implement readPixels and writePixels natively, w/o using the (deprecated)

tests/WritePixelsTest.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapDevice.h"
 #include "SkCanvas.h"
 #include "SkColorPriv.h"
@@ skipping 38 matching lines @@
         case 3:
             a = 0x00;
             break;
         case 4:
             a = 0x01;
             break;
     }
     return SkPremultiplyARGBInline(a, r, g, b);
 }
 
-static bool config8888IsPremul(SkCanvas::Config8888 config8888) {
-    switch (config8888) {
-        case SkCanvas::kNative_Premul_Config8888:
-        case SkCanvas::kBGRA_Premul_Config8888:
-        case SkCanvas::kRGBA_Premul_Config8888:
-            return true;
-        case SkCanvas::kNative_Unpremul_Config8888:
-        case SkCanvas::kBGRA_Unpremul_Config8888:
-        case SkCanvas::kRGBA_Unpremul_Config8888:
-            return false;
-        default:
-            SkASSERT(0);
-            return false;
-    }
-}
-
 // assumes any premu/.unpremul has been applied
-static uint32_t packConfig8888(SkCanvas::Config8888 config8888,
-                               U8CPU a, U8CPU r, U8CPU g, U8CPU b) {
+static uint32_t packColorType(SkColorType ct, U8CPU a, U8CPU r, U8CPU g, U8CPU b) {
     uint32_t r32;
     uint8_t* result = reinterpret_cast<uint8_t*>(&r32);
-    switch (config8888) {
-        case SkCanvas::kNative_Premul_Config8888:
-        case SkCanvas::kNative_Unpremul_Config8888:
-            r32 = SkPackARGB32NoCheck(a, r, g, b);
-            break;
-        case SkCanvas::kBGRA_Premul_Config8888:
-        case SkCanvas::kBGRA_Unpremul_Config8888:
+    switch (ct) {
+        case kBGRA_8888_SkColorType:
             result[0] = b;
             result[1] = g;
             result[2] = r;
             result[3] = a;
             break;
-        case SkCanvas::kRGBA_Premul_Config8888:
-        case SkCanvas::kRGBA_Unpremul_Config8888:
+        case kRGBA_8888_SkColorType:
             result[0] = r;
             result[1] = g;
             result[2] = b;
             result[3] = a;
             break;
         default:
             SkASSERT(0);
             return 0;
     }
     return r32;
 }
 
-static uint32_t getBitmapColor(int x, int y, int w, SkCanvas::Config8888 config8888) {
+static uint32_t getBitmapColor(int x, int y, int w, SkColorType ct, SkAlphaType at) {
     int n = y * w + x;
     U8CPU b = n & 0xff;
     U8CPU g = (n >> 8) & 0xff;
     U8CPU r = (n >> 16) & 0xff;
     U8CPU a = 0;
     switch ((x+y) % 5) {
         case 4:
             a = 0xff;
             break;
         case 3:
             a = 0x80;
             break;
         case 2:
             a = 0xCC;
             break;
         case 1:
             a = 0x01;
             break;
         case 0:
             a = 0x00;
             break;
     }
-    if (config8888IsPremul(config8888)) {
+    if (kPremul_SkAlphaType == at) {
         r = SkMulDiv255Ceiling(r, a);
         g = SkMulDiv255Ceiling(g, a);
         b = SkMulDiv255Ceiling(b, a);
     }
-    return packConfig8888(config8888, a, r, g , b);
+    return packColorType(ct, a, r, g , b);
 }
 
 static void fillCanvas(SkCanvas* canvas) {
     SkBitmap bmp;
     if (bmp.isNull()) {
         SkDEBUGCODE(bool alloc = ) bmp.allocN32Pixels(DEV_W, DEV_H);
         SkASSERT(alloc);
         for (int y = 0; y < DEV_H; ++y) {
             for (int x = 0; x < DEV_W; ++x) {
                 *bmp.getAddr32(x, y) = getCanvasColor(x, y);
             }
         }
     }
     canvas->save();
     canvas->setMatrix(SkMatrix::I());
     canvas->clipRect(DEV_RECT_S, SkRegion::kReplace_Op);
     SkPaint paint;
     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
     canvas->drawBitmap(bmp, 0, 0, &paint);
     canvas->restore();
 }
 
