Creating functions for uploading a mipmapped texture.

src/gpu/GrContext.cpp

Index: src/gpu/GrContext.cpp
diff --git a/src/gpu/GrContext.cpp b/src/gpu/GrContext.cpp
index c7e6ca949a7d22db30661449b7e05916f8c873c9..e6c29e03f26d038a370b09dd60bd25105d2faa83 100644
--- a/src/gpu/GrContext.cpp
+++ b/src/gpu/GrContext.cpp
@@ -105,7 +105,7 @@ void GrContext::DrawingMgr::flush() {
     }
 }
 
-GrDrawContext* GrContext::DrawingMgr::drawContext(const SkSurfaceProps* surfaceProps) { 
+GrDrawContext* GrContext::DrawingMgr::drawContext(const SkSurfaceProps* surfaceProps) {
     if (this->abandoned()) {
         return nullptr;
     }
@@ -320,20 +320,31 @@ bool sw_convert_to_premul(GrPixelConfig srcConfig, int width, int height, size_t
 
 bool GrContext::writeSurfacePixels(GrSurface* surface,
                                    int left, int top, int width, int height,
-                                   GrPixelConfig srcConfig, const void* buffer, size_t rowBytes,
+                                   GrPixelConfig srcConfig, const SkTArray<SkMipMapLevel>& texels,
                                    uint32_t pixelOpsFlags) {
     RETURN_FALSE_IF_ABANDONED
     ASSERT_OWNED_RESOURCE(surface);
     SkASSERT(surface);
 
+    SkTArray<SkMipMapLevel> texelsCopy(texels);

[bsalomon, 2015/09/15 13:14:11]

Why do we need to copy the mip array?

[cblume, 2015/09/16 18:40:46]

Further down there is a call to GrSurfacePriv::AdjustWritePixelParams inside a
loop over each mipmap level. That call changes the mipmap level texel pointer to
adjust for texture offset (maybe we are writing somewhere to the center of the
texture, not to the top left).

The array being copied is filled with lightweight objects (a pointer to the
texel data for that level and the row bytes for that level). The actual texel
data is not being copied.

+
     this->testPMConversionsIfNecessary(pixelOpsFlags);
 
     // Trim the params here so that if we wind up making a temporary surface it can be as small as
     // necessary and because GrGpu::getWritePixelsInfo requires it.
-    if (!GrSurfacePriv::AdjustWritePixelParams(surface->width(), surface->height(),
-                                               GrBytesPerPixel(srcConfig), &left, &top, &width,
-                                               &height, &buffer, &rowBytes)) {
-        return false;
+    auto currentMipHeight = height;
+    auto currentMipWidth = width;
+    for (auto currentMipLevel = texelsCopy.count() - 1; currentMipLevel >= 0; currentMipLevel--) {
+        auto& currentMipMap = texelsCopy[currentMipLevel];
+        if (!GrSurfacePriv::AdjustWritePixelParams(surface->width(), surface->height(),
+                                                   GrBytesPerPixel(srcConfig), &left, &top,
+                                                   &currentMipWidth, &currentMipHeight,
+                                                   &currentMipMap.fTexels,
+                                                   &currentMipMap.fRowBytes)) {
+            return false;
+        }
+        currentMipHeight /= 2;
+        currentMipWidth /= 2;
     }
 
     bool applyPremulToSrc = false;
@@ -352,7 +363,7 @@ bool GrContext::writeSurfacePixels(GrSurface* surface,
     }
 
