Add compressed texture capabilities for GPU devices

src/gpu/gl/GrGLCaps.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLCaps.h"
 #include "GrGLContext.h"
@@ skipping 351 matching lines @@
     }
 
     if (GrGLCaps::kES_IMG_MsToTexture_MSFBOType == fMSFBOType) {
         GR_GL_GetIntegerv(gli, GR_GL_MAX_SAMPLES_IMG, &fMaxSampleCount);
     } else if (GrGLCaps::kNone_MSFBOType != fMSFBOType) {
         GR_GL_GetIntegerv(gli, GR_GL_MAX_SAMPLES, &fMaxSampleCount);
     }
 
     this->initConfigRenderableTable(ctxInfo);
 
+    this->initCompressedTextureSupport(ctxInfo);
+
     return true;
 }
 
 void GrGLCaps::initConfigRenderableTable(const GrGLContextInfo& ctxInfo) {
 
     // OpenGL < 3.0
     //  no support for render targets unless the GL_ARB_framebuffer_object
     //  extension is supported (in which case we get ALPHA, RED, RG, RGB,
     //  RGBA (ALPHA8, RGBA4, RGBA8) for OpenGL > 1.1). Note that we
     //  probably don't get R8 in this case.
@@ skipping 69 matching lines @@
 
     // If we don't support MSAA then undo any places above where we set a config as renderable with
     // msaa.
     if (kNone_MSFBOType == fMSFBOType) {
         for (int i = 0; i < kGrPixelConfigCnt; ++i) {
             fConfigRenderSupport[i][kYes_MSAA] = false;
         }
     }
 }
 
+void GrGLCaps::initCompressedTextureSupport(const GrGLContextInfo &ctxInfo) {
+    GrGLStandard standard = ctxInfo.standard();
+    GrGLVersion version = ctxInfo.version();
+
+    // glCompressedTexImage2D is available on all OpenGL ES devices...
+    // however, it is only available on the core profile after version 1.3

[bsalomon, 2014/05/23 13:40:04]

I think "core profile" is slightly confusing since OpenGL has a notion of a core
vs compatibility profile begining in version 3 where the core profile deprecates
a lot of functionality.  Maybe just "OpenGL" or "non-ES OpenGL". We and others
also sometimes refer to regular OpenGL as "desktop GL", though that can be
confusing as well.

[krajcevski, 2014/05/23 15:11:46]

Done.

+    if (kGL_GrGLStandard == standard && version < GR_GL_VER(1, 3)) {
+        return;
+    }
+
+    // Check for ETC1
+    bool hasETC1 = false;
+
+    // First check version for support
+    if (kGL_GrGLStandard == standard) {
+        hasETC1 =
+            version >= GR_GL_VER(4, 3) ||
+            ctxInfo.hasExtension("GL_ARB_ES3_compatibility");
+    } else {
+        hasETC1 =
+            version >= GR_GL_VER(3, 0) ||
+            ctxInfo.hasExtension("GL_OES_compressed_ETC1_RGB8_texture") ||
+            // ETC2 is a superset of ETC1, so we can just check for that, too.
+            (ctxInfo.hasExtension("GL_OES_compressed_ETC2_RGB8_texture") &&
+             ctxInfo.hasExtension("GL_OES_compressed_ETC2_RGBA8_texture"));
+    }
+    fCompressedFormatSupport[kETC1_GrCompressedFormat] = hasETC1;
+}
+
 bool GrGLCaps::readPixelsSupported(const GrGLInterface* intf,
                                    GrGLenum format,
                                    GrGLenum type) const {
     if (GR_GL_RGBA == format && GR_GL_UNSIGNED_BYTE == type) {
         // ES 2 guarantees this format is supported
         return true;
     }
 
     if (!fTwoFormatLimit) {
         // not limited by ES 2's constraints
@@ skipping 238 matching lines @@
     r.appendf("Two Format Limit: %s\n", (fTwoFormatLimit ? "YES": "NO"));
     r.appendf("Fragment coord conventions support: %s\n",
              (fFragCoordsConventionSupport ? "YES": "NO"));
     r.appendf("Vertex array object support: %s\n", (fVertexArrayObjectSupport ? "YES": "NO"));
     r.appendf("Use non-VBO for dynamic data: %s\n",
              (fUseNonVBOVertexAndIndexDynamicData ? "YES" : "NO"));
     r.appendf("Full screen clear is free: %s\n", (fFullClearIsFree ? "YES" : "NO"));
     r.appendf("Drops tile on zero divide: %s\n", (fDropsTileOnZeroDivide ? "YES" : "NO"));
     return r;
 }