SkPDF: images support 32-but-not-N32 colortype

src/pdf/SkPDFBitmap.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkColorPriv.h"
 #include "SkData.h"
 #include "SkDeflate.h"
@@ skipping 41 matching lines @@
 // write a single byte to a stream n times.
 static void fill_stream(SkWStream* out, char value, size_t n) {
     char buffer[4096];
     memset(buffer, value, sizeof(buffer));
     for (size_t i = 0; i < n / sizeof(buffer); ++i) {
         out->write(buffer, sizeof(buffer));
     }
     out->write(buffer, n % sizeof(buffer));
 }
 
+// TODO(reed@): Decide if these five functions belong in SkColorPriv.h
+static bool SkIsBGRA(SkColorType ct) {
+    SkASSERT(kBGRA_8888_SkColorType == ct || kRGBA_8888_SkColorType == ct);
+    return kBGRA_8888_SkColorType == ct;
+}
+
+// Interpret value as the given 4-byte SkColorType (BGRA_8888 or
+// RGBA_8888) and return the appropriate component.  Each component
+// should be interpreted according to the associated SkAlphaType and
+// SkColorProfileType.
+static U8CPU SkGetA32Component(uint32_t value, SkColorType ct) {
+    return (value >> (SkIsBGRA(ct) ? SK_BGRA_A32_SHIFT : SK_RGBA_A32_SHIFT)) & 0xFF;
+}
+static U8CPU SkGetR32Component(uint32_t value, SkColorType ct) {
+    return (value >> (SkIsBGRA(ct) ? SK_BGRA_R32_SHIFT : SK_RGBA_R32_SHIFT)) & 0xFF;
+}
+static U8CPU SkGetG32Component(uint32_t value, SkColorType ct) {
+    return (value >> (SkIsBGRA(ct) ? SK_BGRA_G32_SHIFT : SK_RGBA_G32_SHIFT)) & 0xFF;
+}
+static U8CPU SkGetB32Component(uint32_t value, SkColorType ct) {
+    return (value >> (SkIsBGRA(ct) ? SK_BGRA_B32_SHIFT : SK_RGBA_B32_SHIFT)) & 0xFF;
+}
+
+
 // unpremultiply and extract R, G, B components.
-static void pmcolor_to_rgb24(SkPMColor pmColor, uint8_t* rgb) {
-    uint32_t s = SkUnPreMultiply::GetScale(SkGetPackedA32(pmColor));
-    rgb[0] = SkUnPreMultiply::ApplyScale(s, SkGetPackedR32(pmColor));
-    rgb[1] = SkUnPreMultiply::ApplyScale(s, SkGetPackedG32(pmColor));
-    rgb[2] = SkUnPreMultiply::ApplyScale(s, SkGetPackedB32(pmColor));
+static void pmcolor_to_rgb24(uint32_t color, uint8_t* rgb, SkColorType ct) {
+    uint32_t s = SkUnPreMultiply::GetScale(SkGetA32Component(color, ct));
+    rgb[0] = SkUnPreMultiply::ApplyScale(s, SkGetR32Component(color, ct));
+    rgb[1] = SkUnPreMultiply::ApplyScale(s, SkGetG32Component(color, ct));
+    rgb[2] = SkUnPreMultiply::ApplyScale(s, SkGetB32Component(color, ct));
 }
 
