Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(9)

Issues Search
    My Issues | Starred     Open | Closed | All

Unified Diff: skia/images/SkImageDecoder_libpng.cpp

Issue 113827: Remove the remainder of the skia source code from the Chromium repo.... (Closed) Base URL: svn://chrome-svn/chrome/trunk/src/
Patch Set: Created 11 years, 7 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « skia/images/SkImageDecoder_libjpeg.cpp ('k') | skia/images/SkImageDecoder_libpvjpeg.cpp » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: skia/images/SkImageDecoder_libpng.cpp
===================================================================
--- skia/images/SkImageDecoder_libpng.cpp (revision 16859)
+++ skia/images/SkImageDecoder_libpng.cpp (working copy)
@@ -1,795 +0,0 @@
-/* libs/graphics/images/SkImageDecoder_libpng.cpp
-**
-** Copyright 2006, 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 "SkImageDecoder.h"
-#include "SkColor.h"
-#include "SkColorPriv.h"
-#include "SkDither.h"
-#include "SkMath.h"
-#include "SkScaledBitmapSampler.h"
-#include "SkStream.h"
-#include "SkTemplates.h"
-#include "SkUtils.h"
-
-extern "C" {
-#include "png.h"
-}
-
-class SkPNGImageDecoder : public SkImageDecoder {
-public:
- virtual Format getFormat() const {
- return kPNG_Format;
- }
-
-protected:
- virtual bool onDecode(SkStream* stream, SkBitmap* bm,
- SkBitmap::Config pref, Mode);
-};
-
-#ifndef png_jmpbuf
-# define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
-#endif
-
-#define PNG_BYTES_TO_CHECK 4
-
-/* Automatically clean up after throwing an exception */
-struct PNGAutoClean {
- PNGAutoClean(png_structp p, png_infop i): png_ptr(p), info_ptr(i) {}
- ~PNGAutoClean() {
- png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
- }
-private:
- png_structp png_ptr;
- png_infop info_ptr;
-};
-
-SkImageDecoder* SkImageDecoder_PNG_Factory(SkStream* stream) {
- char buf[PNG_BYTES_TO_CHECK];
- if (stream->read(buf, PNG_BYTES_TO_CHECK) == PNG_BYTES_TO_CHECK &&
- !png_sig_cmp((png_bytep) buf, (png_size_t)0, PNG_BYTES_TO_CHECK)) {
- return SkNEW(SkPNGImageDecoder);
- }
- return NULL;
-}
-
-static void sk_read_fn(png_structp png_ptr, png_bytep data, png_size_t length) {
- SkStream* sk_stream = (SkStream*) png_ptr->io_ptr;
- size_t bytes = sk_stream->read(data, length);
- if (bytes != length) {
- png_error(png_ptr, "Read Error!");
- }
-}
-
-static int sk_read_user_chunk(png_structp png_ptr, png_unknown_chunkp chunk) {
- SkImageDecoder::Peeker* peeker =
- (SkImageDecoder::Peeker*)png_get_user_chunk_ptr(png_ptr);
- // peek() returning true means continue decoding
- return peeker->peek((const char*)chunk->name, chunk->data, chunk->size) ?
