on the mime-type.

+  static ImageFileType GetFileTypeFromMimeType(const char *mime_type);

+

+  // Adds filler alpha byte (0xff) after every pixel. Assumes buffer was

+  // allocated with enough storage)

+  // can convert RGB -> RGBA, BGR -> BGRA, etc.

+  static void XYZToXYZA(unsigned char *image_data, int pixel_count);

+

+  // Swaps Red and Blue components in the image.

+  static void RGBAToBGRA(unsigned char *image_data, int pixel_count);

+

+  // Gets the number of mip-maps required for a full chain starting at

+  // width x height.

+  static unsigned int GetMipMapCount(unsigned int width, unsigned int height) {

+    return 1 + base::bits::Log2Floor(std::max(width, height));

+  }

+

+  // Gets the smallest power-of-two value that is at least as high as

+  // dimension. This is the POT dimension used in ScaleUpToPOT.

+  static unsigned int GetPOTSize(unsigned int dimension) {

+    return 1 << base::bits::Log2Ceiling(dimension);

+  }

+

+  // Gets the size of the buffer containing a mip-map chain, given its base

+  // width, height, format and number of mip-map levels.

+  static unsigned int GetMipChainSize(unsigned int base_width,

+                                      unsigned int base_height,

+                                      Texture::Format format,

+                                      unsigned int num_mipmaps);

+

+  // Generates mip-map levels for a single image, using the data from the base

+  // level.

+  // NOTE: this doesn't work for DXTC, or floating-point images.

+  //

+  // Parameters:

+  //   base_width: the width of the base image.

+  //   base_height: the height of the base image.

+  //   format: the format of the data.

+  //   num_mipmaps: the number of mipmaps to generate.

+  //   data: the data containing the base image, and enough space for the

+  //   mip-maps.

+  static bool GenerateMipmaps(unsigned int base_width,

+                              unsigned int base_height,

+                              Texture::Format format,

+                              unsigned int num_mipmaps,

+                              unsigned char *data);

+

+  // Scales an image up to power-of-two textures, using point filtering.

+  // NOTE: this doesn't work for DXTC, or floating-point images.

+  //

+  // Parameters:

+  //   width: the non-power-of-two width of the original image.

+  //   height: the non-power-of-two height of the original image.

+  //   format: the format of the data.

+  //   src: the data containing the source data of the original image.

+  //   dst: a buffer with enough space for the power-of-two version. Pixels are

+  //   written from the end to the beginning so dst can be the same buffer as

+  //   src.

+  static bool ScaleUpToPOT(unsigned int width,

+                           unsigned int height,

+                           Texture::Format format,

+                           const unsigned char *src,

+                           unsigned char *dst);

+

+  // Scales an image to an arbitrary size, using point filtering.

+  // NOTE: this doesn't work for DXTC, or floating-point images.

+  //

+  // Parameters:

+  //   src_width: the width of the original image.

+  //   src_height: the height of the original image.

+  //   format: the format of the data.

+  //   src: the data containing the source data of the original image.

+  //   dst_width: the width of the target image.

+  //   dst_height: the height of the target image.

+  //   dst: a buffer with enough space for the target version. Pixels are

+  //   written from the end to the beginning so dst can be the same buffer as

+  //   src if the transformation is an upscaling.

+  static bool Scale(unsigned int src_width,

+                    unsigned int src_height,

+                    Texture::Format format,

+                    const unsigned char *src,

+                    unsigned int dst_width,

+                    unsigned int dst_height,

+                    unsigned char *dst);

+

+  // adjust start points and boundaries when using DrawImage data

+  // in bitmap and textures.

+  // Parameters:

+  //   src_x: x-coordinate of the starting pixel in the source image.

+  //   src_y: y-coordinate of the starting pixel in the source image.

+  //   src_width: width of the source image to draw.

+  //   src_height: height of the source image to draw.

+  //   src_bmp_width: original width of source bitmap.

+  //   src_bmp_height: original height of source bitmap.

+  //   dest_x: x-coordinate of the starting pixel in the dest image.

+  //   dest_y: y-coordinate of the starting pixel in the dest image.

