src/dawn/samples/HelloTriangle.cpp

// Copyright 2017 The Dawn & Tint Authors
//
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// modification, are permitted provided that the following conditions are met:
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//    list of conditions and the following disclaimer.
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//    this list of conditions and the following disclaimer in the documentation
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// 3. Neither the name of the copyright holder nor the names of its
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//    this software without specific prior written permission.
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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#include <vector>

#include "dawn/samples/SampleUtils.h"

#include "dawn/utils/ComboRenderPipelineDescriptor.h"
#include "dawn/utils/WGPUHelpers.h"

class HelloTriangleSample : public SampleBase {
  public:
    using SampleBase::SampleBase;

  private:
    bool SetupImpl() override {
        static const float vertexData[12] = {
            0.0f, 0.5f, 0.0f, 1.0f, -0.5f, -0.5f, 0.0f, 1.0f, 0.5f, -0.5f, 0.0f, 1.0f,
        };
        vertexBuffer = dawn::utils::CreateBufferFromData(device, vertexData, sizeof(vertexData),
                                                         wgpu::BufferUsage::Vertex);

        wgpu::ShaderModule module = dawn::utils::CreateShaderModule(device, R"(
        @vertex fn vs(@location(0) pos : vec4f) -> @builtin(position) vec4f {
            return pos;
        }

        @fragment fn fs(@builtin(position) FragCoord : vec4f) -> @location(0) vec4f {
            return vec4f(1, 0, 0, 1);
        }
    )");

        dawn::utils::ComboRenderPipelineDescriptor descriptor;
        descriptor.layout = nullptr;
        descriptor.vertex.module = module;
        descriptor.vertex.bufferCount = 1;
        descriptor.cBuffers[0].arrayStride = 4 * sizeof(float);
        descriptor.cBuffers[0].attributeCount = 1;
        descriptor.cAttributes[0].format = wgpu::VertexFormat::Float32x4;
        descriptor.cFragment.module = module;
        descriptor.cTargets[0].format = GetPreferredSurfaceTextureFormat();

        pipeline = device.CreateRenderPipeline(&descriptor);
        return true;
    }

    void FrameImpl() override {
        wgpu::SurfaceTexture surfaceTexture;
        surface.GetCurrentTexture(&surfaceTexture);
        dawn::utils::ComboRenderPassDescriptor renderPass({surfaceTexture.texture.CreateView()});

        wgpu::CommandEncoder encoder = device.CreateCommandEncoder();
        {
            wgpu::RenderPassEncoder pass = encoder.BeginRenderPass(&renderPass);
            pass.SetPipeline(pipeline);
            pass.SetVertexBuffer(0, vertexBuffer);
            pass.Draw(3);
            pass.End();
        }

        wgpu::CommandBuffer commands = encoder.Finish();
        queue.Submit(1, &commands);
    }

    wgpu::Buffer vertexBuffer;
    wgpu::RenderPipeline pipeline;
};

int main(int argc, const char* argv[]) {
    if (!InitSample(argc, argv)) {
        return 1;
    }

    HelloTriangleSample* sample = new HelloTriangleSample();
    sample->Run(16000);
}