Vulkan: Optimize color invalidates

By not flushing the render pass when there is an invalidate.

Previously, the tracking of invalidation, write to attachments,
management of load/store ops, and whether image contents are defined or
not have all been unified between color and depth/stencil images.

As such, it is possible to not close the render pass when a color image
is invalidated just as is not done for depth/stencil images.  Together
with the optimization to resolve attachments [1], it is now finally
possible to efficiently do MSAA rendering with ANGLE.

Note that the optimization to use resolve attachments for depth/stencil
is not yet implemented.  For color only, the perf test added in [2]
shows the following improvement on Pixel 6:

- Single sampled rendering: ~2.73ms
- Resolve + invalidate (before optimizations): ~3.54ms
- Resolve + invalidate (after this change): ~2.85ms

[1]: https://chromium-review.googlesource.com/c/angle/angle/+/5388492
[2]: https://chromium-review.googlesource.com/c/angle/angle/+/5392548

Bug: angleproject:7551
Change-Id: I008adf9f53df97ab464b0a0399f0b312bf4d0d3f
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5391905
Reviewed-by: Yuxin Hu <[email protected]>
Reviewed-by: Amirali Abdolrashidi <[email protected]>
Commit-Queue: Shahbaz Youssefi <[email protected]>

src/libANGLE/renderer/vulkan/FramebufferVk.cpp

@@ -2094,18 +2094,6 @@ angle::Result FramebufferVk::invalidateImpl(ContextVk *contextVk,
                     dsState, invalidateArea);
             }
         }
-        if (invalidateColorBuffers.any())
-        {
-            // Only end the render pass if invalidating at least one color buffer.  Do not end the
-            // render pass if only the depth and/or stencil buffer is invalidated.  At least one
-            // application invalidates those every frame, disables depth, and then continues to
-            // draw only to the color buffer.
-            //
-            // Since we are not aware of any application that invalidates a color buffer and
-            // continues to draw to it, we leave that unoptimized.
-            ANGLE_TRY(contextVk->flushCommandsAndEndRenderPass(
-                RenderPassClosureReason::ColorBufferInvalidate));
-        }
     }
 
     return angle::Result::Continue;

src/tests/gl_tests/VulkanPerformanceCounterTest.cpp

@@ -1558,6 +1558,12 @@ TEST_P(VulkanPerformanceCounterTest_ES31, MultisampleResolveWithBlit)
 // Test resolving a multisampled texture with blit and then invalidate the msaa buffer
 TEST_P(VulkanPerformanceCounterTest_ES31, ResolveToFBOWithInvalidate)
 {
+    angle::VulkanPerfCounters expected;
+
+    // Expect rpCount+1, color(Clears+0, Loads+0, LoadNones+0, Stores+1, StoreNones+0)
+    setExpectedCountersForColorOps(getPerfCounters(), 1, 0, 0, 0, 1, 0, &expected);
+    expected.colorAttachmentResolves = getPerfCounters().colorAttachmentResolves + 1;
+
     constexpr int kWindowWidth  = 4;
     constexpr int kWindowHeight = 4;
     GLTexture resolveTexture;
@@ -1592,11 +1598,13 @@ TEST_P(VulkanPerformanceCounterTest_ES31, ResolveToFBOWithInvalidate)
     glInvalidateFramebuffer(GL_READ_FRAMEBUFFER, 1, &attachment);
     glBindFramebuffer(GL_FRAMEBUFFER, resolveFBO);
 
-    EXPECT_EQ(getPerfCounters().colorStoreOpStores, 1u);
-
     // Top-left pixels should be all red.
     EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);
 
+    EXPECT_EQ(expected.renderPasses, getPerfCounters().renderPasses);
+    EXPECT_EQ(expected.colorAttachmentResolves, getPerfCounters().colorAttachmentResolves);
+    EXPECT_COLOR_OP_COUNTERS(getPerfCounters(), expected);
+
     ASSERT_GL_NO_ERROR();
 }
 
@@ -1722,14 +1730,11 @@ void main()
         ASSERT_GL_NO_ERROR();
 
         EXPECT_EQ(expected.renderPasses, getPerfCounters().renderPasses);
-        // Currently not optimized well.  http://anglebug.com/7551
         EXPECT_EQ(expected.colorAttachmentResolves, getPerfCounters().colorAttachmentResolves);
         EXPECT_COLOR_OP_COUNTERS(getPerfCounters(), expected);
     };
 
