Add ES 3.0 fallback for instanced rendering

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"
 
@@ skipping 20 matching lines @@
     fUnpackFlipYSupport = false;
     fPackRowLengthSupport = false;
     fPackFlipYSupport = false;
     fTextureUsageSupport = false;
     fTextureRedSupport = false;
     fImagingSupport = false;
     fVertexArrayObjectSupport = false;
     fDirectStateAccessSupport = false;
     fDebugSupport = false;
     fES2CompatibilitySupport = false;
+    fDrawInstancedSupport = false;
     fDrawIndirectSupport = false;
     fMultiDrawIndirectSupport = false;
     fBaseInstanceSupport = false;
     fIsCoreProfile = false;
     fBindFragDataLocationSupport = false;
     fRectangleTextureSupport = false;
     fTextureSwizzleSupport = false;
     fRGBA8888PixelsOpsAreSlow = false;
     fPartialFBOReadIsSlow = false;
     fMipMapLevelAndLodControlSupport = false;
@@ skipping 444 matching lines @@
             SkASSERT(ctxInfo.hasExtension("GL_EXT_framebuffer_object"));
         }
     } else {
         // ES 3.0 supports mixed size FBO attachments, 2.0 does not.
         fOversizedStencilSupport = ctxInfo.version() >= GR_GL_VER(3, 0);
     }
 
     if (kGL_GrGLStandard == standard) {
         // 3.1 has draw_instanced but not instanced_arrays, for the time being we only care about
         // instanced arrays, but we could make this more granular if we wanted
-        fSupportsInstancedDraws =
+        fDrawInstancedSupport =
                 version >= GR_GL_VER(3, 2) ||
                 (ctxInfo.hasExtension("GL_ARB_draw_instanced") &&
                  ctxInfo.hasExtension("GL_ARB_instanced_arrays"));
     } else {
-        fSupportsInstancedDraws =
+        fDrawInstancedSupport =
                 version >= GR_GL_VER(3, 0) ||
                 (ctxInfo.hasExtension("GL_EXT_draw_instanced") &&
                  ctxInfo.hasExtension("GL_EXT_instanced_arrays"));
     }
 
     if (kGL_GrGLStandard == standard) {
         fDrawIndirectSupport = version >= GR_GL_VER(4,0) ||
                                ctxInfo.hasExtension("GL_ARB_draw_indirect");
         fBaseInstanceSupport = version >= GR_GL_VER(4,2);
         fMultiDrawIndirectSupport = version >= GR_GL_VER(4,3) ||
-                                    (!fBaseInstanceSupport && // The ARB extension has no base inst.
+                                    (fDrawIndirectSupport &&
+                                     !fBaseInstanceSupport && // The ARB extension has no base inst.
                                      ctxInfo.hasExtension("GL_ARB_multi_draw_indirect"));
     } else {
         fDrawIndirectSupport = version >= GR_GL_VER(3,1);
-        fMultiDrawIndirectSupport = ctxInfo.hasExtension("GL_EXT_multi_draw_indirect");
-        fBaseInstanceSupport = ctxInfo.hasExtension("GL_EXT_base_instance");
+        fMultiDrawIndirectSupport = fDrawIndirectSupport &&
+                                    ctxInfo.hasExtension("GL_EXT_multi_draw_indirect");
+        fBaseInstanceSupport = fDrawIndirectSupport &&
+                               ctxInfo.hasExtension("GL_EXT_base_instance");
     }
 
     this->initShaderPrecisionTable(ctxInfo, gli, glslCaps);
 
     if (contextOptions.fUseShaderSwizzling) {
         fTextureSwizzleSupport = false;
     }
 
     if (kGL_GrGLStandard == standard) {
         if ((version >= GR_GL_VER(4, 0) || ctxInfo.hasExtension("GL_ARB_sample_shading")) && 
@@ skipping 561 matching lines @@
     r.appendf("Unpack Flip Y support: %s\n", (fUnpackFlipYSupport ? "YES": "NO"));
     r.appendf("Pack Row length support: %s\n", (fPackRowLengthSupport ? "YES": "NO"));
     r.appendf("Pack Flip Y support: %s\n", (fPackFlipYSupport ? "YES": "NO"));
 
     r.appendf("Texture Usage support: %s\n", (fTextureUsageSupport ? "YES": "NO"));
     r.appendf("GL_R support: %s\n", (fTextureRedSupport ? "YES": "NO"));
     r.appendf("GL_ARB_imaging support: %s\n", (fImagingSupport ? "YES": "NO"));
     r.appendf("Vertex array object support: %s\n", (fVertexArrayObjectSupport ? "YES": "NO"));
     r.appendf("Direct state access support: %s\n", (fDirectStateAccessSupport ? "YES": "NO"));
     r.appendf("Debug support: %s\n", (fDebugSupport ? "YES": "NO"));
+    r.appendf("Draw instanced support: %s\n", (fDrawInstancedSupport ? "YES" : "NO"));
     r.appendf("Draw indirect support: %s\n", (fDrawIndirectSupport ? "YES" : "NO"));
     r.appendf("Multi draw indirect support: %s\n", (fMultiDrawIndirectSupport ? "YES" : "NO"));
     r.appendf("Base instance support: %s\n", (fBaseInstanceSupport ? "YES" : "NO"));
     r.appendf("RGBA 8888 pixel ops are slow: %s\n", (fRGBA8888PixelsOpsAreSlow ? "YES" : "NO"));
     r.appendf("Partial FBO read is slow: %s\n", (fPartialFBOReadIsSlow ? "YES" : "NO"));
     r.appendf("Bind uniform location support: %s\n", (fBindUniformLocationSupport ? "YES" : "NO"));
     r.appendf("Rectangle texture support: %s\n", (fRectangleTextureSupport? "YES" : "NO"));
     r.appendf("Texture swizzle support: %s\n", (fTextureSwizzleSupport ? "YES" : "NO"));
     r.appendf("BGRA to RGBA readback conversions are slow: %s\n",
               (fRGBAToBGRAReadbackConversionsAreSlow ? "YES" : "NO"));
@@ skipping 811 matching lines @@
 void GrGLCaps::onApplyOptionsOverrides(const GrContextOptions& options) {
     if (options.fEnableInstancedRendering) {
         fInstancedSupport = gr_instanced::GLInstancedRendering::CheckSupport(*this);
 #ifndef SK_BUILD_FOR_MAC
         // OS X doesn't seem to write correctly to floating point textures when using
         // glDraw*Indirect, regardless of the underlying GPU.
         fAvoidInstancedDrawsToFPTargets = true;
 #endif
     }
 }