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

src/gpu/GrContext.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 "GrContext.h"
 
 #include "effects/GrSingleTextureEffect.h"
 #include "effects/GrConfigConversionEffect.h"
 
 #include "GrAARectRenderer.h"
 #include "GrBufferAllocPool.h"
 #include "GrGpu.h"
 #include "GrDrawTargetCaps.h"
 #include "GrIndexBuffer.h"
 #include "GrInOrderDrawBuffer.h"
 #include "GrOvalRenderer.h"
 #include "GrPathRenderer.h"
 #include "GrPathUtils.h"
 #include "GrResourceCache.h"
 #include "GrSoftwarePathRenderer.h"
 #include "GrStencilBuffer.h"
 #include "GrTextStrike.h"
+#include "SkGr.h"
 #include "SkRTConf.h"
 #include "SkRRect.h"
 #include "SkStrokeRec.h"
 #include "SkTLazy.h"
 #include "SkTLS.h"
 #include "SkTraceEvent.h"
 
 // It can be useful to set this to false to test whether a bug is caused by using the
 // InOrderDrawBuffer, to compare performance of using/not using InOrderDrawBuffer, or to make
 // debugging simpler.
@@ skipping 1214 matching lines @@
                                                 config, buffer, rowBytes,
                                                 flags);
         }
 
         return false;
     }
 }
 
 #include "SkConfig8888.h"
 
-namespace {
-/**
- * Converts a GrPixelConfig to a SkCanvas::Config8888. Only byte-per-channel
- * formats are representable as Config8888 and so the function returns false
- * if the GrPixelConfig has no equivalent Config8888.
- */
-bool grconfig_to_config8888(GrPixelConfig config,
-                            bool unpremul,
-                            SkCanvas::Config8888* config8888) {
-    switch (config) {
-        case kRGBA_8888_GrPixelConfig:
-            if (unpremul) {
-                *config8888 = SkCanvas::kRGBA_Unpremul_Config8888;
-            } else {
-                *config8888 = SkCanvas::kRGBA_Premul_Config8888;
-            }
-            return true;
-        case kBGRA_8888_GrPixelConfig:
-            if (unpremul) {
-                *config8888 = SkCanvas::kBGRA_Unpremul_Config8888;
-            } else {
-                *config8888 = SkCanvas::kBGRA_Premul_Config8888;
-            }
-            return true;
-        default:
-            return false;
+// toggles between RGBA and BGRA
+static SkColorType toggle_colortype32(SkColorType ct) {
+    if (kRGBA_8888_SkColorType == ct) {
+        return kBGRA_8888_SkColorType;
+    } else {
+        SkASSERT(kBGRA_8888_SkColorType == ct);
+        return kRGBA_8888_SkColorType;
     }
 }
 
-// It returns a configuration with where the byte position of the R & B components are swapped in
-// relation to the input config. This should only be called with the result of
-// grconfig_to_config8888 as it will fail for other configs.
-SkCanvas::Config8888 swap_config8888_red_and_blue(SkCanvas::Config8888 config8888) {
-    switch (config8888) {
-        case SkCanvas::kBGRA_Premul_Config8888:
-            return SkCanvas::kRGBA_Premul_Config8888;
-        case SkCanvas::kBGRA_Unpremul_Config8888:
-            return SkCanvas::kRGBA_Unpremul_Config8888;
-        case SkCanvas::kRGBA_Premul_Config8888:
-            return SkCanvas::kBGRA_Premul_Config8888;
-        case SkCanvas::kRGBA_Unpremul_Config8888:
-            return SkCanvas::kBGRA_Unpremul_Config8888;
-        default:
-            GrCrash("Unexpected input");
-            return SkCanvas::kBGRA_Unpremul_Config8888;;
-    }
-}
-}
-
 bool GrContext::readRenderTargetPixels(GrRenderTarget* target,
                                        int left, int top, int width, int height,
                                        GrPixelConfig dstConfig, void* buffer, size_t rowBytes,
                                        uint32_t flags) {
     ASSERT_OWNED_RESOURCE(target);
 
     if (NULL == target) {
         target = fRenderTarget.get();
         if (NULL == target) {
             return false;
@@ skipping 104 matching lines @@
             }
         }
     }
     if (!fGpu->readPixels(target,
                           left, top, width, height,
                           readConfig, buffer, rowBytes)) {
         return false;
     }
     // Perform any conversions we weren't able to perform using a scratch texture.
     if (unpremul || swapRAndB) {
-        // These are initialized to suppress a warning
-        SkCanvas::Config8888 srcC8888 = SkCanvas::kNative_Premul_Config8888;
-        SkCanvas::Config8888 dstC8888 = SkCanvas::kNative_Premul_Config8888;
+        SkDstPixelInfo dstPI;
+        if (!GrPixelConfig2ColorType(dstConfig, &dstPI.fColorType)) {
+            return false;
+        }
+        dstPI.fAlphaType = kUnpremul_SkAlphaType;
+        dstPI.fPixels = buffer;
+        dstPI.fRowBytes = rowBytes;
 
