1 // Copyright 2019 The Dawn Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "tests/DawnTest.h"
16
17 #include "utils/ComboRenderPipelineDescriptor.h"
18 #include "utils/WGPUHelpers.h"
19
20 class CullingTest : public DawnTest {
21 protected:
CreatePipelineForTest(wgpu::FrontFace frontFace,wgpu::CullMode cullMode)22 wgpu::RenderPipeline CreatePipelineForTest(wgpu::FrontFace frontFace, wgpu::CullMode cullMode) {
23 utils::ComboRenderPipelineDescriptor pipelineDescriptor;
24
25 // Draw two triangles with different winding orders:
26 // 1. The top-left one is counterclockwise (CCW)
27 // 2. The bottom-right one is clockwise (CW)
28 pipelineDescriptor.vertex.module = utils::CreateShaderModule(device, R"(
29 [[stage(vertex)]]
30 fn main([[builtin(vertex_index)]] VertexIndex : u32) -> [[builtin(position)]] vec4<f32> {
31 var pos = array<vec2<f32>, 6>(
32 vec2<f32>(-1.0, 1.0),
33 vec2<f32>(-1.0, 0.0),
34 vec2<f32>( 0.0, 1.0),
35 vec2<f32>( 0.0, -1.0),
36 vec2<f32>( 1.0, 0.0),
37 vec2<f32>( 1.0, -1.0));
38 return vec4<f32>(pos[VertexIndex], 0.0, 1.0);
39 })");
40
41 // FragCoord of pixel(x, y) in framebuffer coordinate is (x + 0.5, y + 0.5). And we use
42 // RGBA8 format for the back buffer. So (FragCoord.xy - vec2(0.5)) / 255 in shader code
43 // will make the pixel's R and G channels exactly equal to the pixel's x and y coordinates.
44 pipelineDescriptor.cFragment.module = utils::CreateShaderModule(device, R"(
45 [[stage(fragment)]]
46 fn main([[builtin(position)]] FragCoord : vec4<f32>) -> [[location(0)]] vec4<f32> {
47 return vec4<f32>(
48 (FragCoord.xy - vec2<f32>(0.5, 0.5)) / vec2<f32>(255.0, 255.0),
49 0.0, 1.0);
50 })");
51
52 // Set culling mode and front face according to the parameters
53 pipelineDescriptor.primitive.frontFace = frontFace;
54 pipelineDescriptor.primitive.cullMode = cullMode;
55
56 return device.CreateRenderPipeline(&pipelineDescriptor);
57 }
58
Create2DTextureForTest(wgpu::TextureFormat format)59 wgpu::Texture Create2DTextureForTest(wgpu::TextureFormat format) {
60 wgpu::TextureDescriptor textureDescriptor;
61 textureDescriptor.dimension = wgpu::TextureDimension::e2D;
62 textureDescriptor.format = format;
63 textureDescriptor.usage =
64 wgpu::TextureUsage::RenderAttachment | wgpu::TextureUsage::CopySrc;
65 textureDescriptor.mipLevelCount = 1;
66 textureDescriptor.sampleCount = 1;
67 textureDescriptor.size = {kSize, kSize, 1};
68 return device.CreateTexture(&textureDescriptor);
69 }
70
DoTest(wgpu::FrontFace frontFace,wgpu::CullMode cullMode,bool isCCWTriangleCulled,bool isCWTriangleCulled)71 void DoTest(wgpu::FrontFace frontFace,
72 wgpu::CullMode cullMode,
73 bool isCCWTriangleCulled,
74 bool isCWTriangleCulled) {
75 wgpu::Texture colorTexture = Create2DTextureForTest(wgpu::TextureFormat::RGBA8Unorm);
76
77 utils::ComboRenderPassDescriptor renderPassDescriptor({colorTexture.CreateView()});
78 renderPassDescriptor.cColorAttachments[0].clearColor = {0.0, 0.0, 1.0, 1.0};
79 renderPassDescriptor.cColorAttachments[0].loadOp = wgpu::LoadOp::Clear;
80
81 wgpu::CommandEncoder commandEncoder = device.CreateCommandEncoder();
82 wgpu::RenderPassEncoder renderPass = commandEncoder.BeginRenderPass(&renderPassDescriptor);
83 renderPass.SetPipeline(CreatePipelineForTest(frontFace, cullMode));
84 renderPass.Draw(6);
85 renderPass.EndPass();
86 wgpu::CommandBuffer commandBuffer = commandEncoder.Finish();
87 queue.Submit(1, &commandBuffer);
88
89 const RGBA8 kBackgroundColor = RGBA8::kBlue;
90 const RGBA8 kTopLeftColor = RGBA8::kBlack;
91 constexpr RGBA8 kBottomRightColor = RGBA8(3, 3, 0, 255);
92
93 RGBA8 kCCWTriangleTopLeftColor = isCCWTriangleCulled ? kBackgroundColor : kTopLeftColor;
94 EXPECT_PIXEL_RGBA8_EQ(kCCWTriangleTopLeftColor, colorTexture, 0, 0);
95
96 RGBA8 kCWTriangleBottomRightColor =
97 isCWTriangleCulled ? kBackgroundColor : kBottomRightColor;
98 EXPECT_PIXEL_RGBA8_EQ(kCWTriangleBottomRightColor, colorTexture, kSize - 1, kSize - 1);
99 }
100
101 static constexpr uint32_t kSize = 4;
102 };
103
TEST_P(CullingTest,CullNoneWhenCCWIsFrontFace)104 TEST_P(CullingTest, CullNoneWhenCCWIsFrontFace) {
105 DoTest(wgpu::FrontFace::CCW, wgpu::CullMode::None, false, false);
106 }
107
TEST_P(CullingTest,CullFrontFaceWhenCCWIsFrontFace)108 TEST_P(CullingTest, CullFrontFaceWhenCCWIsFrontFace) {
109 DoTest(wgpu::FrontFace::CCW, wgpu::CullMode::Front, true, false);
110 }
111
TEST_P(CullingTest,CullBackFaceWhenCCWIsFrontFace)112 TEST_P(CullingTest, CullBackFaceWhenCCWIsFrontFace) {
113 DoTest(wgpu::FrontFace::CCW, wgpu::CullMode::Back, false, true);
114 }
115
TEST_P(CullingTest,CullNoneWhenCWIsFrontFace)116 TEST_P(CullingTest, CullNoneWhenCWIsFrontFace) {
117 DoTest(wgpu::FrontFace::CW, wgpu::CullMode::None, false, false);
118 }
119
TEST_P(CullingTest,CullFrontFaceWhenCWIsFrontFace)120 TEST_P(CullingTest, CullFrontFaceWhenCWIsFrontFace) {
121 DoTest(wgpu::FrontFace::CW, wgpu::CullMode::Front, false, true);
122 }
123
TEST_P(CullingTest,CullBackFaceWhenCWIsFrontFace)124 TEST_P(CullingTest, CullBackFaceWhenCWIsFrontFace) {
125 DoTest(wgpu::FrontFace::CW, wgpu::CullMode::Back, true, false);
126 }
127
128 DAWN_INSTANTIATE_TEST(CullingTest,
129 D3D12Backend(),
130 MetalBackend(),
131 OpenGLBackend(),
132 OpenGLESBackend(),
133 VulkanBackend());
134