commit 4c18b62a004599d5a36ab7d772302dff2be91a3b
author csmartdalton <csmartdalton@google.com> Fri Jul 29 12:19:28 2016 -0700
committer Commit bot <commit-bot@chromium.org> Fri Jul 29 12:19:28 2016 -0700
tree 4b97320146b07dc9ccfdaae3f42e2221dda77ded
parent 848904e5b356ac427ccf68f8a39837e52fa61059

Add ES 3.0 fallback for instanced rendering

Adds the ability for GLInstancedRendering to use
glDrawElementsInstanced when glDrawElementsIndirect is not supported.

The only remaining 3.1 dependency now is EXT_texture_buffer.

Also moves the cap for glDraw*Instanced out of GrCaps and into
GrGLCaps.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2193303002

Review-Url: https://codereview.chromium.org/2193303002

src/gpu/gl/GrGLCaps.cpp

diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index 653b5ca..5a1a5b4 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -38,6 +38,7 @@
     fDirectStateAccessSupport = false;
     fDebugSupport = false;
     fES2CompatibilitySupport = false;
+    fDrawInstancedSupport = false;
     fDrawIndirectSupport = false;
     fMultiDrawIndirectSupport = false;
     fBaseInstanceSupport = false;
@@ -502,12 +503,12 @@
     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"));
@@ -518,12 +519,15 @@
                                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);
@@ -1105,6 +1109,7 @@
     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"));