Ensure we're operating on the correct texture when generating mipmaps.

src/gpu/gl/GrGLGpu.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLGpu.h"
 #include "GrGLBuffer.h"
 #include "GrGLGLSL.h"
@@ skipping 3132 matching lines @@
     // If we created a rt/tex and rendered to it without using a texture and now we're texturing
     // from the rt it will still be the last bound texture, but it needs resolving. So keep this
     // out of the "last != next" check.
     GrGLRenderTarget* texRT = static_cast<GrGLRenderTarget*>(texture->asRenderTarget());
     if (texRT) {
         this->onResolveRenderTarget(texRT);
     }
 
     uint32_t textureID = texture->getUniqueID();
     GrGLenum target = texture->target();
     if (fHWBoundTextureUniqueIDs[unitIdx] != textureID) {

[robertphillips, 2016/04/26 21:31:05]

How is this not getting called ?

[Brian Osman, 2016/04/26 21:35:02]

I don't have a test-case that demonstrates this as a problem (I could attempt to
engineer one, if you'd like). It does seem like it would be quite
difficult/unlikely:

- Draw w/texture A on slot 0, w/o mipmap filter, and texture B on slot 1
- Draw w/texture A on slot 0, with mipmaps

I think that in this case, we'd end up generating mipmaps of B, right?

[robertphillips, 2016/04/26 21:52:47]

I think you're right.

         this->setTextureUnit(unitIdx);
         GL_CALL(BindTexture(target, texture->textureID()));
         fHWBoundTextureUniqueIDs[unitIdx] = textureID;
     }
 
     ResetTimestamp timestamp;
     const GrGLTexture::TexParams& oldTexParams = texture->getCachedTexParams(&timestamp);
     bool setAll = timestamp < this->getResetTimestamp();
     GrGLTexture::TexParams newTexParams;
 
@@ skipping 26 matching lines @@
         if (!this->caps()->mipMapSupport() || GrPixelConfigIsCompressed(texture->config())) {
             filterMode = GrTextureParams::kBilerp_FilterMode;
         }
     }
 
     newTexParams.fMinFilter = glMinFilterModes[filterMode];
     newTexParams.fMagFilter = glMagFilterModes[filterMode];
 
     if (GrTextureParams::kMipMap_FilterMode == filterMode) {
         if (texture->texturePriv().mipMapsAreDirty()) {
+            this->setTextureUnit(unitIdx);
             GL_CALL(GenerateMipmap(target));
             texture->texturePriv().dirtyMipMaps(false);
             texture->texturePriv().setMaxMipMapLevel(SkMipMap::ComputeLevelCount(
                 texture->width(), texture->height()));
         }
     }
 
     newTexParams.fMaxMipMapLevel = texture->texturePriv().maxMipMapLevel();
 
     newTexParams.fWrapS = tile_to_gl_wrap(params.getTileModeX());
@@ skipping 1059 matching lines @@
         if (GR_GL_TEXTURE_EXTERNAL == glTexture->target() ||
             GR_GL_TEXTURE_RECTANGLE == glTexture->target()) {
             copyParams->fFilter = GrTextureParams::kNone_FilterMode;
             copyParams->fWidth = texture->width();
             copyParams->fHeight = texture->height();
             return true;
         }
     }
     return false;
 }