Creating functions for uploading a mipmapped texture.

src/gpu/GrTextureProvider.cpp

Index: src/gpu/GrTextureProvider.cpp
diff --git a/src/gpu/GrTextureProvider.cpp b/src/gpu/GrTextureProvider.cpp
index cb652f7a7fd8c2e27b46fb7a4c802a4031b900e1..814659c88f7dfa7df85eb56fe48eb504e3fe16d7 100644
--- a/src/gpu/GrTextureProvider.cpp
+++ b/src/gpu/GrTextureProvider.cpp
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2015 Google Inc.
  *
@@ -18,7 +17,7 @@ enum ScratchTextureFlags {
 };
 
 GrTexture* GrTextureProvider::createTexture(const GrSurfaceDesc& desc, bool budgeted,
-                                            const void* srcData, size_t rowBytes) {
+                                            const SkTArray<SkMipMapLevel>& texels) {
     if (this->isAbandoned()) {
         return nullptr;
     }
@@ -27,20 +26,34 @@ GrTexture* GrTextureProvider::createTexture(const GrSurfaceDesc& desc, bool budg
         return nullptr;
     }
     if (!GrPixelConfigIsCompressed(desc.fConfig)) {
-        static const uint32_t kFlags = kExact_ScratchTextureFlag |
-                                       kNoCreate_ScratchTextureFlag;
-        if (GrTexture* texture = this->refScratchTexture(desc, kFlags)) {
-            if (!srcData || texture->writePixels(0, 0, desc.fWidth, desc.fHeight, desc.fConfig,
-                                                 srcData, rowBytes)) {
-                if (!budgeted) {
-                    texture->resourcePriv().makeUnbudgeted();
+        // In the case of mipmaps, do not use a scratch texture
+        if (texels.count() < 2) {
+            const SkMipMapLevel& baseMipLevel = texels[0];
+            static const uint32_t kFlags = kExact_ScratchTextureFlag |
+                                           kNoCreate_ScratchTextureFlag;
+            if (GrTexture* texture = this->refScratchTexture(desc, kFlags)) {
+                if (texture->writePixels(0, 0, desc.fWidth, desc.fHeight, desc.fConfig,

[bsalomon, 2016/01/08 16:43:29]

This works when writePixels uses an intermediate temporary texture that gets
rendered to texture?

[cblume, 2016/01/09 01:26:56]

I think I don't follow what you are asking.
This path is inside "if (texels.count() < 2) {".
This is the non-mipmap path.
So it should be exactly the same as before this patch.

It is missing the "!srcData ||" prior to writing the pixels. So if the texture
data is null, it would be different. However, inside writePixels we check if the
data is null as well:
https://codereview.chromium.org/1249543003/diff/1210001/src/gpu/GrGpu.cpp

So I believe this should work the way it always has.

Perhaps I should explicitly shortcut if there is no data just for clarity's sake
or because that decision is expected to be made at this level?

[bsalomon, 2016/01/11 17:16:38]

Got it, my misunderstanding.

+                                         baseMipLevel.fTexelsOrOffset, baseMipLevel.fRowBytes)) {
+                    if (!budgeted) {
+                        texture->resourcePriv().makeUnbudgeted();
+                    }
+                    return texture;
                 }
-                return texture;
+                texture->unref();
             }
-            texture->unref();
         }
     }
-    return fGpu->createTexture(desc, budgeted, srcData, rowBytes);
+    return fGpu->createTexture(desc, budgeted, texels);
+}
+
+GrTexture* GrTextureProvider::createTexture(const GrSurfaceDesc& desc, bool budgeted,
+                                            const void* srcData, size_t rowBytes) {
+    SkMipMapLevel level(srcData, rowBytes, desc.fWidth, desc.fHeight);
+    const int mipLevelCount = 1;
+    SkTArray<SkMipMapLevel> texels(mipLevelCount);
+    texels.push_back(level);
+
+    return this->createTexture(desc, budgeted, texels);
 }
 
 GrTexture* GrTextureProvider::createApproxTexture(const GrSurfaceDesc& desc) {