diff options
Diffstat (limited to 'gfx/skbitmap_operations.cc')
| -rw-r--r-- | gfx/skbitmap_operations.cc | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/gfx/skbitmap_operations.cc b/gfx/skbitmap_operations.cc new file mode 100644 index 0000000..5ce8ebd --- /dev/null +++ b/gfx/skbitmap_operations.cc @@ -0,0 +1,356 @@ +// Copyright (c) 2009 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "gfx/skbitmap_operations.h" + +#include <algorithm> + +#include "base/logging.h" +#include "third_party/skia/include/core/SkBitmap.h" +#include "third_party/skia/include/core/SkCanvas.h" +#include "third_party/skia/include/core/SkColorPriv.h" +#include "third_party/skia/include/core/SkUnPreMultiply.h" + +// static +SkBitmap SkBitmapOperations::CreateInvertedBitmap(const SkBitmap& image) { + DCHECK(image.config() == SkBitmap::kARGB_8888_Config); + + SkAutoLockPixels lock_image(image); + + SkBitmap inverted; + inverted.setConfig(SkBitmap::kARGB_8888_Config, image.width(), image.height(), + 0); + inverted.allocPixels(); + inverted.eraseARGB(0, 0, 0, 0); + + for (int y = 0; y < image.height(); ++y) { + uint32* image_row = image.getAddr32(0, y); + uint32* dst_row = inverted.getAddr32(0, y); + + for (int x = 0; x < image.width(); ++x) { + uint32 image_pixel = image_row[x]; + dst_row[x] = (image_pixel & 0xFF000000) | + (0x00FFFFFF - (image_pixel & 0x00FFFFFF)); + } + } + + return inverted; +} + +// static +SkBitmap SkBitmapOperations::CreateSuperimposedBitmap(const SkBitmap& first, + const SkBitmap& second) { + DCHECK(first.width() == second.width()); + DCHECK(first.height() == second.height()); + DCHECK(first.bytesPerPixel() == second.bytesPerPixel()); + DCHECK(first.config() == SkBitmap::kARGB_8888_Config); + + SkAutoLockPixels lock_first(first); + SkAutoLockPixels lock_second(second); + + SkBitmap superimposed; + superimposed.setConfig(SkBitmap::kARGB_8888_Config, + first.width(), first.height()); + superimposed.allocPixels(); + superimposed.eraseARGB(0, 0, 0, 0); + + SkCanvas canvas(superimposed); + + SkRect rect; + rect.fLeft = 0; + rect.fTop = 0; + rect.fRight = SkIntToScalar(first.width()); + rect.fBottom = SkIntToScalar(first.height()); + + canvas.drawBitmapRect(first, NULL, rect); + canvas.drawBitmapRect(second, NULL, rect); + + return superimposed; +} + +// static +SkBitmap SkBitmapOperations::CreateBlendedBitmap(const SkBitmap& first, + const SkBitmap& second, + double alpha) { + DCHECK((alpha >= 0) && (alpha <= 1)); + DCHECK(first.width() == second.width()); + DCHECK(first.height() == second.height()); + DCHECK(first.bytesPerPixel() == second.bytesPerPixel()); + DCHECK(first.config() == SkBitmap::kARGB_8888_Config); + + // Optimize for case where we won't need to blend anything. + static const double alpha_min = 1.0 / 255; + static const double alpha_max = 254.0 / 255; + if (alpha < alpha_min) + return first; + else if (alpha > alpha_max) + return second; + + SkAutoLockPixels lock_first(first); + SkAutoLockPixels lock_second(second); + + SkBitmap blended; + blended.setConfig(SkBitmap::kARGB_8888_Config, first.width(), first.height(), + 0); + blended.allocPixels(); + blended.eraseARGB(0, 0, 0, 0); + + double first_alpha = 1 - alpha; + + for (int y = 0; y < first.height(); ++y) { + uint32* first_row = first.getAddr32(0, y); + uint32* second_row = second.getAddr32(0, y); + uint32* dst_row = blended.getAddr32(0, y); + + for (int x = 0; x < first.width(); ++x) { + uint32 first_pixel = first_row[x]; + uint32 second_pixel = second_row[x]; + + int a = static_cast<int>((SkColorGetA(first_pixel) * first_alpha) + + (SkColorGetA(second_pixel) * alpha)); + int r = static_cast<int>((SkColorGetR(first_pixel) * first_alpha) + + (SkColorGetR(second_pixel) * alpha)); + int