     GrGpu::WritePixelTempDrawInfo tempDrawInfo;
-    if (!fGpu->getWritePixelsInfo(surface, width, height, rowBytes, srcConfig, &drawPreference,
+    if (!fGpu->getWritePixelsInfo(surface, width, height, srcConfig, &drawPreference,
                                   &tempDrawInfo)) {
         return false;
     }
@@ -404,19 +415,27 @@ bool GrContext::writeSurfacePixels(GrSurface* surface,
                 this->flush();
             }
             if (applyPremulToSrc) {
-                size_t tmpRowBytes = 4 * width;
-                tmpPixels.reset(width * height);
-                if (!sw_convert_to_premul(srcConfig, width, height, rowBytes, buffer, tmpRowBytes,
-                                          tmpPixels.get())) {
-                    return false;
+                auto currentWidth = width;
+                auto currentHeight = height;
+                for (auto currentMipLevel = texelsCopy.count() - 1; currentMipLevel >= 0; currentMipLevel--) {
+                    size_t tmpRowBytes = 4 * currentWidth;
+                    tmpPixels.reset(currentWidth * currentHeight);
+                    auto& currentMipMap = texelsCopy[currentMipLevel];
+                    if (!sw_convert_to_premul(srcConfig, currentWidth, currentHeight,
+                                              currentMipMap.fRowBytes,
+                                              currentMipMap.fTexels, tmpRowBytes,
+                                              tmpPixels.get())) {
+                        return false;
+                    }
+                    currentMipMap.fRowBytes = tmpRowBytes;
+                    currentMipMap.fTexels = tmpPixels.get();
+                    currentWidth /= 2;
+                    currentHeight /= 2;
                 }
-                rowBytes = tmpRowBytes;
-                buffer = tmpPixels.get();
                 applyPremulToSrc = false;
             }
             if (!fGpu->writePixels(tempTexture, 0, 0, width, height,
-                                   tempDrawInfo.fTempSurfaceDesc.fConfig, buffer,
-                                   rowBytes)) {
+                                   tempDrawInfo.fTempSurfaceDesc.fConfig, texelsCopy)) {
                 return false;
             }
             SkMatrix matrix;
@@ -436,21 +455,42 @@ bool GrContext::writeSurfacePixels(GrSurface* surface,
     }
     if (!tempTexture) {
         if (applyPremulToSrc) {
-            size_t tmpRowBytes = 4 * width;
-            tmpPixels.reset(width * height);
-            if (!sw_convert_to_premul(srcConfig, width, height, rowBytes, buffer, tmpRowBytes,
-                                      tmpPixels.get())) {
-                return false;
+            auto currentWidth = width;
+            auto currentHeight = height;
+            for (auto currentMipLevel = texelsCopy.count() - 1; currentMipLevel >= 0; currentMipLevel--) {
+                size_t tmpRowBytes = 4 * currentWidth;
+                tmpPixels.reset(currentWidth * currentHeight);
+                auto& currentMipMap = texelsCopy[currentMipLevel];
+                if (!sw_convert_to_premul(srcConfig, currentWidth, currentHeight,
+                                          currentMipMap.fRowBytes, currentMipMap.fTexels,
+                                          tmpRowBytes, tmpPixels.get())) {
+                    return false;
+                }
+                currentMipMap.fRowBytes = tmpRowBytes;
+                currentMipMap.fTexels = tmpPixels.get();
+                currentWidth /= 2;
+                currentHeight /= 2;
             }
-            rowBytes = tmpRowBytes;
-            buffer = tmpPixels.get();
             applyPremulToSrc = false;
         }
-        return fGpu->writePixels(surface, left, top, width, height, srcConfig, buffer, rowBytes);
+        return fGpu->writePixels(surface, left, top, width, height, srcConfig, texelsCopy);
     }
     return true;
 }
 
+bool GrContext::writeSurfacePixels(GrSurface* surface,
+                                   int left, int top, int width, int height,
+                                   GrPixelConfig srcConfig, const void* buffer, size_t rowBytes,
+                                   uint32_t pixelOpsFlags) {
+    SkMipMapLevel level(buffer, rowBytes);
+    const int mipLevelCount = 1;
+    SkTArray<SkMipMapLevel> texels(mipLevelCount);
+    texels.push_back(level);
+
+    return this->writeSurfacePixels(surface, left, top, width, height, srcConfig, texels,
+                                    pixelOpsFlags);
+}
+
 bool GrContext::readSurfacePixels(GrSurface* src,
                                   int left, int top, int width, int height,
                                   GrPixelConfig dstConfig, void* buffer, size_t rowBytes,