Fix issue with unused mips.

The bug was

1) Create a texture with N mips (4x4, 2x2, 1x1)
2) Then update the texture to use less than N mips (2x2, 1x1) etc.

The code would incorrectly look at the unused mips in determining
whether or not the texture was renderable.

TEST=unit test
BUG=97207

R=zmo@chromium.org


Review URL: http://codereview.chromium.org/8041048

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@102967 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 36 insertions, 9 deletions

diff --git a/gpu/command_buffer/service/texture_manager.cc b/gpu/command_buffer/service/texture_manager.cc
index 02f5ab9..134308d 100644
--- a/gpu/command_buffer/service/texture_manager.cc
+++ b/gpu/command_buffer/service/texture_manager.cc
@@ -343,11 +343,10 @@ void TextureManager::TextureInfo::Update(const FeatureInfo* feature_info) {
 
   // Update texture_complete and cube_complete status.
   const TextureInfo::LevelInfo& first_face = level_infos_[0][0];
+  int levels_needed = ComputeMipMapCount(
+      first_face.width, first_face.height, first_face.depth);
   texture_complete_ =
-      (max_level_set_ == ComputeMipMapCount(first_face.width,
-                                            first_face.height,
-                                            first_face.depth) - 1) &&
-      max_level_set_ >= 0;
+      max_level_set_ >= (levels_needed - 1) && max_level_set_ >= 0;
   cube_complete_ = (level_infos_.size() == 6) &&
                    (first_face.width == first_face.height);
   if (first_face.width == 0 || first_face.height == 0) {
@@ -381,7 +380,7 @@ void TextureManager::TextureInfo::Update(const FeatureInfo* feature_info) {
     GLsizei width = level0.width;
     GLsizei height = level0.height;
     GLsizei depth = level0.depth;
-    for (GLint jj = 1; jj <= max_level_set_; ++jj) {
+    for (GLint jj = 1; jj < levels_needed; ++jj) {
       // compute required size for mip.
       width = std::max(1, width >> 1);
       height = std::max(1, height >> 1);
diff --git a/gpu/command_buffer/service/texture_manager_unittest.cc b/gpu/command_buffer/service/texture_manager_unittest.cc
index 6800481..cf33e72 100644
--- a/gpu/command_buffer/service/texture_manager_unittest.cc
+++ b/gpu/command_buffer/service/texture_manager_unittest.cc
@@ -377,9 +377,37 @@ TEST_F(TextureInfoTest, POT2D) {
   EXPECT_TRUE(info_->CanGenerateMipmaps(&feature_info_));
   // Make mips.
   EXPECT_TRUE(manager_.MarkMipmapsGenerated(&feature_info_, info_));
-  EXPECT_FALSE(info_->CanRender(&feature_info_));
-  EXPECT_FALSE(info_->texture_complete());
-  EXPECT_TRUE(manager_.HaveUnrenderableTextures());
+  EXPECT_TRUE(info_->CanRender(&feature_info_));
+  EXPECT_TRUE(info_->texture_complete());
+  EXPECT_FALSE(manager_.HaveUnrenderableTextures());
+}
+
+TEST_F(TextureInfoTest, UnusedMips) {
+  manager_.SetInfoTarget(info_, GL_TEXTURE_2D);
+  EXPECT_EQ(static_cast<GLenum>(GL_TEXTURE_2D), info_->target());
+  // Set level zero to large size.
+  manager_.SetLevelInfo(&feature_info_, info_,
+      GL_TEXTURE_2D, 0, GL_RGBA, 4, 4, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE);
+  EXPECT_TRUE(manager_.MarkMipmapsGenerated(&feature_info_, info_));
+  EXPECT_FALSE(info_->npot());
+  EXPECT_TRUE(info_->texture_complete());
+  EXPECT_TRUE(info_->CanRender(&feature_info_));
+  EXPECT_FALSE(manager_.HaveUnrenderableTextures());
+  // Set level zero to large smaller (levels unused mips)
+  manager_.SetLevelInfo(&feature_info_, info_,
+      GL_TEXTURE_2D, 0, GL_RGBA, 2, 2, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE);
+  EXPECT_TRUE(manager_.MarkMipmapsGenerated(&feature_info_, info_));
+  EXPECT_FALSE(info_->npot());
+  EXPECT_TRUE(info_->texture_complete());
+  EXPECT_TRUE(info_->CanRender(&feature_info_));
+  EXPECT_FALSE(manager_.HaveUnrenderableTextures());
+  // Set an unused level to some size
+  manager_.SetLevelInfo(&feature_info_, info_,
+      GL_TEXTURE_2D, 4, GL_RGBA, 16, 16, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE);
+  EXPECT_FALSE(info_->npot());
+  EXPECT_TRUE(info_->texture_complete());
+  EXPECT_TRUE(info_->CanRender(&feature_info_));
+  EXPECT_FALSE(manager_.HaveUnrenderableTextures());
 }
 
 TEST_F(TextureInfoTest, NPOT2D) {
@@ -522,7 +550,7 @@ TEST_F(TextureInfoTest, POTCubeMap) {
   EXPECT_TRUE(info_->CanGenerateMipmaps(&feature_info_));
   // Make mips.
   EXPECT_TRUE(manager_.MarkMipmapsGenerated(&feature_info_, info_));
-  EXPECT_FALSE(info_->texture_complete());
+  EXPECT_TRUE(info_->texture_complete());
   EXPECT_TRUE(info_->cube_complete());
 }