-    // TODO: currently, the Vulkan backend flushes the render pass after the first invalidate, so
-    // the second resolve doesn't get a chance to be optimized.  http://anglebug.com/7551
-    // test(GLColor::blue, GLColor::yellow, Invalidate::AfterEachResolve);
+    test(GLColor::blue, GLColor::yellow, Invalidate::AfterEachResolve);
     test(GLColor::cyan, GLColor::magenta, Invalidate::AllAtEnd);
 }
 
@@ -6756,6 +6761,79 @@ TEST_P(VulkanPerformanceCounterTest, InvalidateThenRepeatedClearThenReadbackThen
     EXPECT_COLOR_OP_COUNTERS(getPerfCounters(), expected);
 }
 
+// Test that draw after invalidate restores the contents of the color image.
+TEST_P(VulkanPerformanceCounterTest, InvalidateThenDraw)
+{
+    ANGLE_SKIP_TEST_IF(!IsGLExtensionEnabled(kPerfMonitorExtensionName));
+
+    angle::VulkanPerfCounters expected;
+
+    constexpr GLsizei kSize = 2;
+
+    GLTexture tex;
+    glBindTexture(GL_TEXTURE_2D, tex);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, kSize, kSize, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
+
+    GLFramebuffer fbo;
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tex, 0);
+
+    // Expect rpCount+1, color(Clears+0, Loads+0, LoadNones+0, Stores+1, StoreNones+0)
+    setExpectedCountersForColorOps(getPerfCounters(), 1, 0, 0, 0, 1, 0, &expected);
+
+    ANGLE_GL_PROGRAM(blue, essl1_shaders::vs::Simple(), essl1_shaders::fs::Blue());
+    drawQuad(blue, essl1_shaders::PositionAttrib(), 0);
+
+    // Invalidate it such that the contents are marked as undefined
+    const GLenum discards[] = {GL_COLOR_ATTACHMENT0};
+    glInvalidateFramebuffer(GL_FRAMEBUFFER, 1, discards);
+
+    // Draw again.
+    ANGLE_GL_PROGRAM(green, essl1_shaders::vs::Simple(), essl1_shaders::fs::Green());
+    drawQuad(green, essl1_shaders::PositionAttrib(), 0);
+
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
+    EXPECT_COLOR_OP_COUNTERS(getPerfCounters(), expected);
+}
+
+// Test that masked draw after invalidate does NOT restore the contents of the color image.
+TEST_P(VulkanPerformanceCounterTest, InvalidateThenMaskedDraw)
+{
+    ANGLE_SKIP_TEST_IF(!IsGLExtensionEnabled(kPerfMonitorExtensionName));
+
+    angle::VulkanPerfCounters expected;
+
+    constexpr GLsizei kSize = 2;
+
+    GLTexture tex;
+    glBindTexture(GL_TEXTURE_2D, tex);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, kSize, kSize, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
+
+    GLFramebuffer fbo;
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tex, 0);
+
+    // Expect rpCount+1, color(Clears+0, Loads+0, LoadNones+0, Stores+0, StoreNones+0)
+    setExpectedCountersForColorOps(getPerfCounters(), 1, 0, 0, 0, 0, 0, &expected);
+
+    ANGLE_GL_PROGRAM(blue, essl1_shaders::vs::Simple(), essl1_shaders::fs::Blue());
+    drawQuad(blue, essl1_shaders::PositionAttrib(), 0);
+
+    // Invalidate it such that the contents are marked as undefined
+    const GLenum discards[] = {GL_COLOR_ATTACHMENT0};
+    glInvalidateFramebuffer(GL_FRAMEBUFFER, 1, discards);
+
+    // Draw again.
+    glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
+    ANGLE_GL_PROGRAM(green, essl1_shaders::vs::Simple(), essl1_shaders::fs::Green());
+    drawQuad(green, essl1_shaders::PositionAttrib(), 0);
+
+    // Break the render pass
+    glFinish();
+
+    EXPECT_COLOR_OP_COUNTERS(getPerfCounters(), expected);
+}
+
 // Tests that the submission counters count the implicit submission in eglSwapBuffers().
 TEST_P(VulkanPerformanceCounterTest, VerifySubmitCountersForSwapBuffer)
 {