- 1 : -1;
-}
-
-static void sk_error_fn(png_structp png_ptr, png_const_charp msg) {
-#if 0
- SkDebugf("------ png error %s\n", msg);
-#endif
- longjmp(png_jmpbuf(png_ptr), 1);
-}
-
-static void skip_src_rows(png_structp png_ptr, uint8_t storage[], int count) {
- for (int i = 0; i < count; i++) {
- uint8_t* tmp = storage;
- png_read_rows(png_ptr, &tmp, png_bytepp_NULL, 1);
- }
-}
-
-static bool pos_le(int value, int max) {
- return value > 0 && value <= max;
-}
-
-static bool substituteTranspColor(SkBitmap* bm, SkPMColor match) {
- SkASSERT(bm->config() == SkBitmap::kARGB_8888_Config);
-
- bool reallyHasAlpha = false;
-
- for (int y = bm->height() - 1; y >= 0; --y) {
- SkPMColor* p = bm->getAddr32(0, y);
- for (int x = bm->width() - 1; x >= 0; --x) {
- if (match == *p) {
- *p = 0;
- reallyHasAlpha = true;
- }
- p += 1;
- }
- }
- return reallyHasAlpha;
-}
-
-bool SkPNGImageDecoder::onDecode(SkStream* sk_stream, SkBitmap* decodedBitmap,
- SkBitmap::Config prefConfig, Mode mode) {
-// SkAutoTrace apr("SkPNGImageDecoder::onDecode");
-
- /* Create and initialize the png_struct with the desired error handler
- * functions. If you want to use the default stderr and longjump method,
- * you can supply NULL for the last three parameters. We also supply the
- * the compiler header file version, so that we know if the application
- * was compiled with a compatible version of the library. */
- png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
- NULL, sk_error_fn, NULL);
- // png_voidp user_error_ptr, user_error_fn, user_warning_fn);
- if (png_ptr == NULL) {
- return false;
- }
-
- /* Allocate/initialize the memory for image information. */
- png_infop info_ptr = png_create_info_struct(png_ptr);
- if (info_ptr == NULL) {
- png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL);
- return false;
- }
-
- PNGAutoClean autoClean(png_ptr, info_ptr);
-
- /* Set error handling if you are using the setjmp/longjmp method (this is
- * the normal method of doing things with libpng). REQUIRED unless you
- * set up your own error handlers in the png_create_read_struct() earlier.
- */
- if (setjmp(png_jmpbuf(png_ptr))) {
- return false;
- }
-
- /* If you are using replacement read functions, instead of calling
- * png_init_io() here you would call:
- */
- png_set_read_fn(png_ptr, (void *)sk_stream, sk_read_fn);
- /* where user_io_ptr is a structure you want available to the callbacks */
- /* If we have already read some of the signature */
-// png_set_sig_bytes(png_ptr, 0 /* sig_read */ );
-
- // hookup our peeker so we can see any user-chunks the caller may be interested in
- png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_ALWAYS, (png_byte*)"", 0);
- if (this->getPeeker()) {
- png_set_read_user_chunk_fn(png_ptr, (png_voidp)this->getPeeker(), sk_read_user_chunk);
- }
-
- /* The call to png_read_info() gives us all of the information from the
- * PNG file before the first IDAT (image data chunk). */
- png_read_info(png_ptr, info_ptr);
- png_uint_32 origWidth, origHeight;
- int bit_depth, color_type, interlace_type;
- png_get_IHDR(png_ptr, info_ptr, &origWidth, &origHeight, &bit_depth, &color_type,
- &interlace_type, int_p_NULL, int_p_NULL);
-
- /* tell libpng to strip 16 bit/color files down to 8 bits/color */
- if (bit_depth == 16) {
- png_set_strip_16(png_ptr);
- }
- /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single
- * byte into separate bytes (useful for paletted and grayscale images). */
- if (bit_depth < 8) {
- png_set_packing(png_ptr);
- }
- /* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */
- if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
- png_set_gray_1_2_4_to_8(png_ptr);
- }
-
- /* Make a grayscale image into RGB. */
- if (color_type == PNG_COLOR_TYPE_GRAY ||
- color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
- png_set_gray_to_rgb(png_ptr);
- }
-
- SkBitmap::Config config;
- bool hasAlpha = false;
- bool doDither = this->getDitherImage();
- SkPMColor theTranspColor = 0; // 0 tells us not to try to match
-
- // check for sBIT chunk data, in case we should disable dithering because
- // our data is not truely 8bits per component
- if (doDither) {
-#if 0
- SkDebugf("----- sBIT %d %d %d %d\n", info_ptr->sig_bit.red,
- info_ptr->sig_bit.green, info_ptr->sig_bit.blue,
- info_ptr->sig_bit.alpha);
-#endif
- // 0 seems to indicate no information available
- if (pos_le(info_ptr->sig_bit.red, SK_R16_BITS) &&
- pos_le(info_ptr->sig_bit.green, SK_G16_BITS) &&
- pos_le(info_ptr->sig_bit.blue, SK_B16_BITS)) {
- doDither = false;
- }
- }
-
- if (color_type == PNG_COLOR_TYPE_PALETTE) {
- config = SkBitmap::kIndex8_Config; // defer sniffing for hasAlpha
- } else {
- png_color_16p transpColor = NULL;
- int numTransp = 0;
-
- png_get_tRNS(png_ptr, info_ptr, NULL, &numTransp, &transpColor);
-
- bool valid = png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS);
-
- if (valid && numTransp == 1 && transpColor != NULL) {
- /* Compute our transparent color, which we'll match against later.
