One more pass at getting half float texture configs correct.

Added in check for sized internal format.
Made choice between RED and ALPHA orthogonal to HALF_FLOAT and
HALF_FLOAT_OES.
Enabled rendertarget support on ES 2.0.

Review URL: https://codereview.chromium.org/805033002

2 files changed, 28 insertions, 14 deletions

diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index c1eb6e10e2..cfb9558c76 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -497,10 +497,17 @@ void GrGLCaps::initConfigRenderableTable(const GrGLContextInfo& ctxInfo) {
         if (kGL_GrGLStandard == standard) {
             fConfigRenderSupport[kAlpha_half_GrPixelConfig][kNo_MSAA] = true;
             fConfigRenderSupport[kAlpha_half_GrPixelConfig][kYes_MSAA] = true;
+        } else if (ctxInfo.version() >= GR_GL_VER(3,0)) {
+            fConfigRenderSupport[kAlpha_half_GrPixelConfig][kNo_MSAA] = true;
+            // for now we don't support floating point MSAA on ES
+            fConfigRenderSupport[kAlpha_half_GrPixelConfig][kYes_MSAA] = false;
         } else {
-            // in theory, check for "GL_EXT_color_buffer_half_float" 
-            // for now we don't support half float alpha render target on ES
-            fConfigRenderSupport[kAlpha_half_GrPixelConfig][kNo_MSAA] = false;
+            if (ctxInfo.hasExtension("GL_EXT_color_buffer_half_float") && fTextureRedSupport) {
+                fConfigRenderSupport[kAlpha_half_GrPixelConfig][kNo_MSAA] = true;
+            } else {
+                fConfigRenderSupport[kAlpha_half_GrPixelConfig][kNo_MSAA] = false;
+            }
+            // for now we don't support floating point MSAA on ES
             fConfigRenderSupport[kAlpha_half_GrPixelConfig][kYes_MSAA] = false;
         }
     }
@@ -649,10 +656,10 @@ void GrGLCaps::initConfigTexturableTable(const GrGLContextInfo& ctxInfo, const G
     bool hasHalfFPTextures = version >= GR_GL_VER(3, 1);
     if (!hasHalfFPTextures) {
         hasHalfFPTextures = ctxInfo.hasExtension("GL_ARB_texture_float") ||
-        (ctxInfo.hasExtension("GL_OES_texture_half_float_linear") &&
-         ctxInfo.hasExtension("GL_OES_texture_half_float"));
+                            (ctxInfo.hasExtension("GL_OES_texture_half_float_linear") &&
+                             ctxInfo.hasExtension("GL_OES_texture_half_float"));
     }
-    fConfigTextureSupport[kAlpha_half_GrPixelConfig] = hasHalfFPTextures && fTextureRedSupport;
+    fConfigTextureSupport[kAlpha_half_GrPixelConfig] = hasHalfFPTextures;
 }
 
 bool GrGLCaps::doReadPixelsSupported(const GrGLInterface* intf,
diff --git a/src/gpu/gl/GrGpuGL.cpp b/src/gpu/gl/GrGpuGL.cpp
index 92b00c3f5c..5987c7000f 100644
--- a/src/gpu/gl/GrGpuGL.cpp
+++ b/src/gpu/gl/GrGpuGL.cpp
@@ -2386,18 +2386,25 @@ bool GrGLGpu::configToGLFormats(GrPixelConfig config,
             break;
 
         case kAlpha_half_GrPixelConfig:
-            if (kGLES_GrGLStandard == this->glStandard() && this->glVersion() < GR_GL_VER(3, 1)) {
-                *internalFormat = GR_GL_ALPHA;
-                *externalFormat = GR_GL_ALPHA;
-                *externalType = GR_GL_HALF_FLOAT_OES;
-            } else if (this->glCaps().textureRedSupport()) {
-                *internalFormat = GR_GL_R16F;
+            if (this->glCaps().textureRedSupport()) {
+                if (getSizedInternalFormat) {
+                    *internalFormat = GR_GL_R16F;
+                } else {
+                    *internalFormat = GR_GL_RED;
+                }
                 *externalFormat = GR_GL_RED;
-                *externalType = GR_GL_HALF_FLOAT;
             } else {
-                *internalFormat = GR_GL_ALPHA16F;
+                if (getSizedInternalFormat) {
+                    *internalFormat = GR_GL_ALPHA16F;
+                } else {
+                    *internalFormat = GR_GL_ALPHA;
+                }
                 *externalFormat = GR_GL_ALPHA;
+            }
+            if (kGL_GrGLStandard == this->glStandard() || this->glVersion() >= GR_GL_VER(3, 0)) {
                 *externalType = GR_GL_HALF_FLOAT;
+            } else {
+                *externalType = GR_GL_HALF_FLOAT_OES;
             }
             break;