diff options
author | commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2013-08-14 22:02:23 +0000 |
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committer | commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2013-08-14 22:02:23 +0000 |
commit | 5d18cee176b8a8c01138a43fd561881090ebc810 (patch) | |
tree | 6369854951d0db95bf126d6441b661e3a8c5317b | |
parent | ab882bf205affcd29f62f764681bfdf09fde004e (diff) |
Unpremultiply SkBitmaps for PDF output
BUG=skia:236, chromium:175548
R=vandebo@chromium.org, edisonn@google.com, reed@google.com
Author: richardlin@chromium.org
Review URL: https://chromiumcodereview.appspot.com/22329003
git-svn-id: http://skia.googlecode.com/svn/trunk@10725 2bbb7eff-a529-9590-31e7-b0007b416f81
-rw-r--r-- | gm/bitmappremul.cpp | 131 | ||||
-rw-r--r-- | gyp/gmslides.gypi | 1 | ||||
-rw-r--r-- | src/pdf/SkPDFImage.cpp | 88 |
3 files changed, 200 insertions, 20 deletions
diff --git a/gm/bitmappremul.cpp b/gm/bitmappremul.cpp new file mode 100644 index 0000000000..9f0c1e8cb9 --- /dev/null +++ b/gm/bitmappremul.cpp @@ -0,0 +1,131 @@ +/* + * Copyright 2013 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#include "gm.h" +#include "SkBitmap.h" +#include "SkCanvas.h" +#include "SkColorPriv.h" + +/** + * This GM checks that bitmap pixels are unpremultiplied before being exported + * to other formats. If unpremultiplication is implemented properly, this + * GM should come out completely white. If not, this GM looks like a row of two + * greyscale gradients above a row of grey lines. + * This tests both the ARGB4444 and ARGB8888 bitmap configurations. + */ + +static const int SLIDE_SIZE = 256; +static const int PIXEL_SIZE_8888 = SLIDE_SIZE / 256; +static const int PIXEL_SIZE_4444 = SLIDE_SIZE / 16; + +static SkBitmap init_bitmap(SkBitmap::Config config) { + SkBitmap bitmap; + bitmap.setConfig(config, SLIDE_SIZE, SLIDE_SIZE); + bitmap.allocPixels(); + bitmap.eraseColor(SK_ColorWHITE); + return bitmap; +} + +static SkBitmap make_argb8888_gradient() { + SkBitmap bitmap = init_bitmap(SkBitmap::kARGB_8888_Config); + uint8_t rowColor = 0; + for (int y = 0; y < SLIDE_SIZE; y++) { + uint32_t* dst = bitmap.getAddr32(0, y); + for (int x = 0; x < SLIDE_SIZE; x++) { + dst[x] = SkPackARGB32(rowColor, rowColor, + rowColor, rowColor); + } + if (y % PIXEL_SIZE_8888 == PIXEL_SIZE_8888 - 1) { + rowColor++; + } + } + return bitmap; +} + +static SkBitmap make_argb4444_gradient() { + SkBitmap bitmap = init_bitmap(SkBitmap::kARGB_4444_Config); + uint8_t rowColor = 0; + for (int y = 0; y < SLIDE_SIZE; y++) { + uint16_t* dst = bitmap.getAddr16(0, y); + for (int x = 0; x < SLIDE_SIZE; x++) { + dst[x] = SkPackARGB4444(rowColor, rowColor, + rowColor, rowColor); + } + if (y % PIXEL_SIZE_4444 == PIXEL_SIZE_4444 - 1) { + rowColor++; + } + } + return bitmap; +} + +static SkBitmap make_argb8888_stripes() { + SkBitmap bitmap = init_bitmap(SkBitmap::kARGB_8888_Config); + uint8_t rowColor = 0; + for (int y = 0; y < SLIDE_SIZE; y++) { + uint32_t* dst = bitmap.getAddr32(0, y); + for (int x = 0; x < SLIDE_SIZE; x++) { + dst[x] = SkPackARGB32(rowColor, rowColor, + rowColor, rowColor); + } + if (rowColor == 0) { + rowColor = 255; + } else { + rowColor = 0; + } + } + return bitmap; +} + +static SkBitmap make_argb4444_stripes() { + SkBitmap bitmap = init_bitmap(SkBitmap::kARGB_4444_Config); + uint8_t rowColor = 0;; + for (int y = 0; y < SLIDE_SIZE; y++) { + uint16_t* dst = bitmap.getAddr16(0, y); + for (int x = 0; x < SLIDE_SIZE; x++) { + dst[x] = SkPackARGB4444(rowColor, rowColor, + rowColor, rowColor); + } + if (rowColor == 0) { + rowColor = 15; + } else { + rowColor = 0; + } + } + return bitmap; +} + +namespace skiagm { + +class BitmapPremulGM : public GM { +public: + BitmapPremulGM() { + this->setBGColor(0xFFFFFFFF); + } + +protected: + SkString onShortName() SK_OVERRIDE { + return SkString("bitmap_premul"); + } + + virtual SkISize onISize() SK_OVERRIDE { + return SkISize::Make(512, 512); + } + + virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE { + SkScalar slideSize = SLIDE_SIZE; + canvas->drawBitmap(make_argb8888_gradient(), 0, 0); + canvas->drawBitmap(make_argb4444_gradient(), slideSize, 0); + canvas->drawBitmap(make_argb8888_stripes(), 0, slideSize); + canvas->drawBitmap(make_argb4444_stripes(), slideSize, slideSize); + } + +private: + typedef GM INHERITED; +}; + +DEF_GM( return new BitmapPremulGM; ) +} diff --git a/gyp/gmslides.gypi b/gyp/gmslides.gypi index bc0fc65415..524d63a2a7 100644 --- a/gyp/gmslides.gypi +++ b/gyp/gmslides.gypi @@ -12,6 +12,7 @@ '../gm/bitmapcopy.cpp', '../gm/bitmapmatrix.cpp', '../gm/bitmapfilters.cpp', + '../gm/bitmappremul.cpp', '../gm/bitmaprect.cpp', '../gm/bitmaprecttest.cpp', '../gm/bitmapscroll.cpp', diff --git a/src/pdf/SkPDFImage.cpp b/src/pdf/SkPDFImage.cpp index a5cb4c20d1..a4872e25f8 100644 --- a/src/pdf/SkPDFImage.cpp +++ b/src/pdf/SkPDFImage.cpp @@ -18,6 +18,57 @@ namespace { +static void unpremultiply_and_pack_argb8888(uint32_t src, uint8_t dst[3]) { + uint8_t alpha = SkGetPackedA32(src); + if (alpha != SK_AlphaOPAQUE) { + SkColor unpremul = SkUnPreMultiply::PMColorToColor(src); + dst[0] = SkColorGetR(unpremul); + dst[1] = SkColorGetG(unpremul); + dst[2] = SkColorGetB(unpremul); + } else { + dst[0] = SkGetPackedR32(src); + dst[1] = SkGetPackedG32(src); + dst[2] = SkGetPackedB32(src); + } +} + +static void unpremultiply_and_pack_argb4444(uint16_t src0, uint16_t src1, + uint8_t dst[3]) { + // Unpack and transform the alpha values from 4 bits to 8 bits. + // This is necessary since the unpremultiply functions expect to work in + // 8-bit space, but we are passing in 4-bit values. Since we scale up + // the alpha, we scale down the amount the value is increased by, so that + // the results are correct for 4-bit color components. + uint8_t alpha0 = SkGetPackedA4444(src0); + alpha0 = alpha0 | (alpha0 << 4); + if (alpha0 != SK_AlphaOPAQUE) { + SkUnPreMultiply::Scale scale0 = SkUnPreMultiply::GetScale(alpha0); + dst[0] = SkUnPreMultiply::ApplyScale(scale0, + SkGetPackedR4444(src0)) << 