- We don't really handle 16bit components properly here, since we
- do our compare *after* the values have been knocked down to 8bit
- which means we will find more matches than we should. The real
- fix seems to be to see the actual 16bit components, do the
- compare, and then knock it down to 8bits ourselves.
- */
- if (color_type & PNG_COLOR_MASK_COLOR) {
- if (16 == bit_depth) {
- theTranspColor = SkPackARGB32(0xFF, transpColor->red >> 8,
- transpColor->green >> 8, transpColor->blue >> 8);
- } else {
- theTranspColor = SkPackARGB32(0xFF, transpColor->red,
- transpColor->green, transpColor->blue);
- }
- } else { // gray
- if (16 == bit_depth) {
- theTranspColor = SkPackARGB32(0xFF, transpColor->gray >> 8,
- transpColor->gray >> 8, transpColor->gray >> 8);
- } else {
- theTranspColor = SkPackARGB32(0xFF, transpColor->gray,
- transpColor->gray, transpColor->gray);
- }
- }
- }
-
- if (valid ||
- PNG_COLOR_TYPE_RGB_ALPHA == color_type ||
- PNG_COLOR_TYPE_GRAY_ALPHA == color_type) {
- hasAlpha = true;
- config = SkBitmap::kARGB_8888_Config;
- } else { // we get to choose the config
- config = prefConfig;
- if (config == SkBitmap::kNo_Config) {
- config = SkImageDecoder::GetDeviceConfig();
- }
- if (config != SkBitmap::kRGB_565_Config &&
- config != SkBitmap::kARGB_4444_Config) {
- config = SkBitmap::kARGB_8888_Config;
- }
- }
- }
-
- if (!this->chooseFromOneChoice(config, origWidth, origHeight)) {
- return false;
- }
-
- const int sampleSize = this->getSampleSize();
- SkScaledBitmapSampler sampler(origWidth, origHeight, sampleSize);
-
- decodedBitmap->setConfig(config, sampler.scaledWidth(),
- sampler.scaledHeight(), 0);
- if (SkImageDecoder::kDecodeBounds_Mode == mode) {
- return true;
- }
-
- // from here down we are concerned with colortables and pixels
-
- // we track if we actually see a non-opaque pixels, since sometimes a PNG sets its colortype
- // to |= PNG_COLOR_MASK_ALPHA, but all of its pixels are in fact opaque. We care, since we
- // draw lots faster if we can flag the bitmap has being opaque
- bool reallyHasAlpha = false;
-
- SkColorTable* colorTable = NULL;
-
- if (color_type == PNG_COLOR_TYPE_PALETTE) {
- int num_palette;
- png_colorp palette;
- png_bytep trans;
- int num_trans;
-
- png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette);
-
- /* BUGGY IMAGE WORKAROUND
-
- We hit some images (e.g. fruit_.png) who contain bytes that are == colortable_count
- which is a problem since we use the byte as an index. To work around this we grow
- the colortable by 1 (if its < 256) and duplicate the last color into that slot.
- */
- int colorCount = num_palette + (num_palette < 256);
-
- colorTable = SkNEW_ARGS(SkColorTable, (colorCount));
-
- SkPMColor* colorPtr = colorTable->lockColors();
- if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
- png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, NULL);
- hasAlpha = (num_trans > 0);
- } else {
- num_trans = 0;
- colorTable->setFlags(colorTable->getFlags() | SkColorTable::kColorsAreOpaque_Flag);
- }
- // check for bad images that might make us crash
- if (num_trans > num_palette) {
- num_trans = num_palette;
- }
-
- int index = 0;
- int transLessThanFF = 0;
-
- for (; index < num_trans; index++) {
- transLessThanFF |= (int)*trans - 0xFF;
- *colorPtr++ = SkPreMultiplyARGB(*trans++, palette->red, palette->green, palette->blue);
- palette++;
- }
- reallyHasAlpha |= (transLessThanFF < 0);
-
- for (; index < num_palette; index++) {
- *colorPtr++ = SkPackARGB32(0xFF, palette->red, palette->green, palette->blue);
- palette++;
- }
-
- // see BUGGY IMAGE WORKAROUND comment above
- if (num_palette < 256) {
- *colorPtr = colorPtr[-1];
- }
- colorTable->unlockColors(true);
- }
-
- SkAutoUnref aur(colorTable);
-
- if (!this->allocPixelRef(decodedBitmap, colorTable)) {
- return false;
- }
-
- SkAutoLockPixels alp(*decodedBitmap);
-
- /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
-// if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
-// ; // png_set_swap_alpha(png_ptr);
-
- /* swap bytes of 16 bit files to least significant byte first */
- // png_set_swap(png_ptr);
-
- /* Add filler (or alpha) byte (before/after each RGB triplet) */
- if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_GRAY) {
- png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
- }
-
- /* Turn on interlace handling. REQUIRED if you are not using
- * png_read_image(). To see how to handle interlacing passes,
- * see the png_read_row() method below:
- */
- const int number_passes = interlace_type != PNG_INTERLACE_NONE ?
