Culling and FrontFace: verify the framebuffer coordinate

This patch is to verify the framebuffer coordinate in Dawn (and WebGPU).
It shows that gl_FragCoord(0, 0) is at the top left.

BUG=dawn:43
TEST=dawn_end2end_tests

Change-Id: Ifd16488169c986d0c2c85eb92283c69e70ad33ae
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/8780
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Yunchao He <yunchao.he@intel.com>
This commit is contained in:
Yunchao He 2019-07-11 15:55:45 +00:00 committed by Commit Bot service account
parent 002395300f
commit 110700304f

View File

@ -39,11 +39,14 @@ class CullingTest : public DawnTest {
pipelineDescriptor.cVertexStage.module =
utils::CreateShaderModule(device, dawn::ShaderStage::Vertex, vs);
// gl_FragCoord of pixel(x, y) in framebuffer coordinate is (x + 0.5, y + 0.5). And we use
// RGBA8 format for the back buffer. So (gl_FragCoord.xy - vec2(0.5)) / 255 in shader code
// will make the pixel's R and G channels exactly equal to the pixel's x and y coordinates.
const char* fs =
"#version 450\n"
"layout(location = 0) out vec4 fragColor;"
"void main() {\n"
" fragColor = vec4(1.0, 0.0, 0.0, 1.0);\n"
" fragColor = vec4((gl_FragCoord.xy - vec2(0.5)) / 255, 0.0, 1.0);\n"
"}\n";
pipelineDescriptor.cFragmentStage.module =
utils::CreateShaderModule(device, dawn::ShaderStage::Fragment, fs);
@ -75,7 +78,7 @@ class CullingTest : public DawnTest {
dawn::Texture colorTexture = Create2DTextureForTest(dawn::TextureFormat::RGBA8Unorm);
utils::ComboRenderPassDescriptor renderPassDescriptor({colorTexture.CreateDefaultView()});
renderPassDescriptor.cColorAttachmentsInfoPtr[0]->clearColor = {0.0, 1.0, 0.0, 1.0};
renderPassDescriptor.cColorAttachmentsInfoPtr[0]->clearColor = {0.0, 0.0, 1.0, 1.0};
renderPassDescriptor.cColorAttachmentsInfoPtr[0]->loadOp = dawn::LoadOp::Clear;
dawn::CommandEncoder commandEncoder = device.CreateCommandEncoder();
@ -87,14 +90,16 @@ class CullingTest : public DawnTest {
dawn::Queue queue = device.CreateQueue();
queue.Submit(1, &commandBuffer);
constexpr RGBA8 kDrawingColor = RGBA8(255, 0, 0, 255);
constexpr RGBA8 kBackgroundColor = RGBA8(0, 255, 0, 255);
constexpr RGBA8 kTopLeftColor = RGBA8(0, 0, 0, 255);
constexpr RGBA8 kBottomRightColor = RGBA8(3, 3, 0, 255);
constexpr RGBA8 kBackgroundColor = RGBA8(0, 0, 255, 255);
RGBA8 kCCWTriangleColor = isCCWTriangleCulled ? kBackgroundColor : kDrawingColor;
EXPECT_PIXEL_RGBA8_EQ(kCCWTriangleColor, colorTexture, 0, 0);
RGBA8 kCCWTriangleTopLeftColor = isCCWTriangleCulled ? kBackgroundColor : kTopLeftColor;
EXPECT_PIXEL_RGBA8_EQ(kCCWTriangleTopLeftColor, colorTexture, 0, 0);
RGBA8 kCWTriangleColor = isCWTriangleCulled ? kBackgroundColor : kDrawingColor;
EXPECT_PIXEL_RGBA8_EQ(kCWTriangleColor, colorTexture, kSize - 1, kSize - 1);
RGBA8 kCWTriangleBottomRightColor =
isCWTriangleCulled ? kBackgroundColor : kBottomRightColor;
EXPECT_PIXEL_RGBA8_EQ(kCWTriangleBottomRightColor, colorTexture, kSize - 1, kSize - 1);
}
static constexpr uint32_t kSize = 4;