-static SkPMColor convertConfig8888ToPMColor(SkCanvas::Config8888 config8888,
-                                            uint32_t color,
-                                            bool* premul) {
-    const uint8_t* c = reinterpret_cast<uint8_t*>(&color);
-    U8CPU a,r,g,b;
-    *premul = false;
-    switch (config8888) {
-        case SkCanvas::kNative_Premul_Config8888:
-            return color;
-        case SkCanvas::kNative_Unpremul_Config8888:
-            *premul = true;
-            a = SkGetPackedA32(color);
-            r = SkGetPackedR32(color);
-            g = SkGetPackedG32(color);
-            b = SkGetPackedB32(color);
+/**
+ *  Lucky for us, alpha is always in the same spot (SK_A32_SHIFT), for both RGBA and BGRA.
+ *  Thus this routine doesn't need to know the exact colortype
+ */
+static uint32_t premul(uint32_t color) {
+    unsigned a = SkGetPackedA32(color);
+    // these next three are not necessarily r,g,b in that order, but they are r,g,b in some order.
+    unsigned c0 = SkGetPackedR32(color);
+    unsigned c1 = SkGetPackedG32(color);
+    unsigned c2 = SkGetPackedB32(color);
+    c0 = SkMulDiv255Ceiling(c0, a);
+    c1 = SkMulDiv255Ceiling(c1, a);
+    c2 = SkMulDiv255Ceiling(c2, a);
+    return SkPackARGB32NoCheck(a, c0, c1, c2);
+}
+
+static SkPMColor convert_to_PMColor(SkColorType ct, SkAlphaType at, uint32_t color) {
+    if (kUnpremul_SkAlphaType == at) {
+        color = premul(color);
+    }
+    switch (ct) {
+        case kRGBA_8888_SkColorType:
+            color = SkSwizzle_RGBA_to_PMColor(color);
             break;
-        case SkCanvas::kBGRA_Unpremul_Config8888:
-            *premul = true; // fallthru
-        case SkCanvas::kBGRA_Premul_Config8888:
-            a = static_cast<U8CPU>(c[3]);
-            r = static_cast<U8CPU>(c[2]);
-            g = static_cast<U8CPU>(c[1]);
-            b = static_cast<U8CPU>(c[0]);
-            break;
-        case SkCanvas::kRGBA_Unpremul_Config8888:
-            *premul = true; // fallthru
-        case SkCanvas::kRGBA_Premul_Config8888:
-            a = static_cast<U8CPU>(c[3]);
-            r = static_cast<U8CPU>(c[0]);
-            g = static_cast<U8CPU>(c[1]);
-            b = static_cast<U8CPU>(c[2]);
+        case kBGRA_8888_SkColorType:
+            color = SkSwizzle_BGRA_to_PMColor(color);
             break;
         default:
-            SkDEBUGFAIL("Unexpected Config8888");
-            return 0;
+            SkASSERT(0);
+            break;
     }
-    if (*premul) {
-        r = SkMulDiv255Ceiling(r, a);
-        g = SkMulDiv255Ceiling(g, a);
-        b = SkMulDiv255Ceiling(b, a);
-    }
-    return SkPackARGB32(a, r, g, b);
+    return color;
 }
 
 static bool checkPixel(SkPMColor a, SkPMColor b, bool didPremulConversion) {
     if (!didPremulConversion) {
         return a == b;
     }
     int32_t aA = static_cast<int32_t>(SkGetPackedA32(a));
     int32_t aR = static_cast<int32_t>(SkGetPackedR32(a));
     int32_t aG = static_cast<int32_t>(SkGetPackedG32(a));
     int32_t aB = SkGetPackedB32(a);
 
     int32_t bA = static_cast<int32_t>(SkGetPackedA32(b));
     int32_t bR = static_cast<int32_t>(SkGetPackedR32(b));
     int32_t bG = static_cast<int32_t>(SkGetPackedG32(b));
     int32_t bB = static_cast<int32_t>(SkGetPackedB32(b));
 
     return aA == bA &&
            SkAbs32(aR - bR) <= 1 &&
            SkAbs32(aG - bG) <= 1 &&
            SkAbs32(aB - bB) <= 1;
 }
 
-static bool checkWrite(skiatest::Reporter* reporter,
-                       SkCanvas* canvas,
-                       const SkBitmap& bitmap,
-                       int writeX, int writeY,
-                       SkCanvas::Config8888 config8888) {
-    SkBaseDevice* dev = canvas->getDevice();
-    if (!dev) {
+static bool checkWrite(skiatest::Reporter* reporter, SkCanvas* canvas, const SkBitmap& bitmap,
+                       int writeX, int writeY) {
+    SkImageInfo canvasInfo;
+    size_t canvasRowBytes;
+    const uint32_t* canvasPixels;
+
+    // Can't use canvas->peekPixels(), as we are trying to look at GPU pixels sometimes as well.
+    // At some point this will be unsupported, as we won't allow accessBitmap() to magically call
+    // readPixels for the client.
+    SkBitmap secretDevBitmap;
+    {
+        SkBaseDevice* dev = canvas->getDevice();
+        if (!dev) {
+            return false;
+        }
+        secretDevBitmap = dev->accessBitmap(false);
+    }
+    SkAutoLockPixels alp(secretDevBitmap);
+    canvasInfo = secretDevBitmap.info();
+    canvasRowBytes = secretDevBitmap.rowBytes();
+    canvasPixels = static_cast<const uint32_t*>(secretDevBitmap.getPixels());
+
+    if (NULL == canvasPixels) {
         return false;
     }
-    SkBitmap devBmp = dev->accessBitmap(false);
-    if (devBmp.width() != DEV_W ||
-        devBmp.height() != DEV_H ||
-        devBmp.config() != SkBitmap::kARGB_8888_Config ||
-        devBmp.isNull()) {
+
+    if (canvasInfo.width() != DEV_W ||
+        canvasInfo.height() != DEV_H ||
+        canvasInfo.colorType() != kPMColor_SkColorType) {
         return false;
     }
-    SkAutoLockPixels alp(devBmp);
 
