Improve current multisampled renderbuffer/texture support

src/libANGLE/Renderbuffer.cpp

@@ -114,6 +114,14 @@ angle::Result Renderbuffer::setStorageMultisample(const Context *context,
                                                   size_t height)
 {
     ANGLE_TRY(orphanImages(context));
+    // TODO (ianelliott): Ensure that the following spec language is correctly implemented:
+    //
+    //   the resulting value for RENDERBUFFER_SAMPLES is guaranteed to be greater than or equal to
+    //   samples and no more than the next larger sample count supported by the implementation.
+    //
+    // For example, if 2, 4, and 8 samples are supported, and if 5 samples are requested, ANGLE
+    // should use 8 samples, and return 8 when GL_RENDERBUFFER_SAMPLES is queried.
+    // http://anglebug.com/4196
     ANGLE_TRY(
         mImplementation->setStorageMultisample(context, samples, internalformat, width, height));
 

src/libANGLE/Texture.cpp

@@ -1351,6 +1351,10 @@ angle::Result Texture::setStorageMultisample(Context *context,
     ANGLE_TRY(releaseTexImageInternal(context));
     ANGLE_TRY(orphanImages(context));
 
+    // Potentially adjust "samples" to a supported value
+    const TextureCaps &formatCaps = context->getTextureCaps().get(internalFormat);
+    samples                       = formatCaps.getNearestSamples(samples);
+
     ANGLE_TRY(mTexture->setStorageMultisample(context, type, samples, internalFormat, size,
                                               fixedSampleLocations));
 

src/libANGLE/renderer/d3d/d3d11/Framebuffer11.cpp

@@ -406,7 +406,7 @@ angle::Result Framebuffer11::getSamplePosition(const gl::Context *context,
     ASSERT(attachment);
     GLsizei sampleCount = attachment->getSamples();
 
-    d3d11_gl::GetSamplePosition(sampleCount, index, xy);
+    rx::GetSamplePosition(sampleCount, index, xy);
     return angle::Result::Continue;
 }
 

src/libANGLE/renderer/d3d/d3d11/renderer11_utils.cpp

@@ -38,20 +38,6 @@ namespace d3d11_gl
 {
 namespace
 {
-// Standard D3D sample positions from
-// https://msdn.microsoft.com/en-us/library/windows/desktop/ff476218.aspx
-using SamplePositionsArray                                            = std::array<float, 32>;
-static constexpr std::array<SamplePositionsArray, 5> kSamplePositions = {
-    {{{0.5f, 0.5f}},
-     {{0.75f, 0.75f, 0.25f, 0.25f}},
-     {{0.375f, 0.125f, 0.875f, 0.375f, 0.125f, 0.625f, 0.625f, 0.875f}},
-     {{0.5625f, 0.3125f, 0.4375f, 0.6875f, 0.8125f, 0.5625f, 0.3125f, 0.1875f, 0.1875f, 0.8125f,
-       0.0625f, 0.4375f, 0.6875f, 0.9375f, 0.9375f, 0.0625f}},
-     {{0.5625f, 0.5625f, 0.4375f, 0.3125f, 0.3125f, 0.625f,  0.75f,   0.4375f,
-       0.1875f, 0.375f,  0.625f,  0.8125f, 0.8125f, 0.6875f, 0.6875f, 0.1875f,
-       0.375f,  0.875f,  0.5f,    0.0625f, 0.25f,   0.125f,  0.125f,  0.75f,
-       0.0f,    0.5f,    0.9375f, 0.25f,   0.875f,  0.9375f, 0.0625f, 0.0f}}}};
-
 // TODO(xinghua.cao@intel.com): Get a more accurate limit.
 static D3D_FEATURE_LEVEL kMinimumFeatureLevelForES31 = D3D_FEATURE_LEVEL_11_0;
 
@@ -1698,16 +1684,6 @@ void GenerateCaps(ID3D11Device *device,
 #endif
 }
 
-void GetSamplePosition(GLsizei sampleCount, size_t index, GLfloat *xy)
-{
-    size_t indexKey = static_cast<size_t>(ceil(log2(sampleCount)));
-    ASSERT(indexKey < kSamplePositions.size() &&
-           (2 * index + 1) < kSamplePositions[indexKey].size());
-
-    xy[0] = kSamplePositions[indexKey][2 * index];
-    xy[1] = kSamplePositions[indexKey][2 * index + 1];
-}
-
 }  // namespace d3d11_gl
 
 namespace gl_d3d11

src/libANGLE/renderer/d3d/d3d11/renderer11_utils.h

@@ -81,8 +81,6 @@ void GenerateCaps(ID3D11Device *device,
                   gl::Extensions *extensions,
                   gl::Limitations *limitations);
 
-void GetSamplePosition(GLsizei sampleCount, size_t index, GLfloat *xy);
-
 D3D_FEATURE_LEVEL GetMinimumFeatureLevelForES31();
 
