Initial version of external_oes texture support and unit test

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 28 matching lines @@
     fTwoFormatLimit = false;
     fVertexArrayObjectSupport = false;
     fInstancedDrawingSupport = false;
     fDirectStateAccessSupport = false;
     fDebugSupport = false;
     fES2CompatibilitySupport = false;
     fMultisampleDisableSupport = false;
     fUseNonVBOVertexAndIndexDynamicData = false;
     fIsCoreProfile = false;
     fBindFragDataLocationSupport = false;
+    fExternalTextureSupport = false;
     fSRGBWriteControl = false;
     fRGBA8888PixelsOpsAreSlow = false;
     fPartialFBOReadIsSlow = false;
 
     fReadPixelsSupportedCache.reset();
 
     fShaderCaps.reset(new GrGLSLCaps(contextOptions));
 
     this->init(contextOptions, ctxInfo, glInterface);
 }
@@ skipping 193 matching lines @@
             fBindFragDataLocationSupport = true;
         }
     }
 
 #if 0 // Disabled due to https://bug.skia.org/4454
     fBindUniformLocationSupport = ctxInfo.hasExtension("GL_CHROMIUM_bind_uniform_location");
 #else
     fBindUniformLocationSupport = false;
 #endif
 
+    if (ctxInfo.hasExtension("GL_OES_EGL_image_external")) {
+        if (ctxInfo.glslGeneration() == k110_GrGLSLGeneration) {
+            fExternalTextureSupport = true;
+        } else if (ctxInfo.hasExtension("GL_OES_EGL_image_external_essl3") ||
+                   ctxInfo.hasExtension("OES_EGL_image_external_essl3")) {
+            // At least one driver has been found that has this extension without the "GL_" prefix.
+            fExternalTextureSupport = true;
+        }
+    }
+
 #ifdef SK_BUILD_FOR_WIN
     // We're assuming that on Windows Chromium we're using ANGLE.
     bool isANGLE = kANGLE_GrGLDriver == ctxInfo.driver() ||
                    kChromium_GrGLDriver == ctxInfo.driver();
     // Angle has slow read/write pixel paths for 32bit RGBA (but fast for BGRA). 
     fRGBA8888PixelsOpsAreSlow = isANGLE;
     // On DX9 ANGLE reading a partial FBO is slow. TODO: Check whether this is still true and
     // check DX11 ANGLE.
     fPartialFBOReadIsSlow = isANGLE;
 #endif
@@ skipping 309 matching lines @@
         kGLES_GrGLStandard != standard &&
         (ctxInfo.glslGeneration() >= k150_GrGLSLGeneration ||
          ctxInfo.hasExtension("GL_ARB_fragment_coord_conventions"))) {
         glslCaps->fFragCoordConventionsExtensionString = "GL_ARB_fragment_coord_conventions";
     }
 
     if (kGLES_GrGLStandard == standard) {
         glslCaps->fSecondaryOutputExtensionString = "GL_EXT_blend_func_extended";
     }
 
+    if (fExternalTextureSupport) {
+        if (ctxInfo.glslGeneration() == k110_GrGLSLGeneration) {
+            glslCaps->fExternalTextureExtensionString = "GL_OES_EGL_image_external";
+        } else {
+            glslCaps->fExternalTextureExtensionString = "GL_OES_EGL_image_external_essl3";
+        }
+    }
+
     // The Tegra3 compiler will sometimes never return if we have min(abs(x), 1.0), so we must do
     // the abs first in a separate expression.
     if (kTegra3_GrGLRenderer == ctxInfo.renderer()) {
         glslCaps->fCanUseMinAndAbsTogether = false;
     }
 
-    // On Intel GPU there is an issue where it reads the second arguement to atan "- %s.x" as an int
+    // On Intel GPU there is an issue where it reads the second argument to atan "- %s.x" as an int
     // thus must us -1.0 * %s.x to work correctly
     if (kIntel_GrGLVendor == ctxInfo.vendor()) {
         glslCaps->fMustForceNegatedAtanParamToFloat = true;
     }
 }
 
 bool GrGLCaps::hasPathRenderingSupport(const GrGLContextInfo& ctxInfo, const GrGLInterface* gli) {
     bool hasChromiumPathRendering = ctxInfo.hasExtension("GL_CHROMIUM_path_rendering");
 
     if (!(ctxInfo.hasExtension("GL_NV_path_rendering") || hasChromiumPathRendering)) {
@@ skipping 707 matching lines @@
     glslCaps->fConfigSwizzle[kR11_EAC_GrPixelConfig] = "rrrr";
     glslCaps->fConfigSwizzle[kASTC_12x12_GrPixelConfig] = "rgba";
     glslCaps->fConfigSwizzle[kRGBA_float_GrPixelConfig] = "rgba";
     glslCaps->fConfigSwizzle[kRGBA_half_GrPixelConfig] = "rgba";
 
 }
 
 void GrGLCaps::onApplyOptionsOverrides(const GrContextOptions& options) {}