Use scratch with LATC data if possible

src/gpu/GrSWMaskHelper.cpp

Index: src/gpu/GrSWMaskHelper.cpp
diff --git a/src/gpu/GrSWMaskHelper.cpp b/src/gpu/GrSWMaskHelper.cpp
index 697500f329dda0b641a300c7e46213bc50a57288..0ae63d85277c9aa98f65936a5a81a460ab1b6a46 100644
--- a/src/gpu/GrSWMaskHelper.cpp
+++ b/src/gpu/GrSWMaskHelper.cpp
@@ -125,26 +125,37 @@ bool GrSWMaskHelper::getTexture(GrAutoScratchTexture* texture) {
     GrTextureDesc desc;
     desc.fWidth = fBM.width();
     desc.fHeight = fBM.height();
-    desc.fConfig = kAlpha_8_GrPixelConfig;
+
+    static const int kLATCBlockSize = 4;

[robertphillips, 2014/06/12 14:43:33]

1 line for this?
Don't we also need to guard this with a GR_COMPRESS_ALPHA_MASK ?

[krajcevski, 2014/06/12 15:13:32]

Done.

+    if (desc.fWidth % kLATCBlockSize == 0 &&
+        desc.fHeight % kLATCBlockSize == 0) {
+        desc.fConfig = kLATC_GrPixelConfig;
+    } else {
+        desc.fConfig = kAlpha_8_GrPixelConfig;
+    }
 
     texture->set(fContext, desc);
     return NULL != texture->texture();
 }
 

[robertphillips, 2014/06/12 14:43:33]

I don't know if it would be worth it but it looks like we could fuse
toLATCTexture and toTexture into one method.

[krajcevski, 2014/06/12 15:13:32]

Done.

-GrTexture* GrSWMaskHelper::toLATCTexture(GrContext* ctx) {
+void GrSWMaskHelper::toLATCTexture(GrTexture* texture) {
     // Encode the BM into LATC data:
     SkAutoLockPixels alp(fBM);
     SkTextureCompressor::Format format = SkTextureCompressor::kLATC_Format;
     SkAutoDataUnref latcData(SkTextureCompressor::CompressBitmapToFormat(fBM, format));
-    if (NULL == latcData) {
-        return NULL;
-    }
+    SkASSERT(NULL != latcData);
 
-    GrTextureDesc desc;
-    desc.fWidth = fBM.width();
-    desc.fHeight = fBM.height();
-    desc.fConfig = kLATC_GrPixelConfig;
-    return ctx->getGpu()->createTexture(desc, latcData->bytes(), 0);
+    // If we aren't reusing scratch textures we don't need to flush before
+    // writing since no one else will be using 'texture'
+    bool reuseScratch = fContext->getGpu()->caps()->reuseScratchTextures();
+
+    // Since we're uploading to it, and it's compressed, 'texture' shouldn't
+    // have a render target.
+    SkASSERT(NULL == texture->asRenderTarget());
+
+    texture->writePixels(0, 0, fBM.width(), fBM.height(),
+                         kLATC_GrPixelConfig, latcData->bytes(), 0,
+                         reuseScratch ? 0 : GrContext::kDontFlush_PixelOpsFlag);
 }
 
 /**
@@ -153,6 +164,16 @@ GrTexture* GrSWMaskHelper::toLATCTexture(GrContext* ctx) {
 void GrSWMaskHelper::toTexture(GrTexture *texture) {

[robertphillips, 2014/06/12 14:43:33]

toLATCTexture has its own alp - move this one down?

[krajcevski, 2014/06/12 15:13:32]

Done.

     SkAutoLockPixels alp(fBM);
 
+#if GR_COMPRESS_ALPHA_MASK
+    // First see if we should compress this texture before uploading.
+    if (texture->config() == kLATC_GrPixelConfig) {
+        this->toLATCTexture(texture);
+        return;
+    }
+#endif
+
+    // Looks like we have to send a full A8 texture. 
+
     // If we aren't reusing scratch textures we don't need to flush before
     // writing since no one else will be using 'texture'
     bool reuseScratch = fContext->getGpu()->caps()->reuseScratchTextures();
@@ -186,15 +207,6 @@ GrTexture* GrSWMaskHelper::DrawPathMaskToTexture(GrContext* context,
 
     helper.draw(path, stroke, SkRegion::kReplace_Op, antiAlias, 0xFF);
 
-#if GR_COMPRESS_ALPHA_MASK 
-    // Can we create an LATC texture?
-    GrTexture *latc = helper.toLATCTexture(context);
-    if (NULL != latc) {
-        return latc;
-    }
-#endif
-
-    // Looks like we have to send a full A8 texture. 
     GrAutoScratchTexture ast;
     if (!helper.getTexture(&ast)) {
         return NULL;