InputLayoutDescriptor 제작

OpenGL 만 다르다;

그렇다고 DirectX 랑 Vulkan, Metal 이 다 똑같지는 않다.

    std::vector<InputDesc> VertElem
    {
        { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, D3D11_APPEND_ALIGNED_ELEMENT, D3D11_INPUT_PER_VERTEX_DATA, 0 },
        { "NORMAL", 0, DXGI_FORMAT_R32G32B32_FLOAT, 1, D3D11_APPEND_ALIGNED_ELEMENT, D3D11_INPUT_PER_VERTEX_DATA, 0 },
        { "TEXTURE", 0, DXGI_FORMAT_R32G32_FLOAT, 2, D3D11_APPEND_ALIGNED_ELEMENT, D3D11_INPUT_PER_VERTEX_DATA, 0 },
        { "EDGE_SCALE", 0, DXGI_FORMAT_R32_FLOAT, 3, D3D11_APPEND_ALIGNED_ELEMENT, D3D11_INPUT_PER_VERTEX_DATA, 0 },
    };

    m_CommandList->IASetVertexBuffers( Slot, 1, &Buffer.Buffer, &Buffer.StrideInBytes, &Buffer.Offset );

불칸은

    static VkVertexInputBindingDescription getBindingDescription() {
        VkVertexInputBindingDescription bindingDescription = {};
        bindingDescription.binding = 0;
        bindingDescription.stride = sizeof(Vertex);
        bindingDescription.inputRate = VK_VERTEX_INPUT_RATE_VERTEX;

        return bindingDescription;
    }

    static std::array<VkVertexInputAttributeDescription, 2> getAttributeDescription() {
        std::array<VkVertexInputAttributeDescription, 2> attributeDescriptions = {};

        attributeDescriptions[0].binding = 0;
        attributeDescriptions[0].location = 0;
        attributeDescriptions[0].format = VK_FORMAT_R32G32_SFLOAT;
        attributeDescriptions[0].offset = offsetof(Vertex, pos);

        attributeDescriptions[1].binding = 0;
        attributeDescriptions[1].location = 1;
        attributeDescriptions[1].format = VK_FORMAT_R32G32B32_SFLOAT;
        attributeDescriptions[1].offset = offsetof(Vertex, color);

        return attributeDescriptions;
    }
};

void vkCmdBindVertexBuffers(
    VkCommandBuffer                             commandBuffer,
    uint32_t                                    firstBinding,
    uint32_t                                    bindingCount,
    const VkBuffer*                             pBuffers,
    const VkDeviceSize*                         pOffsets);

2개로 나눠져 있다;

메탈은,

    Check out MTLVertexBufferLayoutDescriptor, which is part of MTLRenderPipelineDescriptor.It has the stride member.

    Below is the example of settings up three vertex attributes stored in one vertex buffer in the interleaved fashion.The stride is set next to the end : vertexDescriptor.layouts[0].stride = 32;

    MTLRenderPipelineDescriptor *pipelineDescriptor = [[MTLRenderPipelineDescriptor alloc] init];

    MTLVertexDescriptor *vertexDescriptor = [MTLVertexDescriptor vertexDescriptor];
    vertexDescriptor.attributes[0].offset = 0;
    vertexDescriptor.attributes[0].format = MTLVertexFormatFloat3; // position
    vertexDescriptor.attributes[0].bufferIndex = 0;
    vertexDescriptor.attributes[1].offset = 12;
    vertexDescriptor.attributes[1].format = MTLVertexFormatFloat3; // normal
    vertexDescriptor.attributes[1].bufferIndex = 0;
    vertexDescriptor.attributes[2].offset = 24;
    vertexDescriptor.attributes[2].format = MTLVertexFormatFloat2; // texCoords
    vertexDescriptor.attributes[2].bufferIndex = 0;

    vertexDescriptor.layouts[0].stepRate = 1;
    vertexDescriptor.layouts[0].stepFunction = MTLVertexStepFunctionPerVertex;
    vertexDescriptor.layouts[0].stride = 32;

location만 빠진 형태

openGL은

    glBindVertexBuffer(it.slot, vbos[it.slot].vbo->getInstanceID(), vbos[it.slot].offset, _bindings[it.slot].stride);

or

    GL_CHECK(glEnableVertexAttribArray(attrib.location));
    GL_CHECK(glVertexAttribPointer(attrib.location, attrib.size, attrib.type, GL_FALSE, stride, offset));

매 render 마다 하는 식;

결국, reflection 사용해서 아래와 같은 식으로 전개