 }  // namespace d3d11_gl

src/libANGLE/renderer/renderer_utils.cpp

@@ -29,6 +29,25 @@ namespace rx
 
 namespace
 {
+// Both D3D and Vulkan support the same set of standard sample positions for 1, 2, 4, 8, and 16
+// samples.  See:
+//
+// - https://msdn.microsoft.com/en-us/library/windows/desktop/ff476218.aspx
+//
+// -
+// https://www.khronos.org/registry/vulkan/specs/1.1-extensions/html/vkspec.html#primsrast-multisampling
+using SamplePositionsArray                                     = std::array<float, 32>;
+constexpr std::array<SamplePositionsArray, 5> kSamplePositions = {
+    {{{0.5f, 0.5f}},
+     {{0.75f, 0.75f, 0.25f, 0.25f}},
+     {{0.375f, 0.125f, 0.875f, 0.375f, 0.125f, 0.625f, 0.625f, 0.875f}},
+     {{0.5625f, 0.3125f, 0.4375f, 0.6875f, 0.8125f, 0.5625f, 0.3125f, 0.1875f, 0.1875f, 0.8125f,
+       0.0625f, 0.4375f, 0.6875f, 0.9375f, 0.9375f, 0.0625f}},
+     {{0.5625f, 0.5625f, 0.4375f, 0.3125f, 0.3125f, 0.625f,  0.75f,   0.4375f,
+       0.1875f, 0.375f,  0.625f,  0.8125f, 0.8125f, 0.6875f, 0.6875f, 0.1875f,
+       0.375f,  0.875f,  0.5f,    0.0625f, 0.25f,   0.125f,  0.125f,  0.75f,
+       0.0f,    0.5f,    0.9375f, 0.25f,   0.875f,  0.9375f, 0.0625f, 0.0f}}}};
+
 void CopyColor(gl::ColorF *color)
 {
     // No-op
@@ -781,4 +800,24 @@ void OverrideFeaturesWithDisplayState(angle::FeatureSetBase *features,
     features->overrideFeatures(state.featureOverridesEnabled, true);
     features->overrideFeatures(state.featureOverridesDisabled, false);
 }
+
+void GetSamplePosition(GLsizei sampleCount, size_t index, GLfloat *xy)
+{
+    if (sampleCount > 16)
+    {
+        // Vulkan (and D3D11) doesn't have standard sample positions for 32 and 64 samples (and no
+        // drivers are known to support that many samples)
+        xy[0] = 0.5f;
+        xy[1] = 0.5f;
+    }
+    else
+    {
+        size_t indexKey = static_cast<size_t>(gl::log2(sampleCount));
+        ASSERT(indexKey < kSamplePositions.size() &&
+               (2 * index + 1) < kSamplePositions[indexKey].size());
+
+        xy[0] = kSamplePositions[indexKey][2 * index];
+        xy[1] = kSamplePositions[indexKey][2 * index + 1];
+    }
+}
 }  // namespace rx

src/libANGLE/renderer/renderer_utils.h

@@ -401,6 +401,8 @@ void CopyLineLoopIndicesWithRestart(GLsizei indexCount, const uint8_t *srcPtr, u
         *(outIndices++) = inIndices[loopStartIndex];
     }
 }
+
+void GetSamplePosition(GLsizei sampleCount, size_t index, GLfloat *xy);
 }  // namespace rx
 
 #endif  // LIBANGLE_RENDERER_RENDERER_UTILS_H_

src/tests/gl_tests/FramebufferTest.cpp

@@ -889,13 +889,26 @@ TEST_P(FramebufferTest_ES31, IncompleteMultisampleSampleCountMix)
     GLFramebuffer mFramebuffer;
     glBindFramebuffer(GL_FRAMEBUFFER, mFramebuffer.get());
 
+    // Lookup the supported number of sample counts (rely on fact that ANGLE uses the same set of
+    // sample counts for textures and renderbuffers)
+    GLint numSampleCounts = 0;
+    std::vector<GLint> sampleCounts;
+    GLsizei queryBufferSize = 1;
+    glGetInternalformativ(GL_TEXTURE_2D_MULTISAMPLE, GL_RGBA8, GL_NUM_SAMPLE_COUNTS,
+                          queryBufferSize, &numSampleCounts);
+    ANGLE_SKIP_TEST_IF((numSampleCounts < 2));
+    sampleCounts.resize(numSampleCounts);
+    queryBufferSize = numSampleCounts;
+    glGetInternalformativ(GL_TEXTURE_2D_MULTISAMPLE, GL_RGBA8, GL_SAMPLES, queryBufferSize,
+                          sampleCounts.data());
+
     GLTexture mTexture;
     glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, mTexture.get());
-    glTexStorage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 1, GL_RGBA8, 1, 1, true);
+    glTexStorage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, sampleCounts[0], GL_RGBA8, 1, 1, true);
 
