grab from latest android
git-svn-id: http://skia.googlecode.com/svn/trunk@27 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/images/SkScaledBitmapSampler.cpp b/src/images/SkScaledBitmapSampler.cpp
new file mode 100644
index 0000000..15f4432
--- /dev/null
+++ b/src/images/SkScaledBitmapSampler.cpp
@@ -0,0 +1,338 @@
+/*
+ * Copyright 2007, The Android Open Source Project
+ *
+ * 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;
+}