+  //   dest_width: width of the dest image to draw.

+  //   dest_height: height of the dest image to draw.

+  //   dest_bmp_width: original width of dest bitmap.

+  //   dest_bmp_height: original height of dest bitmap.

+  // Returns:

+  //   false if src or dest rectangle is out of boundaries.

+  static bool AdjustDrawImageBoundary(int* src_x, int* src_y,

+                                      int* src_width, int* src_height,

+                                      int src_bmp_width, int src_bmp_height,

+                                      int* dest_x, int* dest_y,

+                                      int* dest_width, int* dest_height,

+                                      int dest_bmp_width, int dest_bmp_height);

+

+ private:

+  friend class IClassManager;

+  static ObjectBase::Ref Create(ServiceLocator* service_locator);

+

+  // pointer to the raw bitmap data

+  scoped_array<uint8> image_data_;

+  // format of the texture this is meant to represent.

+  Texture::Format format_;

+  // width of the bitmap in pixels.

+  int width_;

+  // height of the bitmap in pixels.

+  int height_;

+  // number of mipmap levels in this texture.

+  unsigned int num_mipmaps_;

+  // is this cube-map data

+  bool is_cubemap_;

+

+  // utility function used in AdjustDrawImageBoundary.

+  // It adjusts start point and related measures

+  // for a specific dimension.

+  // Parameter:

+  //   src_a: the coordinate which is negative.

+  //   dest_a: same coordinate in the other image.

+  //   src_length: length measure of source image to draw.

+  //   dest_length: length measure of dest image to draw.

+  //   src_bmp_length: length measure of src image.

+  // Returns:

+  //   true if adjust is successful.

+  static bool AdjustDrawImageBoundHelper(int* src_a, int* dest_a,

+                                         int* src_length, int* dest_length,

+                                         int src_bmp_length);

+

+  // utility function for LanczosScale function.

+  // Given an image, It can scale the image in one dimension to the new

+  // length using a Lanczos3 windowsed-sinc filter. This filter has

+  // fairly large support, in choosing it we favor quality over speed.

+  // In parameters we assume the current dimension we are scaling is

+  // width, but by changing the parameter, we can easily using this

+  // function on height as well.

+  // Parameter:

+  //   src: source image which would be copied from.

+  //   src_x: x-coordinate of the starting pixel in the source image.

+  //   src_y: y-coordinate of the starting pixel in the source image.

+  //   width: width of the part in src image to be croped.

+  //   height: height of the part in src image to be croped.

+  //   src_bmp_width: original width of source bitmap.

+  //   src_bmp_height: original height of source bitmap.

+  //   dest: dest image which would be copied to.

+  //   dest_x: x-coordinate of the starting pixel in the dest image.

+  //   dest_y: y-coordinate of the starting pixel in the dest image.

+  //   dest_bmp_width: original width of dest bitmap.

+  //   dest_bmp_height: original height of dest bitmap.

+  //   isWidth: which dimension we are working on.

+  //   components: size of each pixel in terms of array element.

+  static void LanczosResize1D(const uint8* src, int src_x, int src_y,

+                              int width, int height,

+                              int src_bmp_width, int src_bmp_height,

+                              uint8* dest, int dest_x, int dest_y,

+                              int nwidth,

+                              int dest_bmp_width, int dest_bmp_height,

+                              bool isWidth, int components);

+

+  O3D_DECL_CLASS(Bitmap, ParamObject);

+  DISALLOW_COPY_AND_ASSIGN(Bitmap);

+};

+

+}  // namespace o3d

+

+#endif  // O3D_CORE_CROSS_BITMAP_H_

diff --git a/o3d/core/cross/bitmap_test.cc b/o3d/core/cross/bitmap_test.cc
index 1d832ef..230a589 100644
--- a/o3d/core/cross/bitmap_test.cc
+++ b/o3d/core/cross/bitmap_test.cc
@@ -1036,62 +1036,62 @@ static unsigned char kpng_8x4_drawImage_left[128] = {
 