-    intptr_t canvasPixels = reinterpret_cast<intptr_t>(devBmp.getPixels());
-    size_t canvasRowBytes = devBmp.rowBytes();
+    const SkImageInfo bmInfo = bitmap.info();
+
     SkIRect writeRect = SkIRect::MakeXYWH(writeX, writeY, bitmap.width(), bitmap.height());
     for (int cy = 0; cy < DEV_H; ++cy) {
-        const SkPMColor* canvasRow = reinterpret_cast<const SkPMColor*>(canvasPixels);
         for (int cx = 0; cx < DEV_W; ++cx) {
-            SkPMColor canvasPixel = canvasRow[cx];
+            SkPMColor canvasPixel = canvasPixels[cx];
             if (writeRect.contains(cx, cy)) {
                 int bx = cx - writeX;
                 int by = cy - writeY;
-                uint32_t bmpColor8888 = getBitmapColor(bx, by, bitmap.width(), config8888);
-                bool mul;
-                SkPMColor bmpPMColor = convertConfig8888ToPMColor(config8888, bmpColor8888, &mul);
-                bool check;
-                REPORTER_ASSERT(reporter, check = checkPixel(bmpPMColor, canvasPixel, mul));
+                uint32_t bmpColor8888 = getBitmapColor(bx, by, bitmap.width(),
+                                                       bmInfo.colorType(), bmInfo.alphaType());
+                bool mul = (kUnpremul_SkAlphaType == bmInfo.alphaType());
+                SkPMColor bmpPMColor = convert_to_PMColor(bmInfo.colorType(), bmInfo.alphaType(),
+                                                          bmpColor8888);
+                bool check = checkPixel(bmpPMColor, canvasPixel, mul);
+                REPORTER_ASSERT(reporter, check);
                 if (!check) {
                     return false;
                 }
             } else {
                 bool check;
                 SkPMColor testColor = getCanvasColor(cx, cy);
                 REPORTER_ASSERT(reporter, check = (canvasPixel == testColor));
                 if (!check) {
                     return false;
                 }
             }
         }
         if (cy != DEV_H -1) {
-            const char* pad = reinterpret_cast<const char*>(canvasPixels + 4 * DEV_W);
+            const char* pad = reinterpret_cast<const char*>(canvasPixels + DEV_W);
             for (size_t px = 0; px < canvasRowBytes - 4 * DEV_W; ++px) {
                 bool check;
                 REPORTER_ASSERT(reporter, check = (pad[px] == static_cast<char>(DEV_PAD)));
                 if (!check) {
                     return false;
                 }
             }
         }
-        canvasPixels += canvasRowBytes;
+        canvasPixels += canvasRowBytes/4;
     }
 
     return true;
 }
 
 enum DevType {
     kRaster_DevType,
 #if SK_SUPPORT_GPU
     kGpu_BottomLeft_DevType,
     kGpu_TopLeft_DevType,
@@ skipping 60 matching lines @@
             desc.fOrigin = kGpu_TopLeft_DevType == c.fDevType ?
                 kTopLeft_GrSurfaceOrigin : kBottomLeft_GrSurfaceOrigin;
             GrAutoScratchTexture ast(grCtx, desc, GrContext::kExact_ScratchTexMatch);
             SkAutoTUnref<GrTexture> tex(ast.detach());
             return new SkGpuDevice(grCtx, tex);
 #endif
     }
     return NULL;
 }
 