- png_set_interlace_handling(png_ptr) : 1;
-
- /* Optional call to gamma correct and add the background to the palette
- * and update info structure. REQUIRED if you are expecting libpng to
- * update the palette for you (ie you selected such a transform above).
- */
- png_read_update_info(png_ptr, info_ptr);
-
- if (SkBitmap::kIndex8_Config == config && 1 == sampleSize) {
- for (int i = 0; i < number_passes; i++) {
- for (png_uint_32 y = 0; y < origHeight; y++) {
- uint8_t* bmRow = decodedBitmap->getAddr8(0, y);
- png_read_rows(png_ptr, &bmRow, png_bytepp_NULL, 1);
- }
- }
- } else {
- SkScaledBitmapSampler::SrcConfig sc;
- int srcBytesPerPixel = 4;
-
- if (SkBitmap::kIndex8_Config == config) {
- sc = SkScaledBitmapSampler::kIndex;
- srcBytesPerPixel = 1;
- } else if (hasAlpha) {
- sc = SkScaledBitmapSampler::kRGBA;
- } else {
- sc = SkScaledBitmapSampler::kRGBX;
- }
-
- SkAutoMalloc storage(origWidth * srcBytesPerPixel);
- const int height = decodedBitmap->height();
-
- for (int i = 0; i < number_passes; i++) {
- if (!sampler.begin(decodedBitmap, sc, doDither)) {
- return false;
- }
-
- uint8_t* srcRow = (uint8_t*)storage.get();
- skip_src_rows(png_ptr, srcRow, sampler.srcY0());
-
- for (int y = 0; y < height; y++) {
- uint8_t* tmp = srcRow;
- png_read_rows(png_ptr, &tmp, png_bytepp_NULL, 1);
- reallyHasAlpha |= sampler.next(srcRow);
- if (y < height - 1) {
- skip_src_rows(png_ptr, srcRow, sampler.srcDY() - 1);
- }
- }
-
- // skip the rest of the rows (if any)
- png_uint_32 read = (height - 1) * sampler.srcDY() +
- sampler.srcY0() + 1;
- SkASSERT(read <= origHeight);
- skip_src_rows(png_ptr, srcRow, origHeight - read);
- }
-
- if (hasAlpha && !reallyHasAlpha) {
-#if 0
- SkDEBUGF(("Image doesn't really have alpha [%d %d]\n",
- origWidth, origHeight));
-#endif
- }
- }
-
- /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
- png_read_end(png_ptr, info_ptr);
-
- if (0 != theTranspColor) {
- reallyHasAlpha |= substituteTranspColor(decodedBitmap, theTranspColor);
- }
- decodedBitmap->setIsOpaque(!reallyHasAlpha);
- return true;
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-#ifdef SK_SUPPORT_IMAGE_ENCODE
-
-#include "SkColorPriv.h"
-#include "SkUnPreMultiply.h"
-
-static void sk_write_fn(png_structp png_ptr, png_bytep data, png_size_t len) {
- SkWStream* sk_stream = (SkWStream*)png_ptr->io_ptr;
- if (!sk_stream->write(data, len)) {
- png_error(png_ptr, "sk_write_fn Error!");
- }
-}
-
-typedef void (*transform_scanline_proc)(const char* SK_RESTRICT src,
- int width, char* SK_RESTRICT dst);
-
-static void transform_scanline_565(const char* SK_RESTRICT src, int width,
- char* SK_RESTRICT dst) {
- const uint16_t* SK_RESTRICT srcP = (const uint16_t*)src;
- for (int i = 0; i < width; i++) {
- unsigned c = *srcP++;
- *dst++ = SkPacked16ToR32(c);
- *dst++ = SkPacked16ToG32(c);
- *dst++ = SkPacked16ToB32(c);
- }
-}
-
-static void transform_scanline_888(const char* SK_RESTRICT src, int width,
- char* SK_RESTRICT dst) {
- const SkPMColor* SK_RESTRICT srcP = (const SkPMColor*)src;
- for (int i = 0; i < width; i++) {
- SkPMColor c = *srcP++;
- *dst++ = SkGetPackedR32(c);
- *dst++ = SkGetPackedG32(c);
- *dst++ = SkGetPackedB32(c);
- }
-}
-
-static void transform_scanline_444(const char* SK_RESTRICT src, int width,
- char* SK_RESTRICT dst) {
- const SkPMColor16* SK_RESTRICT srcP = (const SkPMColor16*)src;
- for (int i = 0; i < width; i++) {
- SkPMColor16 c = *srcP++;
- *dst++ = SkPacked4444ToR32(c);