4; + dst[0] |= SkUnPreMultiply::ApplyScale(scale0, SkGetPackedG4444(src0)); + dst[1] = SkUnPreMultiply::ApplyScale(scale0, + SkGetPackedB4444(src0)) << 4; + } else { + dst[0] = SkGetPackedR4444(src0) << 4; + dst[0] |= SkGetPackedG4444(src0); + dst[1] = SkGetPackedB4444(src0) << 4; + } + + uint8_t alpha1 = SkGetPackedA4444(src1); + alpha1 = alpha1 | (alpha1 << 4); + if (alpha1 != SK_AlphaOPAQUE) { + SkUnPreMultiply::Scale scale1 = SkUnPreMultiply::GetScale(alpha1); + dst[1] |= SkUnPreMultiply::ApplyScale(scale1, SkGetPackedR4444(src1)); + dst[2] = SkUnPreMultiply::ApplyScale(scale1, + SkGetPackedG4444(src1)) << 4; + dst[2] |= SkUnPreMultiply::ApplyScale(scale1, SkGetPackedB4444(src1)); + } else { + dst[1] |= SkGetPackedR4444(src1); + dst[2] = SkGetPackedG4444(src1) << 4; + dst[2] |= SkGetPackedB4444(src1); + } +} + void extractImageData(const SkBitmap& bitmap, const SkIRect& srcRect, SkStream** imageData, SkStream** alphaData) { SkMemoryStream* image = NULL; @@ -49,36 +100,35 @@ void extractImageData(const SkBitmap& bitmap, const SkIRect& srcRect, uint16_t* src = bitmap.getAddr16(0, y); int x; for (x = srcRect.fLeft; x + 1 < srcRect.fRight; x += 2) { - dst[0] = (SkGetPackedR4444(src[x]) << 4) | - SkGetPackedG4444(src[x]); - dst[1] = (SkGetPackedB4444(src[x]) << 4) | - SkGetPackedR4444(src[x + 1]); - dst[2] = (SkGetPackedG4444(src[x + 1]) << 4) | - SkGetPackedB4444(src[x + 1]); - dst += 3; alphaDst[0] = (SkGetPackedA4444(src[x]) << 4) | - SkGetPackedA4444(src[x + 1]); - if (alphaDst[0] != 0xFF) { + SkGetPackedA4444(src[x + 1]); + if (alphaDst[0] != SK_AlphaOPAQUE) { hasAlpha = true; } if (alphaDst[0]) { isTransparent = false; } + unpremultiply_and_pack_argb4444(src[x], src[x + 1], dst); alphaDst++; + dst += 3; } if (srcRect.width() & 1) { - dst[0] = (SkGetPackedR4444(src[x]) << 4) | - SkGetPackedG4444(src[x]); - dst[1] = (SkGetPackedB4444(src[x]) << 4); - dst += 2; - alphaDst[0] = (SkGetPackedA4444(src[x]) << 4); + alphaDst[0] = SkGetPackedA4444(src[x]) << 4; + // Use a buffer to translate from the usual 2 4444 values + // in 3 bytes to the single 4444 value in 2 bytes. + uint8_t buffer[3]; if (alphaDst[0] != 0xF0) { hasAlpha = true; } if (alphaDst[0] & 0xF0) { isTransparent = false; } + unpremultiply_and_pack_argb4444(src[x], 0x00, buffer); + dst[0] = buffer[0]; + dst[1] = buffer[1]; + alphaDst++; + dst += 2; } } break; @@ -108,18 +158,16 @@ void extractImageData(const SkBitmap& bitmap, const SkIRect& srcRect, for (int y = srcRect.fTop; y < srcRect.fBottom; y++) { uint32_t* src = bitmap.getAddr32(0, y); for (int x = srcRect.fLeft; x < srcRect.fRight; x++) { - dst[0] = SkGetPackedR32(src[x]); - dst[1] = SkGetPackedG32(src[x]); - dst[2] = SkGetPackedB32(src[x]); - dst += 3; alphaDst[0] = SkGetPackedA32(src[x]); - if (alphaDst[0] != 0xFF) { + if (alphaDst[0] != SK_AlphaOPAQUE) { hasAlpha = true; } - if (alphaDst[0]) { + if (alphaDst[0] != SK_AlphaTRANSPARENT) { isTransparent = false; } + unpremultiply_and_pack_argb8888(src[x], dst); alphaDst++; + dst += 3; } } break; |