Add skia to the repository.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@16 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 338 insertions, 0 deletions

diff --git a/skia/images/SkScaledBitmapSampler.cpp b/skia/images/SkScaledBitmapSampler.cpp
new file mode 100644
index 0000000..529be61
--- /dev/null
+++ b/skia/images/SkScaledBitmapSampler.cpp
@@ -0,0 +1,338 @@
+/*
+ * Copyright 2007, Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); 
+ * you may not use this file except in compliance with the License. 
+ * You may obtain a copy of the License at 
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0 
+ *
+ * Unless required by applicable law or agreed to in writing, software 
+ * distributed under the License is distributed on an "AS IS" BASIS, 
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
+ * See the License for the specific language governing permissions and 
+ * limitations under the License.
+ */
+
+#include "SkScaledBitmapSampler.h"
+#include "SkBitmap.h"
+#include "SkColorPriv.h"
+#include "SkDither.h"
+
+// 8888
+
+static bool Sample_Gray_D8888(void* SK_RESTRICT dstRow,
+                              const uint8_t* SK_RESTRICT src,
+                              int width, int deltaSrc, int) {
+    SkPMColor* SK_RESTRICT dst = (SkPMColor*)dstRow;
+    for (int x = 0; x < width; x++) {
+        dst[x] = SkPackARGB32(0xFF, src[0], src[0], src[0]);
+        src += deltaSrc;
+    }
+    return false;
+}
+
+static bool Sample_RGBx_D8888(void* SK_RESTRICT dstRow,
+                              const uint8_t* SK_RESTRICT src,
+                              int width, int deltaSrc, int) {
+    SkPMColor* SK_RESTRICT dst = (SkPMColor*)dstRow;
+    for (int x = 0; x < width; x++) {
+        dst[x] = SkPackARGB32(0xFF, src[0], src[1], src[2]);
+        src += deltaSrc;
+    }
+    return false;
+}
+
+static bool Sample_RGBA_D8888(void* SK_RESTRICT dstRow,
+                              const uint8_t* SK_RESTRICT src,
+                              int width, int deltaSrc, int) {
+    SkPMColor* SK_RESTRICT dst = (SkPMColor*)dstRow;
+    unsigned alphaMask = 0xFF;
+    for (int x = 0; x < width; x++) {
+        unsigned alpha = src[3];
+        dst[x] = SkPreMultiplyARGB(alpha, src[0], src[1], src[2]);
+        src += deltaSrc;
+        alphaMask &= alpha;
+    }
+    return alphaMask != 0xFF;
+}
+
+// 565
+
+static bool Sample_Gray_D565(void* SK_RESTRICT dstRow,
+                             const uint8_t* SK_RESTRICT src,
+                             int width, int deltaSrc, int) {
+    uint16_t* SK_RESTRICT dst = (uint16_t*)dstRow;
+    for (int x = 0; x < width; x++) {
+        dst[x] = SkPack888ToRGB16(src[0], src[0], src[0]);
+        src += deltaSrc;
+    }
+    return false;
+}
+
+static bool Sample_Gray_D565_D(void* SK_RESTRICT dstRow,
+                               const uint8_t* SK_RESTRICT src,
+                               int width, int deltaSrc, int y) {
+    uint16_t* SK_RESTRICT dst = (uint16_t*)dstRow;
+    DITHER_565_SCAN(y);
+    for (int x = 0; x < width; x++) {
+        dst[x] = SkDitherRGBTo565(src[0], src[0], src[0], DITHER_VALUE(x));
+        src += deltaSrc;
+    }
+    return false;
+}
+
+static bool Sample_RGBx_D565(void* SK_RESTRICT dstRow,
+                             const uint8_t* SK_RESTRICT src,
+                             int width, int deltaSrc, int) {
+    uint16_t* SK_RESTRICT dst = (uint16_t*)dstRow;
+    for (int x = 0; x < width; x++) {
+        dst[x] = SkPack888ToRGB16(src[0], src[1], src[2]);
+        src += deltaSrc;
+    }
+    return false;
+}
+
+static bool Sample_RGBx_D565_D(void* SK_RESTRICT dstRow,
+                               const uint8_t* SK_RESTRICT src,
