Vulkan: Test render and sample the same texture but with different LOD
This simulates aztec ruin's usage. This works properly on native OpenGL
but generates validation error on vulkan backend and renders incorrect
as well.
Bug: b/175584609
Test: FramebufferTest_ES3.SampleFromAttachedTextureWithDifferentLOD
Change-Id: I402c205a1b625669cae29ee201dddd144e0dfbde
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2743797
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>
Commit-Queue: Charlie Lao <cclao@google.com>
diff --git a/src/tests/gl_tests/FramebufferTest.cpp b/src/tests/gl_tests/FramebufferTest.cpp
index 7cf1d8d..024b198 100644
--- a/src/tests/gl_tests/FramebufferTest.cpp
+++ b/src/tests/gl_tests/FramebufferTest.cpp
@@ -2468,6 +2468,76 @@
EXPECT_PIXEL_COLOR_EQ(kSize - 1, kSize - 1, GLColor::blue);
}
+// Tests that we can support a color texture also attached to the color attachment but
+// with different LOD. From GLES3.0 spec section 4.4.3.2, if min_filter is GL_NEAREST_MIPMAP_NEAREST
+// and the lod is within the [base_level, max_level] range, and it is possible to sample from a LOD
+// that is rendering to then it does form a feedback loop. But if it is using textureLOD to
+// explicitly fetching texture on different LOD, there is no loop and should still work. Aztec_ruins
+// (https://issuetracker.google.com/175584609) is doing exactly this.
+TEST_P(FramebufferTest_ES3, SampleFromAttachedTextureWithDifferentLOD)
+{
+ // TODO: https://issuetracker.google.com/175584609
+ ANGLE_SKIP_TEST_IF(IsVulkan() || IsWindows());
+
+ constexpr GLuint kLevel0Size = 4;
+ constexpr GLuint kLevel1Size = kLevel0Size / 2;
+ constexpr GLuint kLevel2Size = kLevel1Size / 2;
+ std::array<GLColor, kLevel0Size * kLevel0Size> gData;
+
+ GLTexture colorTexture;
+ glBindTexture(GL_TEXTURE_2D, colorTexture);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+ glTexStorage2D(GL_TEXTURE_2D, 3, GL_RGBA8, kLevel0Size, kLevel0Size);
+ gData.fill(GLColor::red);
+ glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, kLevel0Size, kLevel0Size, GL_RGBA, GL_UNSIGNED_BYTE,
+ gData.data());
+ gData.fill(GLColor::green);
+ glTexSubImage2D(GL_TEXTURE_2D, 1, 0, 0, kLevel1Size, kLevel1Size, GL_RGBA, GL_UNSIGNED_BYTE,
+ gData.data());
+ gData.fill(GLColor::blue);
+ glTexSubImage2D(GL_TEXTURE_2D, 2, 0, 0, kLevel2Size, kLevel2Size, GL_RGBA, GL_UNSIGNED_BYTE,
+ gData.data());
+
+ // Attach level 1 to a FBO
+ GLFramebuffer framebuffer;
+ glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
+ glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colorTexture, 1);
+ ASSERT_GL_NO_ERROR();
+ ASSERT_GL_FRAMEBUFFER_COMPLETE(GL_FRAMEBUFFER);
+
+ // Render to FBO with color texture level 1 and textureLod from level 0.
+ const GLenum discard[] = {GL_COLOR_ATTACHMENT0};
+ glInvalidateFramebuffer(GL_FRAMEBUFFER, 1, discard);
+ glViewport(0, 0, kLevel1Size, kLevel1Size);
+ glScissor(0, 0, kLevel1Size, kLevel1Size);
+ glEnable(GL_CULL_FACE);
+ glCullFace(GL_BACK);
+ glDisable(GL_BLEND);
+ glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
+ glActiveTexture(GL_TEXTURE0);
+ glBindTexture(GL_TEXTURE_2D, colorTexture);
+
+ ANGLE_GL_PROGRAM(program, essl3_shaders::vs::Texture2DLod(), essl3_shaders::fs::Texture2DLod());
+ glUseProgram(program);
+ GLint textureLoc = glGetUniformLocation(program, essl3_shaders::Texture2DUniform());
+ GLint lodLoc = glGetUniformLocation(program, essl3_shaders::LodUniform());
+ ASSERT_NE(-1, textureLoc);
+ ASSERT_NE(-1, lodLoc);
+ glUniform1i(textureLoc, 0); // texture unit 0
+ glUniform1f(lodLoc, 0); // with Lod=0
+ drawQuad(program, essl3_shaders::PositionAttrib(), 0.5f);
+
+ glDisable(GL_CULL_FACE);
+ glDisable(GL_DEPTH_TEST);
+ glDisable(GL_BLEND);
+ glDisable(GL_SCISSOR_TEST);
+ glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
+
+ ASSERT_GL_NO_ERROR();
+ EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);
+}
+
// Covers a bug in ANGLE's Vulkan back-end. Our VkFramebuffer cache would in some cases forget to
// check the draw states when computing a cache key.
TEST_P(FramebufferTest_ES3, DisabledAttachmentRedefinition)