g = static_cast<int>((SkColorGetG(first_pixel) * first_alpha) + + (SkColorGetG(second_pixel) * alpha)); + int b = static_cast<int>((SkColorGetB(first_pixel) * first_alpha) + + (SkColorGetB(second_pixel) * alpha)); + + dst_row[x] = SkColorSetARGB(a, r, g, b); + } + } + + return blended; +} + +// static +SkBitmap SkBitmapOperations::CreateMaskedBitmap(const SkBitmap& rgb, + const SkBitmap& alpha) { + DCHECK(rgb.width() == alpha.width()); + DCHECK(rgb.height() == alpha.height()); + DCHECK(rgb.bytesPerPixel() == alpha.bytesPerPixel()); + DCHECK(rgb.config() == SkBitmap::kARGB_8888_Config); + DCHECK(alpha.config() == SkBitmap::kARGB_8888_Config); + + SkBitmap masked; + masked.setConfig(SkBitmap::kARGB_8888_Config, rgb.width(), rgb.height(), 0); + masked.allocPixels(); + masked.eraseARGB(0, 0, 0, 0); + + SkAutoLockPixels lock_rgb(rgb); + SkAutoLockPixels lock_alpha(alpha); + SkAutoLockPixels lock_masked(masked); + + for (int y = 0; y < masked.height(); ++y) { + uint32* rgb_row = rgb.getAddr32(0, y); + uint32* alpha_row = alpha.getAddr32(0, y); + uint32* dst_row = masked.getAddr32(0, y); + + for (int x = 0; x < masked.width(); ++x) { + SkColor rgb_pixel = SkUnPreMultiply::PMColorToColor(rgb_row[x]); + int alpha = SkAlphaMul(SkColorGetA(rgb_pixel), SkColorGetA(alpha_row[x])); + dst_row[x] = SkColorSetARGB(alpha, + SkAlphaMul(SkColorGetR(rgb_pixel), alpha), + SkAlphaMul(SkColorGetG(rgb_pixel), alpha), + SkAlphaMul(SkColorGetB(rgb_pixel), alpha)); + } + } + + return masked; +} + +// static +SkBitmap SkBitmapOperations::CreateButtonBackground(SkColor color, + const SkBitmap& image, + const SkBitmap& mask) { + DCHECK(image.config() == SkBitmap::kARGB_8888_Config); + DCHECK(mask.config() == SkBitmap::kARGB_8888_Config); + + SkBitmap background; + background.setConfig( + SkBitmap::kARGB_8888_Config, mask.width(), mask.height(), 0); + background.allocPixels(); + + double bg_a = SkColorGetA(color); + double bg_r = SkColorGetR(color); + double bg_g = SkColorGetG(color); + double bg_b = SkColorGetB(color); + + SkAutoLockPixels lock_mask(mask); + SkAutoLockPixels lock_image(image); + SkAutoLockPixels lock_background(background); + + for (int y = 0; y < mask.height(); ++y) { + uint32* dst_row = background.getAddr32(0, y); + uint32* image_row = image.getAddr32(0, y % image.height()); + uint32* mask_row = mask.getAddr32(0, y); + + for (int x = 0; x < mask.width(); ++x) { + uint32 image_pixel = image_row[x % image.width()]; + + double img_a = SkColorGetA(image_pixel); + double img_r = SkColorGetR(image_pixel); + double img_g = SkColorGetG(image_pixel); + double img_b = SkColorGetB(image_pixel); + + double img_alpha = static_cast<double>(img_a) / 255.0; + double img_inv = 1 - img_alpha; + + double mask_a = static_cast<double>(SkColorGetA(mask_row[x])) / 255.0; + + dst_row[x] = SkColorSetARGB( + static_cast<int>(std::min(255.0, bg_a + img_a) * mask_a), + static_cast<int>(((bg_r * img_inv) + (img_r * img_alpha)) * mask_a), + static_cast<int>(((bg_g * img_inv) + (img_g * img_alpha)) * mask_a), + static_cast<int>(((bg_b * img_inv) + (img_b * img_alpha)) * mask_a)); + } + } + + return background; +} + + +// static +SkBitmap SkBitmapOperations::CreateHSLShiftedBitmap( + const SkBitmap& bitmap, + color_utils::HSL hsl_shift) { + DCHECK(bitmap.empty() == false); + DCHECK(bitmap.config() == SkBitmap::kARGB_8888_Config); + + SkBitmap shifted; + shifted.setConfig(SkBitmap::kARGB_8888_Config, bitmap.width(), + bitmap.height(), 0); + shifted.allocPixels(); + shifted.eraseARGB(0, 0, 0, 0); + shifted.setIsOpaque(false); + + SkAutoLockPixels lock_bitmap(bitmap); + SkAutoLockPixels lock_shifted(shifted); + + // Loop through the pixels of the original bitmap. + for (int y = 0; y < bitmap.height(); ++y) { + SkPMColor* pixels = bitmap.getAddr32(0, y); + SkPMColor* tinted_pixels = shifted.getAddr32(0, y); + + for (int x = 0; x < bitmap.width(); ++x) { + tinted_pixels[x] = SkPreMultiplyColor(color_utils::HSLShift( + SkUnPreMultiply::PMColorToColor(pixels[x]), hsl_shift)); + } + } + + return shifted; +} + +// static +SkBitmap SkBitmapOperations::CreateTiledBitmap(const SkBitmap& source, + int src_x, int src_y, + int dst_w, int dst_h) { + DCHECK(source.getConfig() == SkBitmap::kARGB_8888_Config); + + SkBitmap cropped; + cropped.setConfig(SkBitmap::kARGB_8888_Config, dst_w, dst_h, 0); + cropped.allocPixels(); + cropped.eraseARGB(0, 0, 0, 0); + + SkAutoLockPixels lock_source(source); + SkAutoLockPixels lock_cropped(cropped); + + // Loop through the pixels of the original bitmap. + for (int y = 0; y < dst_h; ++y) { + int y_pix = (src_y + y) % source.height(); + while (y_pix < 0) + y_pix += source.height(); + + uint32* source_row = source.getAddr32(0, y_pix); + uint32* dst_row = cropped.getAddr32(0, y); + + for (int x = 0; x < dst_w; ++x) { + int x_pix = (src_x + x) % source.width(); + while (x_pix < 0) + x_pix += source.width(); + + dst_row[x] = source_row[x_pix]; + } + } + + return cropped; +} + +// static +SkBitmap SkBitmapOperations::DownsampleByTwoUntilSize(const SkBitmap& bitmap, + int min_w, int min_h) { + if ((bitmap.width() <= min_w) || (bitmap.height() <= min_h) || + (min_w < 0) || (min_h < 0)) + return bitmap; + + // Since bitmaps are refcounted, this copy will be fast. + SkBitmap current = bitmap; + while ((current.width() >= min_w * 2) && (current.height() >= min_h * 2) && + (current.width() > 1) && (current.height() > 1)) + current = DownsampleByTwo(current); + return current; +} + +// static +SkBitmap SkBitmapOperations::DownsampleByTwo(const SkBitmap& bitmap) { + // Handle the nop case. + if ((bitmap.width() <= 1) || (bitmap.height() <= 1)) + return bitmap; + + SkBitmap result; + result.setConfig(SkBitmap::kARGB_8888_Config, + (bitmap.width() + 1) / 2, (bitmap.height() + 1) / 2); + result.allocPixels(); + + SkAutoLockPixels lock(bitmap); + for (int dest_y = 0; dest_y < result.height(); ++dest_y) { + for (int dest_x = 0; dest_x < result.width(); ++dest_x) { + // This code is based on downsampleby2_proc32 in SkBitmap.cpp. It is very + // clever in that it does two channels at once: alpha and green ("ag") + // and red and blue ("rb"). Each channel gets averaged across 4 pixels + // to get the result. + int src_x = dest_x << 1; + int src_y = dest_y << 1; + const SkPMColor* cur_src = bitmap.getAddr32(src_x, src_y); + SkPMColor tmp, ag, rb; + + // Top left pixel of the 2x2 block. + tmp = *cur_src; + ag = (tmp >> 8) & 0xFF00FF; + rb = tmp & 0xFF00FF; + if (src_x < (bitmap.width() - 1)) + ++cur_src; + + // Top right pixel of the 2x2 block. + tmp = *cur_src; + ag += (tmp >> 8) & 0xFF00FF; + rb += tmp & 0xFF00FF; + if (src_y < (bitmap.height() - 1)) + cur_src = bitmap.getAddr32(src_x, src_y + 1); + else + cur_src = bitmap.getAddr32(src_x, src_y); // Move back to the first. + + // Bottom left pixel of the 2x2 block. + tmp = *cur_src; + ag += (tmp >> 8) & 0xFF00FF; + rb += tmp & 0xFF00FF; + if (src_x < (bitmap.width() - 1)) + ++cur_src; + + // Bottom right pixel of the 2x2 block. + tmp = *cur_src; + ag += (tmp >> 8) & 0xFF00FF; + rb += tmp & 0xFF00FF; + + // Put the channels back together, dividing each by 4 to get the average. + // |ag| has the alpha and green channels shifted right by 8 bits from + // there they should end up, so shifting left by 6 gives them in the + // correct position divided by 4. + *result.getAddr32(dest_x, dest_y) = + ((rb >> 2) & 0xFF00FF) | ((ag << 6) & 0xFF00FF00); + } + } + + return result; +} + |