-        SkDEBUGCODE(bool c8888IsValid =) grconfig_to_config8888(dstConfig, false, &srcC8888);
-        grconfig_to_config8888(dstConfig, unpremul, &dstC8888);
+        SkSrcPixelInfo srcPI;
+        srcPI.fColorType = swapRAndB ? toggle_colortype32(dstPI.fColorType) : dstPI.fColorType;
+        srcPI.fAlphaType = kPremul_SkAlphaType;
+        srcPI.fPixels = buffer;
+        srcPI.fRowBytes = rowBytes;
 
-        if (swapRAndB) {
-            SkASSERT(c8888IsValid); // we should only do r/b swap on 8888 configs
-            srcC8888 = swap_config8888_red_and_blue(srcC8888);
-        }
-        SkASSERT(c8888IsValid);
-        uint32_t* b32 = reinterpret_cast<uint32_t*>(buffer);
-        SkConvertConfig8888Pixels(b32, rowBytes, dstC8888,
-                                  b32, rowBytes, srcC8888,
-                                  width, height);
+        return srcPI.convertPixelsTo(&dstPI, width, height);
     }
     return true;
 }
 
 void GrContext::resolveRenderTarget(GrRenderTarget* target) {
     SkASSERT(target);
     ASSERT_OWNED_RESOURCE(target);
     // In the future we may track whether there are any pending draws to this
     // target. We don't today so we always perform a flush. We don't promise
     // this to our clients, though.
@@ skipping 99 matching lines @@
     // allocate a tmp buffer and sw convert the pixels to premul
     SkAutoSTMalloc<128 * 128, uint32_t> tmpPixels(0);
 
     if (kUnpremul_PixelOpsFlag & flags) {
         if (!GrPixelConfigIs8888(srcConfig)) {
             return false;
         }
         effect.reset(this->createUPMToPMEffect(texture, swapRAndB, textureMatrix));
         // handle the unpremul step on the CPU if we couldn't create an effect to do it.
         if (NULL == effect) {
-            SkCanvas::Config8888 srcConfig8888, dstConfig8888;
-            SkDEBUGCODE(bool success = )
-            grconfig_to_config8888(srcConfig, true, &srcConfig8888);
-            SkASSERT(success);
-            SkDEBUGCODE(success = )
-            grconfig_to_config8888(srcConfig, false, &dstConfig8888);
-            SkASSERT(success);
-            const uint32_t* src = reinterpret_cast<const uint32_t*>(buffer);
-            tmpPixels.reset(width * height);
-            SkConvertConfig8888Pixels(tmpPixels.get(), 4 * width, dstConfig8888,
-                                      src, rowBytes, srcConfig8888,
-                                      width, height);
+            SkSrcPixelInfo srcPI;
+            if (!GrPixelConfig2ColorType(srcConfig, &srcPI.fColorType)) {
+                return false;
+            }
+            srcPI.fAlphaType = kUnpremul_SkAlphaType;
+            srcPI.fPixels = buffer;
+            srcPI.fRowBytes = rowBytes;
+
+            SkDstPixelInfo dstPI;
+            dstPI.fColorType = srcPI.fColorType;
+            dstPI.fAlphaType = kPremul_SkAlphaType;
+            dstPI.fPixels = tmpPixels.get();
+            dstPI.fRowBytes = 4 * width;
+
+            if (!srcPI.convertPixelsTo(&dstPI, width, height)) {
+                return false;
+            }
+
             buffer = tmpPixels.get();
             rowBytes = 4 * width;
         }
     }
     if (NULL == effect) {
         effect.reset(GrConfigConversionEffect::Create(texture,
                                                       swapRAndB,
                                                       GrConfigConversionEffect::kNone_PMConversion,
                                                       textureMatrix));
     }
@@ skipping 207 matching lines @@
     }
     return path;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 #if GR_CACHE_STATS
 void GrContext::printCacheStats() const {
     fTextureCache->printStats();
 }
 #endif