+                               int width, int deltaSrc, int y) {
+    uint16_t* SK_RESTRICT dst = (uint16_t*)dstRow;
+    DITHER_565_SCAN(y);
+    for (int x = 0; x < width; x++) {
+        dst[x] = SkDitherRGBTo565(src[0], src[1], src[2], DITHER_VALUE(x));
+        src += deltaSrc;
+    }
+    return false;
+}
+
+// 4444
+
+static bool Sample_Gray_D4444(void* SK_RESTRICT dstRow,
+                              const uint8_t* SK_RESTRICT src,
+                              int width, int deltaSrc, int) {
+    SkPMColor16* SK_RESTRICT dst = (SkPMColor16*)dstRow;
+    for (int x = 0; x < width; x++) {
+        unsigned gray = src[0] >> 4;
+        dst[x] = SkPackARGB4444(0xF, gray, gray, gray);
+        src += deltaSrc;
+    }
+    return false;
+}
+
+static bool Sample_Gray_D4444_D(void* SK_RESTRICT dstRow,
+                                const uint8_t* SK_RESTRICT src,
+                                int width, int deltaSrc, int y) {
+    SkPMColor16* SK_RESTRICT dst = (SkPMColor16*)dstRow;
+    DITHER_4444_SCAN(y);
+    for (int x = 0; x < width; x++) {
+        dst[x] = SkDitherARGB32To4444(0xFF, src[0], src[0], src[0],
+                                      DITHER_VALUE(x));
+        src += deltaSrc;
+    }
+    return false;
+}
+
+static bool Sample_RGBx_D4444(void* SK_RESTRICT dstRow,
+                              const uint8_t* SK_RESTRICT src,
+                              int width, int deltaSrc, int) {
+    SkPMColor16* SK_RESTRICT dst = (SkPMColor16*)dstRow;
+    for (int x = 0; x < width; x++) {
+        dst[x] = SkPackARGB4444(0xF, src[0] >> 4, src[1] >> 4, src[2] >> 4);
+        src += deltaSrc;
+    }
+    return false;
+}
+
+static bool Sample_RGBx_D4444_D(void* SK_RESTRICT dstRow,
+                                const uint8_t* SK_RESTRICT src,
+                                int width, int deltaSrc, int y) {
+    SkPMColor16* dst = (SkPMColor16*)dstRow;
+    DITHER_4444_SCAN(y);
+
+    for (int x = 0; x < width; x++) {
+        dst[x] = SkDitherARGB32To4444(0xFF, src[0], src[1], src[2],
+                                      DITHER_VALUE(x));
+        src += deltaSrc;
+    }
+    return false;
+}
+
+static bool Sample_RGBA_D4444(void* SK_RESTRICT dstRow,
+                              const uint8_t* SK_RESTRICT src,
+                              int width, int deltaSrc, int) {
+    SkPMColor16* SK_RESTRICT dst = (SkPMColor16*)dstRow;
+    unsigned alphaMask = 0xFF;
+
+    for (int x = 0; x < width; x++) {
+        unsigned alpha = src[3];
+        SkPMColor c = SkPreMultiplyARGB(alpha, src[0], src[1], src[2]);
+        dst[x] = SkPixel32ToPixel4444(c);
+        src += deltaSrc;
+        alphaMask &= alpha;
+    }
+    return alphaMask != 0xFF;
+}
+
+static bool Sample_RGBA_D4444_D(void* SK_RESTRICT dstRow,
+                                const uint8_t* SK_RESTRICT src,
+                                int width, int deltaSrc, int y) {
+    SkPMColor16* SK_RESTRICT dst = (SkPMColor16*)dstRow;
+    unsigned alphaMask = 0xFF;
+    DITHER_4444_SCAN(y);
+
+    for (int x = 0; x < width; x++) {
+        unsigned alpha = src[3];
+        SkPMColor c = SkPreMultiplyARGB(alpha, src[0], src[1], src[2]);
+        dst[x] = SkDitherARGB32To4444(c, DITHER_VALUE(x));
+        src += deltaSrc;
+        alphaMask &= alpha;
+    }
+    return alphaMask != 0xFF;
+}
+
+// Index
+
+static bool Sample_Index_DI(void* SK_RESTRICT dstRow,
+                            const uint8_t* SK_RESTRICT src,
+                            int width, int deltaSrc, int) {
+    if (1 == deltaSrc) {
+        memcpy(dstRow, src, width);
+    } else {
+        uint8_t* SK_RESTRICT dst = (uint8_t*)dstRow;
+        for (int x = 0; x < width; x++) {
+            dst[x] = src[0];
