Creating functions for uploading a mipmapped texture.

src/gpu/GrGpu.cpp

Index: src/gpu/GrGpu.cpp
diff --git a/src/gpu/GrGpu.cpp b/src/gpu/GrGpu.cpp
index 728fb880622010fa9495932d467b7f6df7d3ff04..a595eaebfb241dd440d89be1403c9311c827b98a 100644
--- a/src/gpu/GrGpu.cpp
+++ b/src/gpu/GrGpu.cpp
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2010 Google Inc.
  *
@@ -64,73 +63,110 @@ static GrSurfaceOrigin resolve_origin(GrSurfaceOrigin origin, bool renderTarget)
     }
 }
 
-GrTexture* GrGpu::createTexture(const GrSurfaceDesc& origDesc, bool budgeted,
-                                const void* srcData, size_t rowBytes) {
-    GrSurfaceDesc desc = origDesc;
-
-    if (!this->caps()->isConfigTexturable(desc.fConfig)) {
-        return NULL;
+/**
+ * Prior to creating a texture, make sure the type of texture being created is
+ * supported by calling check_texture_creation_params.
+ *
+ * @param caps The capabilities of the GL device.
+ * @param desc The descriptor of the texture to create.
+ * @param isRT Indicates if the texture be a render target.
+ */
+static bool check_texture_creation_params(const GrCaps& caps, const GrSurfaceDesc& desc,
+                                          bool* isRT) {
+    if (!caps.isConfigTexturable(desc.fConfig)) {
+        return false;
     }
 
-    bool isRT = SkToBool(desc.fFlags & kRenderTarget_GrSurfaceFlag);
-    if (isRT && !this->caps()->isConfigRenderable(desc.fConfig, desc.fSampleCnt > 0)) {
-        return NULL;
+    *isRT = SkToBool(desc.fFlags & kRenderTarget_GrSurfaceFlag);
+    if (*isRT && !caps.isConfigRenderable(desc.fConfig, desc.fSampleCnt > 0)) {
+        return false;
     }
 
-    // We currently not support multisampled textures
-    if (!isRT && desc.fSampleCnt > 0) {
-        return NULL;
+    // We currently do not support multisampled textures
+    if (!*isRT && desc.fSampleCnt > 0) {
+        return false;
     }
 
-    GrTexture *tex = NULL;
-
-    if (isRT) {
-        int maxRTSize = this->caps()->maxRenderTargetSize();
+    if (*isRT) {
+        int maxRTSize = caps.maxRenderTargetSize();
         if (desc.fWidth > maxRTSize || desc.fHeight > maxRTSize) {
-            return NULL;
+            return false;
         }
     } else {
-        int maxSize = this->caps()->maxTextureSize();
+        int maxSize = caps.maxTextureSize();
         if (desc.fWidth > maxSize || desc.fHeight > maxSize) {
-            return NULL;
+            return false;
         }
     }
+    return true;
+}
+
+GrTexture* GrGpu::createTexture(const GrSurfaceDesc& origDesc, bool budgeted,
+                                SkTArray<SkMipMapLevel>& texels) {
+    GrSurfaceDesc desc = origDesc;
+
+    const GrCaps* caps = this->caps();
+    if (!caps) {
+        return NULL;
+    } else {
+        bool isRT = false;
+        bool textureCreationParamsValid = check_texture_creation_params(*caps, desc, &isRT);
+        if (!textureCreationParamsValid) {
+            return NULL;
+        }
 
-    GrGpuResource::LifeCycle lifeCycle = budgeted ? GrGpuResource::kCached_LifeCycle :
-                                                    GrGpuResource::kUncached_LifeCycle;
+        desc.fSampleCnt = SkTMin(desc.fSampleCnt, caps->maxSampleCount());
+        // Attempt to catch un- or wrongly initialized sample counts;
+        SkASSERT(desc.fSampleCnt >= 0 && desc.fSampleCnt <= 64);
 
-    desc.fSampleCnt = SkTMin(desc.fSampleCnt, this->caps()->maxSampleCount());
-    // Attempt to catch un- or wrongly initialized sample counts;
-    SkASSERT(desc.fSampleCnt >= 0 && desc.fSampleCnt <= 64);
+        desc.fOrigin = resolve_origin(desc.fOrigin, isRT);
 
-    desc.fOrigin = resolve_origin(desc.fOrigin, isRT);
+        GrTexture *tex = NULL;
+        GrGpuResource::LifeCycle lifeCycle = budgeted ? GrGpuResource::kCached_LifeCycle :
+                                                        GrGpuResource::kUncached_LifeCycle;
 
