Add detection of mip support

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 267 matching lines @@
     }
 
     if (kDesktop_GrGLBinding == binding) {
         fBufferLockSupport = true; // we require VBO support and the desktop VBO extension includes
                                    // glMapBuffer.
     } else {
         fBufferLockSupport = ctxInfo.hasExtension("GL_OES_mapbuffer");
     }
 
     if (kDesktop_GrGLBinding == binding) {
-        if (ctxInfo.version() >= GR_GL_VER(2,0) ||
-            ctxInfo.hasExtension("GL_ARB_texture_non_power_of_two")) {
-            fNPOTTextureTileSupport = true;
-        } else {
-            fNPOTTextureTileSupport = false;
-        }
+        SkASSERT(ctxInfo.version() >= GR_GL_VER(2,0) ||
+                 ctxInfo.hasExtension("GL_ARB_texture_non_power_of_two"));
+        fNPOTTextureTileSupport = true;
+        fMipMapSupport = true;
     } else {
         // Unextended ES2 supports NPOT textures with clamp_to_edge and non-mip filters only
         // ES3 has no limitations.
         fNPOTTextureTileSupport = ctxInfo.version() >= GR_GL_VER(3,0) ||
                                   ctxInfo.hasExtension("GL_OES_texture_npot");
+        // ES2 supports MIP mapping for POT textures but our caps don't allow for limited MIP
+        // support. The OES extension or ES 3.0 allow for MIPS on NPOT textures. So, apparently,
+        // does the undocumented GL_IMG_texture_npot extension. This extension does not seem to
+        // to alllow arbitrary wrap modes, however.
+        fMipMapSupport = fNPOTTextureTileSupport || ctxInfo.hasExtension("GL_IMG_texture_npot");
     }
 
     fHWAALineSupport = (kDesktop_GrGLBinding == binding);
 
     GR_GL_GetIntegerv(gli, GR_GL_MAX_TEXTURE_SIZE, &fMaxTextureSize);
     GR_GL_GetIntegerv(gli, GR_GL_MAX_RENDERBUFFER_SIZE, &fMaxRenderTargetSize);
     // Our render targets are always created with textures as the color
     // attachment, hence this min:
     fMaxRenderTargetSize = GrMin(fMaxTextureSize, fMaxRenderTargetSize);
 
@@ skipping 342 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("Discard FrameBuffer support: %s\n", (fDiscardFBSupport ? "YES" : "NO"));
     r.appendf("Full screen clear is free: %s\n", (fFullClearIsFree ? "YES" : "NO"));
     return r;
 }