 static unsigned char kpng_8x4_drawImage_scale_up[128] = {
   // expected result of scale up from 2x2 to 8x4.
-  0x3f, 0x3f, 0x3f, 0xff, 0x48, 0x48, 0x48, 0xff,
-  0x51, 0x51, 0x51, 0xff, 0x5a, 0x5a, 0x5a, 0xff,
-  0x64, 0x64, 0x64, 0xff, 0x6d, 0x6d, 0x6d, 0xff,
-  0x76, 0x76, 0x76, 0xff, 0x7f, 0x7f, 0x7f, 0xff,
-  0x2a, 0x2a, 0x2a, 0xff, 0x32, 0x32, 0x32, 0xff,
-  0x39, 0x39, 0x39, 0xff, 0x41, 0x41, 0x41, 0xff,
-  0x48, 0x48, 0x48, 0xff, 0x50, 0x50, 0x50, 0xff,
-  0x57, 0x57, 0x57, 0xff, 0x5f, 0x5f, 0x5f, 0xff,
-  0x15, 0x15, 0x15, 0xff, 0x1b, 0x1b, 0x1b, 0xff,
-  0x21, 0x21, 0x21, 0xff, 0x27, 0x27, 0x27, 0xff,
-  0x2d, 0x2d, 0x2d, 0xff, 0x33, 0x33, 0x33, 0xff,
-  0x39, 0x39, 0x39, 0xff, 0x3f, 0x3f, 0x3f, 0xff,
-  0x00, 0x00, 0x00, 0xff, 0x04, 0x04, 0x04, 0xff,
-  0x09, 0x09, 0x09, 0xff, 0x0d, 0x0d, 0x0d, 0xff,
-  0x12, 0x12, 0x12, 0xff, 0x16, 0x16, 0x16, 0xff,
-  0x1b, 0x1b, 0x1b, 0xff, 0x1f, 0x1f, 0x1f, 0xff,
+  0x38, 0x38, 0x38, 0xff, 0x43, 0x43, 0x43, 0xff,
+  0x52, 0x52, 0x52, 0xff, 0x63, 0x63, 0x63, 0xff,
+  0x77, 0x77, 0x77, 0xff, 0x88, 0x88, 0x88, 0xff,
+  0x96, 0x96, 0x96, 0xff, 0x90, 0x90, 0x90, 0xff,
+  0x25, 0x25, 0x25, 0xff, 0x2c, 0x2c, 0x2c, 0xff,
+  0x36, 0x36, 0x36, 0xff, 0x45, 0x45, 0x45, 0xff,
+  0x54, 0x54, 0x54, 0xff, 0x63, 0x63, 0x63, 0xff,
+  0x6e, 0x6e, 0x6e, 0xff, 0x69, 0x69, 0x69, 0xff,
+  0x0b, 0x0b, 0x0b, 0xff, 0x0d, 0x0d, 0x0d, 0xff,
+  0x13, 0x13, 0x13, 0xff, 0x1c, 0x1c, 0x1c, 0xff,
+  0x28, 0x28, 0x28, 0xff, 0x31, 0x31, 0x31, 0xff,
+  0x39, 0x39, 0x39, 0xff, 0x35, 0x35, 0x35, 0xff,
+  0x00, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0xff,
+  0x00, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0xff,
+  0x05, 0x05, 0x05, 0xff, 0x0c, 0x0c, 0x0c, 0xff,
+  0x11, 0x11, 0x11, 0xff, 0x0e, 0x0e, 0x0e, 0xff,
 };
 