+            src += deltaSrc;
+        }
+    }
+    return false;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+#include "SkScaledBitmapSampler.h"
+
+SkScaledBitmapSampler::SkScaledBitmapSampler(int width, int height,
+                                             int sampleSize) {
+    if (width <= 0 || height <= 0) {
+        sk_throw();
+    }
+    
+    if (sampleSize <= 1) {
+        fScaledWidth = width;
+        fScaledHeight = height;
+        fX0 = fY0 = 0;
+        fDX = fDY = 1;
+        return;
+    }
+    
+    int dx = SkMin32(sampleSize, width);
+    int dy = SkMin32(sampleSize, height);
+    
+    fScaledWidth = width / dx;
+    fScaledHeight = height / dy;
+    
+    SkASSERT(fScaledWidth > 0);
+    SkASSERT(fScaledHeight > 0);
+    
+    fX0 = dx >> 1;
+    fY0 = dy >> 1;
+    
+    SkASSERT(fX0 >= 0 && fX0 < width);
+    SkASSERT(fY0 >= 0 && fY0 < height);
+    
+    fDX = dx;
+    fDY = dy;
+    
+    SkASSERT(fDX > 0 && (fX0 + fDX * (fScaledWidth - 1)) < width);
+    SkASSERT(fDY > 0 && (fY0 + fDY * (fScaledHeight - 1)) < height);
+    
+    fRowProc = NULL;
+}
+
+bool SkScaledBitmapSampler::begin(SkBitmap* dst, SrcConfig sc, bool dither) {
+    static const RowProc gProcs[] = {
+        // 8888 (no dither distinction)
+        Sample_Gray_D8888,  Sample_Gray_D8888,
+        Sample_RGBx_D8888,  Sample_RGBx_D8888,
+        Sample_RGBA_D8888,  Sample_RGBA_D8888,
+        NULL,               NULL,
+        // 565 (no alpha distinction)
+        Sample_Gray_D565,   Sample_Gray_D565_D,
+        Sample_RGBx_D565,   Sample_RGBx_D565_D,
+        Sample_RGBx_D565,   Sample_RGBx_D565_D,
+        NULL,               NULL,
+        // 4444
+        Sample_Gray_D4444,  Sample_Gray_D4444_D,
+        Sample_RGBx_D4444,  Sample_RGBx_D4444_D,
+        Sample_RGBA_D4444,  Sample_RGBA_D4444_D,
+        NULL,               NULL,
+        // Index8
+        NULL,               NULL,
+        NULL,               NULL,
+        NULL,               NULL,
+        Sample_Index_DI,    Sample_Index_DI,
+    };
+
+    
+    int index = 0;
+    if (dither) {
+        index += 1;
+    }
+    switch (sc) {
+        case SkScaledBitmapSampler::kGray:
+            fSrcPixelSize = 1;
+            index += 0;
+            break;
+        case SkScaledBitmapSampler::kRGB:
+            fSrcPixelSize = 3;
+            index += 2;
+            break;
+        case SkScaledBitmapSampler::kRGBX:
+            fSrcPixelSize = 4;
+            index += 2;
+            break;
+        case SkScaledBitmapSampler::kRGBA:
+            fSrcPixelSize = 4;
+            index += 4;
+            break;
+        case SkScaledBitmapSampler::kIndex:
+            fSrcPixelSize = 1;
+            index += 6;
+            break;
+        default:
+            return false;
+    }
+
+    switch (dst->config()) {
+        case SkBitmap::kARGB_8888_Config:
+            index += 0;
+            break;
+        case SkBitmap::kRGB_565_Config:
+            index += 8;
+            break;
+        case SkBitmap::kARGB_4444_Config:
+            index += 16;
+            break;
+        case SkBitmap::kIndex8_Config:
+            index += 24;
+            break;
+        default:
+            return false;
+    }
+    
+    fRowProc = gProcs[index];
+    fDstRow = (char*)dst->getPixels();
+    fDstRowBytes = dst->rowBytes();
+    fCurrY = 0;
+    return fRowProc != NULL;
+}
+
+bool SkScaledBitmapSampler::next(const uint8_t* SK_RESTRICT src) {
+    SkASSERT((unsigned)fCurrY < (unsigned)fScaledHeight);
+
+    bool hadAlpha = fRowProc(fDstRow, src + fX0 * fSrcPixelSize, fScaledWidth,
+                             fDX * fSrcPixelSize, fCurrY);
+    fDstRow += fDstRowBytes;
+    fCurrY += 1;
+    return hadAlpha;
+}