     GLRenderbuffer mRenderbuffer;
     glBindRenderbuffer(GL_RENDERBUFFER, mRenderbuffer.get());
-    glRenderbufferStorageMultisample(GL_RENDERBUFFER, 2, GL_RGBA8, 1, 1);
+    glRenderbufferStorageMultisample(GL_RENDERBUFFER, sampleCounts[1], GL_RGBA8, 1, 1);
     glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE,
                            mTexture.get(), 0);
     glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_RENDERBUFFER,
@@ -915,11 +928,23 @@ TEST_P(FramebufferTest_ES31, IncompleteMultisampleSampleCountTex)
     GLFramebuffer mFramebuffer;
     glBindFramebuffer(GL_FRAMEBUFFER, mFramebuffer.get());
 
+    // Lookup the supported number of sample counts
+    GLint numSampleCounts = 0;
+    std::vector<GLint> sampleCounts;
+    GLsizei queryBufferSize = 1;
+    glGetInternalformativ(GL_TEXTURE_2D_MULTISAMPLE, GL_RGBA8, GL_NUM_SAMPLE_COUNTS,
+                          queryBufferSize, &numSampleCounts);
+    ANGLE_SKIP_TEST_IF((numSampleCounts < 2));
+    sampleCounts.resize(numSampleCounts);
+    queryBufferSize = numSampleCounts;
+    glGetInternalformativ(GL_TEXTURE_2D_MULTISAMPLE, GL_RGBA8, GL_SAMPLES, queryBufferSize,
+                          sampleCounts.data());
+
     GLTexture mTextures[2];
     glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, mTextures[0].get());
-    glTexStorage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 1, GL_RGBA8, 1, 1, true);
+    glTexStorage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, sampleCounts[0], GL_RGBA8, 1, 1, true);
     glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, mTextures[1].get());
-    glTexStorage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 2, GL_RGBA8, 1, 1, true);
+    glTexStorage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, sampleCounts[1], GL_RGBA8, 1, 1, true);
     glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE,
                            mTextures[0].get(), 0);
     glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D_MULTISAMPLE,

src/tests/gl_tests/RenderbufferMultisampleTest.cpp

@@ -74,5 +74,53 @@ TEST_P(RenderbufferMultisampleTest, IntegerInternalformat)
     }
 }
 
+// Ensure that the following spec language is correctly implemented:
+//
+//   the resulting value for RENDERBUFFER_SAMPLES is guaranteed to be greater than or equal to
+//   samples and no more than the next larger sample count supported by the implementation.
+//
+// For example, if 2, 4, and 8 samples are supported, if 5 samples are requested, ANGLE will
+// use 8 samples, and return 8 when GL_RENDERBUFFER_SAMPLES is queried.
+TEST_P(RenderbufferMultisampleTest, OddSampleCount)
+{
+    ANGLE_SKIP_TEST_IF(getClientMajorVersion() < 3);
+
+    glBindRenderbuffer(GL_RENDERBUFFER, mRenderbuffer);
+    ASSERT_GL_NO_ERROR();
+
+    // Lookup the supported number of sample counts
+    GLint numSampleCounts = 0;
+    std::vector<GLint> sampleCounts;
+    GLsizei queryBufferSize = 1;
+    glGetInternalformativ(GL_RENDERBUFFER, GL_RGBA8, GL_NUM_SAMPLE_COUNTS, queryBufferSize,
+                          &numSampleCounts);
+    ANGLE_SKIP_TEST_IF((numSampleCounts < 2));
+    sampleCounts.resize(numSampleCounts);
+    queryBufferSize = numSampleCounts;
+    glGetInternalformativ(GL_RENDERBUFFER, GL_RGBA8, GL_SAMPLES, queryBufferSize,
+                          sampleCounts.data());
+
+    // Look for two sample counts that are not 1 apart (e.g. 2 and 4).  Request a sample count
+    // that's between those two samples counts (e.g. 3) and ensure that GL_RENDERBUFFER_SAMPLES
+    // is the higher number.
+    for (int i = 1; i < numSampleCounts; i++)
+    {
+        if (sampleCounts[i - 1] > (sampleCounts[i] + 1))
+        {
+            glRenderbufferStorageMultisample(GL_RENDERBUFFER, sampleCounts[i] + 1, GL_RGBA8, 64,
+                                             64);
+            ASSERT_GL_NO_ERROR();
+            GLint renderbufferSamples = 0;
+            glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_SAMPLES,
+                                         &renderbufferSamples);
+            ASSERT_GL_NO_ERROR();
+            // TODO (ianelliott): Uncomment the following line once the implementation is fixed.
+            // http://anglebug.com/4196
+            // EXPECT_EQ(renderbufferSamples, sampleCounts[i-1]);
+            break;
+        }
+    }
+}
+
 ANGLE_INSTANTIATE_TEST_ES3_AND_ES31(RenderbufferMultisampleTest);
 }  // namespace