 static unsigned char kpng_8x4_drawImage_scale_down[128] = {
   // expected result of scale down from 8x8 to 4x4.
-  0xa8, 0xa8, 0xa8, 0xff, 0xaf, 0xaf, 0xaf, 0xff,
-  0xb6, 0xb6, 0xb6, 0xff, 0xbd, 0xbd, 0xbd, 0xff,
+  0xa0, 0xa0, 0xa0, 0xff, 0xa7, 0xa7, 0xa7, 0xff,
+  0xad, 0xad, 0xad, 0xff, 0xb3, 0xb3, 0xb3, 0xff,
   0x38, 0x70, 0xe0, 0xff, 0x3a, 0x74, 0xe8, 0xff,
   0x3c, 0x78, 0xf0, 0xff, 0x3e, 0x7c, 0xf8, 0xff,
-  0x70, 0x70, 0x70, 0xff, 0x77, 0x77, 0x77, 0xff,
-  0x7e, 0x7e, 0x7e, 0xff, 0x85, 0x85, 0x85, 0xff,
+  0x6d, 0x6d, 0x6d, 0xff, 0x74, 0x74, 0x74, 0xff,
+  0x7a, 0x7a, 0x7a, 0xff, 0x80, 0x80, 0x80, 0xff,
   0x28, 0x50, 0xa0, 0xff, 0x2a, 0x54, 0xa8, 0xff,
   0x2c, 0x58, 0xb0, 0xff, 0x2e, 0x5c, 0xb8, 0xff,
-  0x38, 0x38, 0x38, 0xff, 0x3f, 0x3f, 0x3f, 0xff,
-  0x46, 0x46, 0x46, 0xff, 0x4d, 0x4d, 0x4d, 0xff,
+  0x3d, 0x3d, 0x3d, 0xff, 0x44, 0x44, 0x44, 0xff,
+  0x4a, 0x4a, 0x4a, 0xff, 0x50, 0x50, 0x50, 0xff,
   0x18, 0x30, 0x60, 0xff, 0x1a, 0x34, 0x68, 0xff,
   0x1c, 0x38, 0x70, 0xff, 0x1e, 0x3c, 0x78, 0xff,
-  0x00, 0x00, 0x00, 0xff, 0x07, 0x07, 0x07, 0xff,
-  0x0e, 0x0e, 0x0e, 0xff, 0x15, 0x15, 0x15, 0xff,
+  0x0a, 0x0a, 0x0a, 0xff, 0x11, 0x11, 0x11, 0xff,
+  0x17, 0x17, 0x17, 0xff, 0x1d, 0x1d, 0x1d, 0xff,
   0x08, 0x10, 0x20, 0xff, 0x0a, 0x14, 0x28, 0xff,
   0x0c, 0x18, 0x30, 0xff, 0x0e, 0x1c, 0x38, 0xff,
 };
 
 static unsigned char kpng_8x4_drawImage_scale_out[128] = {
   // expected result of scale src image larger than dest image.
-  0x63, 0x63, 0x63, 0xff, 0x65, 0x65, 0x65, 0xff,
-  0x67, 0x67, 0x67, 0xff, 0x69, 0x69, 0x69, 0xff,
-  0x6c, 0x6c, 0x6c, 0xff, 0x6e, 0x6e, 0x6e, 0xff,
-  0x70, 0x70, 0x70, 0xff, 0x72, 0x72, 0x72, 0xff,
-  0x53, 0x53, 0x53, 0xff, 0x55, 0x55, 0x55, 0xff,
-  0x57, 0x57, 0x57, 0xff, 0x59, 0x59, 0x59, 0xff,
+  0x64, 0x64, 0x64, 0xff, 0x66, 0x66, 0x66, 0xff,
+  0x68, 0x68, 0x68, 0xff, 0x6a, 0x6a, 0x6a, 0xff,
+  0x6d, 0x6d, 0x6d, 0xff, 0x6f, 0x6f, 0x6f, 0xff,
+  0x71, 0x71, 0x71, 0xff, 0x73, 0x73, 0x73, 0xff,
+  0x58, 0x58, 0x58, 0xff, 0x5a, 0x5a, 0x5a, 0xff,
   0x5c, 0x5c, 0x5c, 0xff, 0x5e, 0x5e, 0x5e, 0xff,
-  0x60, 0x60, 0x60, 0xff, 0x62, 0x62, 0x62, 0xff,
-  0x43, 0x43, 0x43, 0xff, 0x45, 0x45, 0x45, 0xff,
+  0x61, 0x61, 0x61, 0xff, 0x63, 0x63, 0x63, 0xff,
+  0x65, 0x65, 0x65, 0xff, 0x67, 0x67, 0x67, 0xff,
+  0x3e, 0x3e, 0x3e, 0xff, 0x40, 0x40, 0x40, 0xff,
+  0x42, 0x42, 0x42, 0xff, 0x44, 0x44, 0x44, 0xff,
   0x47, 0x47, 0x47, 0xff, 0x49, 0x49, 0x49, 0xff,
-  0x4c, 0x4c, 0x4c, 0xff, 0x4e, 0x4e, 0x4e, 0xff,
-  0x50, 0x50, 0x50, 0xff, 0x52, 0x52, 0x52, 0xff,
-  0x33, 0x33, 0x33, 0xff, 0x35, 0x35, 0x35, 0xff,
-  0x37, 0x37, 0x37, 0xff, 0x39, 0x39, 0x39, 0xff,
-  0x3c, 0x3c, 0x3c, 0xff, 0x3e, 0x3e, 0x3e, 0xff,
-  0x40, 0x40, 0x40, 0xff, 0x42, 0x42, 0x42, 0xff,
+  0x4b, 0x4b, 0x4b, 0xff, 0x4d, 0x4d, 0x4d, 0xff,
+  0x32, 0x32, 0x32, 0xff, 0x34, 0x34, 0x34, 0xff,
+  0x36, 0x36, 0x36, 0xff, 0x38, 0x38, 0x38, 0xff,
+  0x3b, 0x3b, 0x3b, 0xff, 0x3d, 0x3d, 0x3d, 0xff,
+  0x3f, 0x3f, 0x3f, 0xff, 0x41, 0x41, 0x41, 0xff,
 };
 