-static bool setupBitmap(SkBitmap* bitmap,
-                        SkCanvas::Config8888 config8888,
-                        int w, int h,
-                        bool tightRowBytes) {
-    size_t rowBytes = tightRowBytes ? 0 : 4 * w + 60;
-    SkImageInfo info = SkImageInfo::MakeN32Premul(w, h);
-    if (!allocRowBytes(bitmap, info, rowBytes)) {
+static bool setupBitmap(SkBitmap* bm, SkColorType ct, SkAlphaType at, int w, int h, int tightRB) {
+    size_t rowBytes = tightRB ? 0 : 4 * w + 60;
+    SkImageInfo info = SkImageInfo::Make(w, h, ct, at);
+    if (!allocRowBytes(bm, info, rowBytes)) {
         return false;
     }
-    SkAutoLockPixels alp(*bitmap);
-    intptr_t pixels = reinterpret_cast<intptr_t>(bitmap->getPixels());
+    SkAutoLockPixels alp(*bm);
     for (int y = 0; y < h; ++y) {
         for (int x = 0; x < w; ++x) {
-            uint32_t* pixel = reinterpret_cast<uint32_t*>(pixels + y * bitmap->rowBytes() + x * 4);
-            *pixel = getBitmapColor(x, y, w, config8888);
+            *bm->getAddr32(x, y) = getBitmapColor(x, y, w, ct, at);
         }
     }
     return true;
 }
 
 DEF_GPUTEST(WritePixels, reporter, factory) {
     SkCanvas canvas;
 
     const SkIRect testRects[] = {
         // entire thing
@@ skipping 63 matching lines @@
                 context = factory->get(type);
                 if (NULL == context) {
                     continue;
                 }
             }
 #endif
 
             SkAutoTUnref<SkBaseDevice> device(createDevice(gCanvasConfigs[i], context));
             SkCanvas canvas(device);
 
-            static const SkCanvas::Config8888 gSrcConfigs[] = {
-                SkCanvas::kNative_Premul_Config8888,
-                SkCanvas::kNative_Unpremul_Config8888,
-                SkCanvas::kBGRA_Premul_Config8888,
-                SkCanvas::kBGRA_Unpremul_Config8888,
-                SkCanvas::kRGBA_Premul_Config8888,
-                SkCanvas::kRGBA_Unpremul_Config8888,
+            static const struct {
+                SkColorType fColorType;
+                SkAlphaType fAlphaType;
+            } gSrcConfigs[] = {
+                { kRGBA_8888_SkColorType, kPremul_SkAlphaType },
+                { kRGBA_8888_SkColorType, kUnpremul_SkAlphaType },
+                { kBGRA_8888_SkColorType, kPremul_SkAlphaType },
+                { kBGRA_8888_SkColorType, kUnpremul_SkAlphaType },
             };
             for (size_t r = 0; r < SK_ARRAY_COUNT(testRects); ++r) {
                 const SkIRect& rect = testRects[r];
                 for (int tightBmp = 0; tightBmp < 2; ++tightBmp) {
                     for (size_t c = 0; c < SK_ARRAY_COUNT(gSrcConfigs); ++c) {
+                        const SkColorType ct = gSrcConfigs[c].fColorType;
+                        const SkAlphaType at = gSrcConfigs[c].fAlphaType;
+
                         fillCanvas(&canvas);
-                        SkCanvas::Config8888 config8888 = gSrcConfigs[c];
                         SkBitmap bmp;
-                        REPORTER_ASSERT(reporter, setupBitmap(&bmp, config8888, rect.width(), rect.height(), SkToBool(tightBmp)));
+                        REPORTER_ASSERT(reporter, setupBitmap(&bmp, ct, at, rect.width(),
+                                                              rect.height(), SkToBool(tightBmp)));
                         uint32_t idBefore = canvas.getDevice()->accessBitmap(false).getGenerationID();
 
-                        SkColorType ct;
-                        SkAlphaType at;
-                        sk_tool_utils::config8888_to_imagetypes(config8888, &ct, &at);
-                        sk_tool_utils::write_pixels(&canvas, bmp, rect.fLeft, rect.fTop, ct, at);
+                       // sk_tool_utils::write_pixels(&canvas, bmp, rect.fLeft, rect.fTop, ct, at);
+                        canvas.writePixels(bmp, rect.fLeft, rect.fTop);
 
                         uint32_t idAfter = canvas.getDevice()->accessBitmap(false).getGenerationID();
-                        REPORTER_ASSERT(reporter, checkWrite(reporter, &canvas, bmp, rect.fLeft, rect.fTop, config8888));
+                        REPORTER_ASSERT(reporter, checkWrite(reporter, &canvas, bmp, rect.fLeft, rect.fTop));
 
                         // we should change the genID iff pixels were actually written.
                         SkIRect canvasRect = SkIRect::MakeSize(canvas.getDeviceSize());
                         SkIRect writeRect = SkIRect::MakeXYWH(rect.fLeft, rect.fTop,
                                                               bmp.width(), bmp.height());
                         bool intersects = SkIRect::Intersects(canvasRect, writeRect) ;
                         REPORTER_ASSERT(reporter, intersects == (idBefore != idAfter));
                     }
                 }
             }
         }
     }
 }