Make readpixels work on GrTextures

src/gpu/GrSurface.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrSurface.h"
 #include "GrSurfacePriv.h"
 
 #include "SkBitmap.h"
 #include "SkGr.h"
 #include "SkImageEncoder.h"
 #include <stdio.h>
 
+template<typename T> static bool adjust_params(int surfaceWidth,
+                                               int surfaceHeight,
+                                               size_t bpp,
+                                               int* left, int* top, int* width, int* height,
+                                               T** data,
+                                               size_t* rowBytes) {
+    if (!*rowBytes) {
+        *rowBytes = *width * bpp;
+    }
+
+    SkIRect subRect = SkIRect::MakeXYWH(*left, *top, *width, *height);
+    SkIRect bounds = SkIRect::MakeWH(surfaceWidth, surfaceHeight);
+
+    if (!subRect.intersect(bounds)) {
+        return false;
+    }
+    *data = reinterpret_cast<void*>(reinterpret_cast<intptr_t>(*data) +
+            (subRect.fTop - *top) * *rowBytes + (subRect.fLeft - *left) * bpp);
+
+    *left = subRect.fLeft;
+    *top = subRect.fTop;
+    *width = subRect.width();
+    *height = subRect.height();
+    return true;
+}
+
+bool GrSurfacePriv::AdjustReadPixelParams(int surfaceWidth,
+                                          int surfaceHeight,
+                                          size_t bpp,
+                                          int* left, int* top, int* width, int* height,
+                                          void** data,
+                                          size_t* rowBytes) {
+    return adjust_params<void>(surfaceWidth, surfaceHeight, bpp, left, top, width, height, data,
+                               rowBytes);
+}
+
+bool GrSurfacePriv::AdjustWritePixelParams(int surfaceWidth,
+                                           int surfaceHeight,
+                                           size_t bpp,
+                                           int* left, int* top, int* width, int* height,
+                                           const void** data,
+                                           size_t* rowBytes) {
+    return adjust_params<const void>(surfaceWidth, surfaceHeight, bpp, left, top, width, height,
+                                     data, rowBytes);
+}
+
+
+//////////////////////////////////////////////////////////////////////////////
+
 bool GrSurface::writePixels(int left, int top, int width, int height,
                             GrPixelConfig config, const void* buffer, size_t rowBytes,
                             uint32_t pixelOpsFlags) {
     // go through context so that all necessary flushing occurs
     GrContext* context = this->getContext();
     if (NULL == context) {
         return false;
     }
     return context->writeSurfacePixels(this, left, top, width, height, config, buffer, rowBytes,
                                        pixelOpsFlags);
 }
 
 bool GrSurface::readPixels(int left, int top, int width, int height,
                            GrPixelConfig config, void* buffer, size_t rowBytes,
                            uint32_t pixelOpsFlags) {
     // go through context so that all necessary flushing occurs
     GrContext* context = this->getContext();
     if (NULL == context) {
         return false;
     }
-    GrRenderTarget* target = this->asRenderTarget();
-    if (target) {
-        return context->readRenderTargetPixels(target, left, top, width, height, config, buffer,
-                                               rowBytes, pixelOpsFlags);
-    }
-    return false;
+    return context->readSurfacePixels(this, left, top, width, height, config, buffer,
+                                      rowBytes, pixelOpsFlags);
 }
 
 SkImageInfo GrSurface::info(SkAlphaType alphaType) const {
     SkColorType colorType;
     SkColorProfileType profileType;
     if (!GrPixelConfig2ColorAndProfileType(this->config(), &colorType, &profileType)) {
         sk_throw();
     }
     return SkImageInfo::Make(this->width(), this->height(), colorType, alphaType,
                              profileType);
@@ skipping 76 matching lines @@
 
 void GrSurface::onRelease() {
     this->invokeReleaseProc();
     this->INHERITED::onRelease();
 }
 
 void GrSurface::onAbandon() {
     this->invokeReleaseProc();
     this->INHERITED::onAbandon();
 }