 static unsigned char kpng_8x4_drawImage_flip[128] = {
diff --git a/o3d/core/cross/texture.cc b/o3d/core/cross/texture.cc
index 0cc784f..008e2ef 100644
--- a/o3d/core/cross/texture.cc
+++ b/o3d/core/cross/texture.cc
@@ -123,7 +123,7 @@ void Texture2D::DrawImage(Bitmap* src_img,
   // the entire bitmap on dest image, just perform memcpy.
   if (src_x == 0 && src_y == 0 && dst_x == 0 && dst_y == 0 &&
       src_img->width() == mip_width && src_img->height() == mip_height &&
-      static_cast<unsigned int>(src_width) == src_img->width() && 
+      static_cast<unsigned int>(src_width) == src_img->width() &&
       static_cast<unsigned int>(src_height) == src_img->height() &&
       static_cast<unsigned int>(dst_width) == mip_width &&
       static_cast<unsigned int>(dst_height) == mip_height) {
@@ -157,12 +157,12 @@ void Texture2D::DrawImage(Bitmap* src_img,
   uint8* src_img_data = src_img->image_data();
   uint8* mip_data = static_cast<uint8*>(data);
 
-  Bitmap::BilinearInterpolateScale(src_img_data, src_x, src_y,
-                                   src_width, src_height,
-                                   src_img->width(), src_img->height(),
-                                   mip_data, dst_x, dst_y,
-                                   dst_width, dst_height,
-                                   mip_width, mip_height, components);
+  Bitmap::LanczosScale(src_img_data, src_x, src_y,
+                       src_width, src_height,
+                       src_img->width(), src_img->height(),
+                       mip_data, dst_x, dst_y,
+                       dst_width, dst_height,
+                       mip_width, mip_height, components);
 
   this->Unlock(dest_mip);
 }
@@ -312,12 +312,12 @@ void TextureCUBE::DrawImage(Bitmap* src_img,
   uint8* src_img_data = src_img->image_data();
   uint8* mip_data = static_cast<uint8*>(data);
 
-  Bitmap::BilinearInterpolateScale(src_img_data, src_x, src_y,
-                                   src_width, src_height,
-                                   src_img->width(), src_img->height(),
-                                   mip_data, dst_x, dst_y,
-                                   dst_width, dst_height,
-                                   mip_length, mip_length, components);
+  Bitmap::LanczosScale(src_img_data, src_x, src_y,
+                       src_width, src_height,
+                       src_img->width(), src_img->height(),
+                       mip_data, dst_x, dst_y,
+                       dst_width, dst_height,
+                       mip_length, mip_length, components);
 
   this->Unlock(dest_face, dest_mip);
 }