 /* It is necessary to average the color component of transparent
    pixels with their surrounding neighbors since the PDF renderer may
    separately re-sample the alpha and color channels when the image is
    not displayed at its native resolution. Since an alpha of zero
    gives no information about the color component, the pathological
    case is a white image with sharp transparency bounds - the color
    channel goes to black, and the should-be-transparent pixels are
    rendered as grey because of the separate soft mask and color
    resizing. e.g.: gm/bitmappremul.cpp */
 static void get_neighbor_avg_color(const SkBitmap& bm,
                                    int xOrig,
                                    int yOrig,
-                                   uint8_t rgb[3]) {
-    SkASSERT(kN32_SkColorType == bm.colorType());
+                                   uint8_t rgb[3],
+                                   SkColorType ct) {
     unsigned a = 0, r = 0, g = 0, b = 0;
     // Clamp the range to the edge of the bitmap.
     int ymin = SkTMax(0, yOrig - 1);
     int ymax = SkTMin(yOrig + 1, bm.height() - 1);
     int xmin = SkTMax(0, xOrig - 1);
     int xmax = SkTMin(xOrig + 1, bm.width() - 1);
     for (int y = ymin; y <= ymax; ++y) {
-        SkPMColor* scanline = bm.getAddr32(0, y);
+        uint32_t* scanline = bm.getAddr32(0, y);
         for (int x = xmin; x <= xmax; ++x) {
-            SkPMColor pmColor = scanline[x];
-            a += SkGetPackedA32(pmColor);
-            r += SkGetPackedR32(pmColor);
-            g += SkGetPackedG32(pmColor);
-            b += SkGetPackedB32(pmColor);
+            uint32_t color = scanline[x];
+            a += SkGetA32Component(color, ct);
+            r += SkGetR32Component(color, ct);
+            g += SkGetG32Component(color, ct);
+            b += SkGetB32Component(color, ct);
         }
     }
     if (a > 0) {
         rgb[0] = SkToU8(255 * r / a);
         rgb[1] = SkToU8(255 * g / a);
         rgb[2] = SkToU8(255 * b / a);
     } else {
         rgb[0] = rgb[1] = rgb[2] = 0;
     }
 }
 
 static size_t pixel_count(const SkBitmap& bm) {
     return SkToSizeT(bm.width()) * SkToSizeT(bm.height());
 }
 
 static const SkBitmap& not4444(const SkBitmap& input, SkBitmap* copy) {
     if (input.colorType() != kARGB_4444_SkColorType) {
         return input;
     }
     // ARGB_4444 is rarely used, so we can do a wasteful tmp copy.
     SkAssertResult(input.copyTo(copy, kN32_SkColorType));
     copy->setImmutable();
     return *copy;
 }
 
 static size_t pdf_color_component_count(SkColorType ct) {
     switch (ct) {
-        case kN32_SkColorType:
         case kRGB_565_SkColorType:
         case kARGB_4444_SkColorType:
+        case kRGBA_8888_SkColorType:
+        case kBGRA_8888_SkColorType:
             return 3;
         case kAlpha_8_SkColorType:
         case kIndex_8_SkColorType:
         case kGray_8_SkColorType:
             return 1;
         case kUnknown_SkColorType:
         default:
             SkDEBUGFAIL("unexpected color type");
             return 0;
     }
 }
 