-    if (GrPixelConfigIsCompressed(desc.fConfig)) {
-        // We shouldn't be rendering into this
-        SkASSERT(!isRT);
-        SkASSERT(0 == desc.fSampleCnt);
+        if (GrPixelConfigIsCompressed(desc.fConfig)) {
+            // We shouldn't be rendering into this
+            SkASSERT(!isRT);
+            SkASSERT(0 == desc.fSampleCnt);
 
-        if (!this->caps()->npotTextureTileSupport() &&
-            (!SkIsPow2(desc.fWidth) || !SkIsPow2(desc.fHeight))) {
-            return NULL;
-        }
+            if (!caps->npotTextureTileSupport() &&
+                (!SkIsPow2(desc.fWidth) || !SkIsPow2(desc.fHeight))) {
+                return NULL;
+            }
 
-        this->handleDirtyContext();
-        tex = this->onCreateCompressedTexture(desc, lifeCycle, srcData);
-    } else {
-        this->handleDirtyContext();
-        tex = this->onCreateTexture(desc, lifeCycle, srcData, rowBytes);
-    }
-    if (!this->caps()->reuseScratchTextures() && !isRT) {
-        tex->resourcePriv().removeScratchKey();
-    }
-    if (tex) {
-        fStats.incTextureCreates();
-        if (srcData) {
-            fStats.incTextureUploads();
+            this->handleDirtyContext();
+            tex = this->onCreateCompressedTexture(desc, lifeCycle, texels);
+        } else {
+            this->handleDirtyContext();
+            tex = this->onCreateTexture(desc, lifeCycle, texels);
+        }
+        if (tex) {
+            /* TODO: I am unsure how to use a scratch texture well with mipmaps

[bsalomon, 2015/08/26 18:30:11]

I think we should just include mip status in the scratch key and change the key
if mips get added lazily to a non-mipped texture.

[cblume, 2015/08/26 18:58:00]

Thinking out loud: A bool of "is mipmapped" may not be enough. If someone wanted
a scratch texture with 5 mipmap levels but they are provided a scratch texture
with only 4 then there will be a problem. So maybe mipmap level count is the
thing we need to add to the scratch texture. Maybe this also means we cannot
preallocate the scratch texture mipmap memory, which would be a significant
slowdown any time we need to add more levels.

[bsalomon, 2015/08/27 13:22:49]

Why don't we just require either just a base level or a full pyramid? The upper
levels are so small compared to the original that I don't know that it is worth
any complexity to save a tiny amount of space.

+            if (!caps->reuseScratchTextures() && !isRT) {
+                tex->resourcePriv().removeScratchKey();
+            }
+            */
+            fStats.incTextureCreates();
+            if (!texels.empty()) {
+                if (texels[0].fTexels) {
+                    fStats.incTextureUploads();
+                }
+            }
         }
+        return tex;
     }
-    return tex;
+}
+
+GrTexture* GrGpu::createTexture(const GrSurfaceDesc& desc, bool budgeted,
+                                const void* srcData, size_t rowBytes) {
+    SkMipMapLevel level(srcData, rowBytes);
+
+    const int mipLevelCount = 1;
+    SkTArray<SkMipMapLevel> levels(mipLevelCount);
+    levels.push_back(level);
+
+    return createTexture(desc, budgeted, levels);
 }
 
 bool GrGpu::attachStencilAttachmentToRenderTarget(GrRenderTarget* rt) {
@@ -243,17 +279,28 @@ bool GrGpu::readPixels(GrRenderTarget* target,
 
 bool GrGpu::writeTexturePixels(GrTexture* texture,
                                int left, int top, int width, int height,
-                               GrPixelConfig config, const void* buffer,
-                               size_t rowBytes) {
+                               GrPixelConfig config,
+                               SkTArray<SkMipMapLevel>& texels) {
     this->handleDirtyContext();
     if (this->onWriteTexturePixels(texture, left, top, width, height,
-                                   config, buffer, rowBytes)) {
+                                   config, texels)) {
         fStats.incTextureUploads();
         return true;
     }
     return false;
 }
 
+bool GrGpu::writeTexturePixels(GrTexture* texture,
+                               int left, int top, int width, int height,
+                               GrPixelConfig config, const void* buffer,
+                               size_t rowBytes) {
+    SkMipMapLevel mipLevel(buffer, rowBytes);
+    SkTArray<SkMipMapLevel> texels;
+    texels.push_back(mipLevel);
+
+    writeTexturePixels(texture, left, top, width, height, config, texels);
+}
+
 void GrGpu::resolveRenderTarget(GrRenderTarget* target) {
     SkASSERT(target);
     this->handleDirtyContext();