Don't use gl_FragCoord on legacy Tegra hardware

Bug: skia:7413
Bug: skia:7757
Change-Id: I588c49409fd630f4c15546d8be64fb46c87db3c3
Reviewed-on: https://skia-review.googlesource.com/117007
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>

1 files changed, 15 insertions, 8 deletions

diff --git a/src/gpu/gl/GrGLUtil.cpp b/src/gpu/gl/GrGLUtil.cpp
index 3de894db82..985bd4e304 100644
--- a/src/gpu/gl/GrGLUtil.cpp
+++ b/src/gpu/gl/GrGLUtil.cpp
@@ -284,12 +284,15 @@ static bool is_renderer_angle(const char* rendererString) {
     return 0 == strncmp(rendererString, kHeader, kHeaderLength);
 }
 
-GrGLRenderer GrGLGetRendererFromString(const char* rendererString) {
+GrGLRenderer GrGLGetRendererFromStrings(const char* rendererString, const char* extensionString) {
     if (rendererString) {
-        if (0 == strcmp(rendererString, "NVIDIA Tegra 3")) {
-            return kTegra3_GrGLRenderer;
-        } else if (0 == strcmp(rendererString, "NVIDIA Tegra")) {
-            return kTegra2_GrGLRenderer;
+        static const char kTegraStr[] = "NVIDIA Tegra";
+        if (0 == strncmp(rendererString, kTegraStr, SK_ARRAY_COUNT(kTegraStr) - 1)) {
+            // Tegra strings are not very descriptive. We distinguish between the modern and legacy
+            // architectures by the presence of NV_path_rendering.
+            return (extensionString && strstr(extensionString, "GL_NV_path_rendering"))
+                           ? kTegra_GrGLRenderer
+                           : kTegra_PreK1_GrGLRenderer;
         }
         int lastDigit;
         int n = sscanf(rendererString, "PowerVR SGX 54%d", &lastDigit);
@@ -462,9 +465,13 @@ GrGLVendor GrGLGetVendor(const GrGLInterface* gl) {
 }
 
 GrGLRenderer GrGLGetRenderer(const GrGLInterface* gl) {
-    const GrGLubyte* v;
-    GR_GL_CALL_RET(gl, v, GetString(GR_GL_RENDERER));
-    return GrGLGetRendererFromString((const char*) v);
+    const GrGLubyte* rendererString;
+    GR_GL_CALL_RET(gl, rendererString, GetString(GR_GL_RENDERER));
+
+    const GrGLubyte* extensionString;
+    GR_GL_CALL_RET(gl, extensionString, GetString(GR_GL_EXTENSIONS));
+
+    return GrGLGetRendererFromStrings((const char*) rendererString, (const char*) extensionString);
 }
 
 GrGLenum GrToGLStencilFunc(GrStencilTest test) {