- *dst++ = SkPacked4444ToG32(c);
- *dst++ = SkPacked4444ToB32(c);
- }
-}
-
-static void transform_scanline_8888(const char* SK_RESTRICT src, int width,
- char* SK_RESTRICT dst) {
- const SkPMColor* SK_RESTRICT srcP = (const SkPMColor*)src;
- const SkUnPreMultiply::Scale* SK_RESTRICT table =
- SkUnPreMultiply::GetScaleTable();
-
- for (int i = 0; i < width; i++) {
- SkPMColor c = *srcP++;
- unsigned a = SkGetPackedA32(c);
- unsigned r = SkGetPackedR32(c);
- unsigned g = SkGetPackedG32(c);
- unsigned b = SkGetPackedB32(c);
-
- if (0 != a && 255 != a) {
- SkUnPreMultiply::Scale scale = table[a];
- r = SkUnPreMultiply::ApplyScale(scale, r);
- g = SkUnPreMultiply::ApplyScale(scale, g);
- b = SkUnPreMultiply::ApplyScale(scale, b);
- }
- *dst++ = r;
- *dst++ = g;
- *dst++ = b;
- *dst++ = a;
- }
-}
-
-static void transform_scanline_4444(const char* SK_RESTRICT src, int width,
- char* SK_RESTRICT dst) {
- const SkPMColor16* SK_RESTRICT srcP = (const SkPMColor16*)src;
- const SkUnPreMultiply::Scale* SK_RESTRICT table =
- SkUnPreMultiply::GetScaleTable();
-
- for (int i = 0; i < width; i++) {
- SkPMColor16 c = *srcP++;
- unsigned a = SkPacked4444ToA32(c);
- unsigned r = SkPacked4444ToR32(c);
- unsigned g = SkPacked4444ToG32(c);
- unsigned b = SkPacked4444ToB32(c);
-
- if (0 != a && 255 != a) {
- SkUnPreMultiply::Scale scale = table[a];
- r = SkUnPreMultiply::ApplyScale(scale, r);
- g = SkUnPreMultiply::ApplyScale(scale, g);
- b = SkUnPreMultiply::ApplyScale(scale, b);
- }
- *dst++ = r;
- *dst++ = g;
- *dst++ = b;
- *dst++ = a;
- }
-}
-
-static void transform_scanline_index8(const char* SK_RESTRICT src, int width,
- char* SK_RESTRICT dst) {
- memcpy(dst, src, width);
-}
-
-static transform_scanline_proc choose_proc(SkBitmap::Config config,
- bool hasAlpha) {
- // we don't care about search on alpha if we're kIndex8, since only the
- // colortable packing cares about that distinction, not the pixels
- if (SkBitmap::kIndex8_Config == config) {
- hasAlpha = false; // we store false in the table entries for kIndex8
- }
-
- static const struct {
- SkBitmap::Config fConfig;
- bool fHasAlpha;
- transform_scanline_proc fProc;
- } gMap[] = {
- { SkBitmap::kRGB_565_Config, false, transform_scanline_565 },
- { SkBitmap::kARGB_8888_Config, false, transform_scanline_888 },
- { SkBitmap::kARGB_8888_Config, true, transform_scanline_8888 },
- { SkBitmap::kARGB_4444_Config, false, transform_scanline_444 },
- { SkBitmap::kARGB_4444_Config, true, transform_scanline_4444 },
- { SkBitmap::kIndex8_Config, false, transform_scanline_index8 },
- };
-
- for (int i = SK_ARRAY_COUNT(gMap) - 1; i >= 0; --i) {
- if (gMap[i].fConfig == config && gMap[i].fHasAlpha == hasAlpha) {
- return gMap[i].fProc;
- }
- }
- sk_throw();
- return NULL;
-}
-
-// return the minimum legal bitdepth (by png standards) for this many colortable
-// entries. SkBitmap always stores in 8bits per pixel, but for colorcount <= 16,
-// we can use fewer bits per in png
-static int computeBitDepth(int colorCount) {
-#if 0
- int bits = SkNextLog2(colorCount);
- SkASSERT(bits >= 1 && bits <= 8);
- // now we need bits itself to be a power of 2 (e.g. 1, 2, 4, 8)
- return SkNextPow2(bits);
-#else
- // for the moment, we don't know how to pack bitdepth < 8
- return 8;
-#endif
-}
-
-/* Pack palette[] with the corresponding colors, and if hasAlpha is true, also
- pack trans[] and return the number of trans[] entries written. If hasAlpha
- is false, the return value will always be 0.