 static void bitmap_to_pdf_pixels(const SkBitmap& bitmap, SkWStream* out) {
     if (!bitmap.getPixels()) {
         size_t size = pixel_count(bitmap) *
                       pdf_color_component_count(bitmap.colorType());
         fill_stream(out, '\x00', size);
         return;
     }
     SkBitmap copy;
     const SkBitmap& bm = not4444(bitmap, &copy);
     SkAutoLockPixels autoLockPixels(bm);
-    switch (bm.colorType()) {
-        case kN32_SkColorType: {
-            SkASSERT(3 == pdf_color_component_count(bitmap.colorType()));
+    SkColorType colorType = bm.colorType();
+    switch (colorType) {
+        case kRGBA_8888_SkColorType:
+        case kBGRA_8888_SkColorType: {
+            SkASSERT(3 == pdf_color_component_count(colorType));
             SkAutoTMalloc<uint8_t> scanline(3 * bm.width());
             for (int y = 0; y < bm.height(); ++y) {
-                const SkPMColor* src = bm.getAddr32(0, y);
+                const uint32_t* src = bm.getAddr32(0, y);
                 uint8_t* dst = scanline.get();
                 for (int x = 0; x < bm.width(); ++x) {
-                    SkPMColor color = *src++;
-                    U8CPU alpha = SkGetPackedA32(color);
+                    uint32_t color = *src++;
+                    U8CPU alpha = SkGetA32Component(color, colorType);
                     if (alpha != SK_AlphaTRANSPARENT) {
-                        pmcolor_to_rgb24(color, dst);
+                        pmcolor_to_rgb24(color, dst, colorType);
                     } else {
-                        get_neighbor_avg_color(bm, x, y, dst);
+                        get_neighbor_avg_color(bm, x, y, dst, colorType);
                     }
                     dst += 3;
                 }
                 out->write(scanline.get(), 3 * bm.width());
             }
             return;
         }
         case kRGB_565_SkColorType: {
-            SkASSERT(3 == pdf_color_component_count(bitmap.colorType()));
+            SkASSERT(3 == pdf_color_component_count(colorType));
             SkAutoTMalloc<uint8_t> scanline(3 * bm.width());
             for (int y = 0; y < bm.height(); ++y) {
                 const uint16_t* src = bm.getAddr16(0, y);
                 uint8_t* dst = scanline.get();
                 for (int x = 0; x < bm.width(); ++x) {
                     U16CPU color565 = *src++;
                     *dst++ = SkPacked16ToR32(color565);
                     *dst++ = SkPacked16ToG32(color565);
                     *dst++ = SkPacked16ToB32(color565);
                 }
                 out->write(scanline.get(), 3 * bm.width());
             }
             return;
         }
         case kAlpha_8_SkColorType:
-            SkASSERT(1 == pdf_color_component_count(bitmap.colorType()));
+            SkASSERT(1 == pdf_color_component_count(colorType));
             fill_stream(out, '\x00', pixel_count(bm));
             return;
         case kGray_8_SkColorType:
         case kIndex_8_SkColorType:
-            SkASSERT(1 == pdf_color_component_count(bitmap.colorType()));
+            SkASSERT(1 == pdf_color_component_count(colorType));
             // these two formats need no transformation to serialize.
             for (int y = 0; y < bm.height(); ++y) {
                 out->write(bm.getAddr8(0, y), bm.width());
             }
             return;
         case kUnknown_SkColorType:
         case kARGB_4444_SkColorType:
         default:
             SkDEBUGFAIL("unexpected color type");
     }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 static void bitmap_alpha_to_a8(const SkBitmap& bitmap, SkWStream* out) {
     if (!bitmap.getPixels()) {
         fill_stream(out, '\xFF', pixel_count(bitmap));
         return;
     }
     SkBitmap copy;
     const SkBitmap& bm = not4444(bitmap, &copy);
     SkAutoLockPixels autoLockPixels(bm);
-    switch (bm.colorType()) {
-        case kN32_SkColorType: {
+    SkColorType colorType = bm.colorType();
+    switch (colorType) {
+        case kRGBA_8888_SkColorType:
+        case kBGRA_8888_SkColorType: {
             SkAutoTMalloc<uint8_t> scanline(bm.width());
             for (int y = 0; y < bm.height(); ++y) {
                 uint8_t* dst = scanline.get();
                 const SkPMColor* src = bm.getAddr32(0, y);
                 for (int x = 0; x < bm.width(); ++x) {
-                    *dst++ = SkGetPackedA32(*src++);
+                    *dst++ = SkGetA32Component(*src++, colorType);
                 }
                 out->write(scanline.get(), bm.width());
             }
             return;
         }
         case kAlpha_8_SkColorType:
             for (int y = 0; y < bm.height(); ++y) {
                 out->write(bm.getAddr8(0, y), bm.width());
             }
             return;
@@ skipping 39 matching lines @@
     }
     result->appendInt(table->count() - 1);  // maximum color index.
 
     // Potentially, this could be represented in fewer bytes with a stream.
     // Max size as a string is 1.5k.
     char tableArray[256 * 3];
     SkASSERT(3u * table->count() <= SK_ARRAY_COUNT(tableArray));
     uint8_t* tablePtr = reinterpret_cast<uint8_t*>(tableArray);
     const SkPMColor* colors = table->readColors();
     for (int i = 0; i < table->count(); i++) {
-        pmcolor_to_rgb24(colors[i], tablePtr);
+        pmcolor_to_rgb24(colors[i], tablePtr, kN32_SkColorType);
         tablePtr += 3;
     }
     SkString tableString(tableArray, 3 * table->count());
     result->appendString(tableString);
     return result;
 }
 
 static void emit_image_xobject(SkWStream* stream,
                                const SkImage* image,
                                bool alpha,
@@ skipping 150 matching lines @@
             return new PDFJpegBitmap(info.fSize, data, yuv);
         }
     }
     SkPDFObject* smask =
             image_compute_is_opaque(image) ? nullptr : new PDFAlphaBitmap(image);
     #ifdef SK_PDF_IMAGE_STATS
     gRegularImageObjects.fetch_add(1);
     #endif
     return new PDFDefaultBitmap(image, smask);
 }