-
- Note: this routine takes care of unpremultiplying the RGB values when we
- have alpha in the colortable, since png doesn't support premul colors
-*/
-static int pack_palette(SkColorTable* ctable, png_color* SK_RESTRICT palette,
- png_byte* SK_RESTRICT trans, bool hasAlpha) {
- SkAutoLockColors alc(ctable);
- const SkPMColor* SK_RESTRICT colors = alc.colors();
- const int ctCount = ctable->count();
- int i, num_trans = 0;
-
- if (hasAlpha) {
- /* first see if we have some number of fully opaque at the end of the
- ctable. PNG allows num_trans < num_palette, but all of the trans
- entries must come first in the palette. If I was smarter, I'd
- reorder the indices and ctable so that all non-opaque colors came
- first in the palette. But, since that would slow down the encode,
- I'm leaving the indices and ctable order as is, and just looking
- at the tail of the ctable for opaqueness.
- */
- num_trans = ctCount;
- for (i = ctCount - 1; i >= 0; --i) {
- if (SkGetPackedA32(colors[i]) != 0xFF) {
- break;
- }
- num_trans -= 1;
- }
-
- const SkUnPreMultiply::Scale* SK_RESTRICT table =
- SkUnPreMultiply::GetScaleTable();
-
- for (i = 0; i < num_trans; i++) {
- const SkPMColor c = *colors++;
- const unsigned a = SkGetPackedA32(c);
- const SkUnPreMultiply::Scale s = table[a];
- trans[i] = a;
- palette[i].red = SkUnPreMultiply::ApplyScale(s, SkGetPackedR32(c));
- palette[i].green = SkUnPreMultiply::ApplyScale(s,SkGetPackedG32(c));
- palette[i].blue = SkUnPreMultiply::ApplyScale(s, SkGetPackedB32(c));
- }
- // now fall out of this if-block to use common code for the trailing
- // opaque entries
- }
-
- // these (remaining) entries are opaque
- for (i = num_trans; i < ctCount; i++) {
- SkPMColor c = *colors++;
- palette[i].red = SkGetPackedR32(c);
- palette[i].green = SkGetPackedG32(c);
- palette[i].blue = SkGetPackedB32(c);
- }
- return num_trans;
-}
-
-class SkPNGImageEncoder : public SkImageEncoder {
-protected:
- virtual bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality);
-};
-
-bool SkPNGImageEncoder::onEncode(SkWStream* stream, const SkBitmap& bitmap,
- int /*quality*/) {
- SkBitmap::Config config = bitmap.getConfig();
-
- const bool hasAlpha = !bitmap.isOpaque();
- int colorType = PNG_COLOR_MASK_COLOR;
- int bitDepth = 8; // default for color
- png_color_8 sig_bit;
-
- switch (config) {
- case SkBitmap::kIndex8_Config:
- colorType |= PNG_COLOR_MASK_PALETTE;
- // fall through to the ARGB_8888 case
- case SkBitmap::kARGB_8888_Config:
- sig_bit.red = 8;
- sig_bit.green = 8;
- sig_bit.blue = 8;
- sig_bit.alpha = 8;
- break;
- case SkBitmap::kARGB_4444_Config:
- sig_bit.red = 4;
- sig_bit.green = 4;
- sig_bit.blue = 4;
- sig_bit.alpha = 4;
- break;
- case SkBitmap::kRGB_565_Config:
- sig_bit.red = 5;
- sig_bit.green = 6;
- sig_bit.blue = 5;
- sig_bit.alpha = 0;
- break;
- default:
- return false;
- }
-
- if (hasAlpha) {
- // don't specify alpha if we're a palette, even if our ctable has alpha
- if (!(colorType & PNG_COLOR_MASK_PALETTE)) {
- colorType |= PNG_COLOR_MASK_ALPHA;
- }
- } else {
- sig_bit.alpha = 0;
- }
-
- SkAutoLockPixels alp(bitmap);
- // readyToDraw checks for pixels (and colortable if that is required)
- if (!bitmap.readyToDraw()) {
- return false;
- }
-
- // we must do this after we have locked the pixels
- SkColorTable* ctable = bitmap.getColorTable();
- if (NULL != ctable) {
- if (ctable->count() == 0) {
- return false;
- }
- // check if we can store in fewer than 8 bits
- bitDepth = computeBitDepth(ctable->count());
- }
-
- png_structp png_ptr;
- png_infop info_ptr;
-
- png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, sk_error_fn,
- NULL);
- if (NULL == png_ptr) {
- return false;
- }
-
- info_ptr = png_create_info_struct(png_ptr);
- if (NULL == info_ptr) {
- png_destroy_write_struct(&png_ptr, png_infopp_NULL);
- return false;
- }
-
- /* Set error handling. REQUIRED if you aren't supplying your own
- * error handling functions in the png_create_write_struct() call.
- */
- if (setjmp(png_jmpbuf(png_ptr))) {
- png_destroy_write_struct(&png_ptr, &info_ptr);
- return false;
- }
-
- png_set_write_fn(png_ptr, (void*)stream, sk_write_fn, png_flush_ptr_NULL);
-
- /* Set the image information here. Width and height are up to 2^31,
- * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on
- * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY,
- * PNG_COLOR_TYPE_GRAY_ALPHA, PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB,
- * or PNG_COLOR_TYPE_RGB_ALPHA. interlace is either PNG_INTERLACE_NONE or
- * PNG_INTERLACE_ADAM7, and the compression_type and filter_type MUST
- * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED
- */
-
- png_set_IHDR(png_ptr, info_ptr, bitmap.width(), bitmap.height(),
- bitDepth, colorType,
- PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
- PNG_FILTER_TYPE_BASE);
-
-#if 0 // need to support this some day
- /* set the palette if there is one. REQUIRED for indexed-color images */
- palette = (png_colorp)png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH
- * png_sizeof (png_color));
- /* ... set palette colors ... */
- png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH);
- /* You must not free palette here, because png_set_PLTE only makes a link to
- the palette that you malloced. Wait until you are about to destroy
- the png structure. */
-#endif
-
- png_set_sBIT(png_ptr, info_ptr, &sig_bit);
- png_write_info(png_ptr, info_ptr);
-
- const char* srcImage = (const char*)bitmap.getPixels();
- SkAutoSMalloc<1024> rowStorage(bitmap.width() << 2);
- char* storage = (char*)rowStorage.get();
- transform_scanline_proc proc = choose_proc(config, hasAlpha);
-
- for (int y = 0; y < bitmap.height(); y++) {
- png_bytep row_ptr = (png_bytep)storage;
- proc(srcImage, bitmap.width(), storage);
- png_write_rows(png_ptr, &row_ptr, 1);
- srcImage += bitmap.rowBytes();
- }
-
- png_write_end(png_ptr, info_ptr);
-
- /* clean up after the write, and free any memory allocated */
- png_destroy_write_struct(&png_ptr, &info_ptr);
- return true;
-}
-
-SkImageEncoder* SkImageEncoder_PNG_Factory();
-SkImageEncoder* SkImageEncoder_PNG_Factory() {
- return SkNEW(SkPNGImageEncoder);
-}
-
-#endif /* SK_SUPPORT_IMAGE_ENCODE */
« no previous file with comments | « skia/images/SkImageDecoder_libjpeg.cpp ('k') | skia/images/SkImageDecoder_libpvjpeg.cpp » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698