//--- usage ------------------------------------------------//

void usage() {
    VertexBindings(vbindings) = {
        { .binding = 0, .stride = 12, PerVertex },
        { .binding = 1, .stride = 12, PerVertex },
        { .binding = 2, .stride = 8 , PerVertex },
        { .binding = 3, .stride = 16, PerInstance },
    };

    VertexAttrs(vattrs) = {
        // loc , binding , format          , offset ,
        { 0    , 0       , VertexFormat_F3 , 0      , },
        { 1    , 1       , VertexFormat_F3 , 0      , },
        { 2    , 2       , VertexFormat_F2 , 0      , },
        { 3    , 3       , VertexFormat_F4 , 0      , },
    };

    BlendAttachments(attachments) = {
        BlendAttachment(
            SrcColorBlend(ONE),
            DstColorBlend(ONE),
            ColorBlendOp(ADD),
            AlphaBlendOp(ADD),
        ),

        BlendAttachment(
            SrcColorBlend(ONE),
            DstColorBlend(ONE),
            ColorBlendOp(ADD),
            AlphaBlendOp(ADD),
        ),

        { }, // disabled

        BlendAttachment(
            SrcColorBlend(ONE),
            DstColorBlend(ONE),
            ColorBlendOp(ADD),
            AlphaBlendOp(ADD),
        ),
    };

    VkGraphicsPipelineCreateInfo defaults[1] = {
        GfxPipeline(
            VertexInput(vbindings, vattrs),
            Rasterization(
                CullBack,   // CullFront, CullNone
                PolyFill,    // PolyLine, PolyPoint
                FrontCCW,    // FrontCW
            ),
            Viewport(),
            InputAssembly(TriangleList), // PointList, LineList, TriangleStrip, TriangleFan
            DepthStencil(
                DepthTest = true, 
                DepthWrite = true, 
                DepthCompare(LESS_OR_EQUAL),
                DepthBoundsEnable(0.0, 1.0),
            ),
            Blend(attachments, .blendConstants = {0,1,0,1}),
            // .layout = 
            // .renderPass = 
            // .subpass = 
        ),
    };
}

//--- dynamic state ------------------------------------------------//

#define DynamicStateDefaults() \
    .pDynamicState = &(VkPipelineDynamicStateCreateInfo) { \
        .sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO, \
        .dynamicStateCount = 2,  \
        .pDynamicStates = (VkDynamicState[]) { \
            VK_DYNAMIC_STATE_VIEWPORT, \
            VK_DYNAMIC_STATE_SCISSOR, \
        },\
    }

//--- depth-stencil ------------------------------------------------//

#define DepthTest           .depthTestEnable 
#define DepthWrite          .depthWriteEnable 
#define DepthCompare(op)    .depthCompareOp = VK_COMPARE_OP_##op

#define DepthBoundsEnable(minn, maxx) \
    .depthBoundsTestEnable = true, \
    .minDepthBounds = minn, \
    .maxDepthBounds = maxx,


#define DepthStencil(...) \
    .pDepthStencilState = &(VkPipelineDepthStencilStateCreateInfo) { \
        .sType = VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO, \
        DepthTest   = true, \
        DepthWrite  = true, \
        DepthCompare(LESS_OR_EQUAL), \
    } \


//--- blend ------------------------------------------------//

#define BlendFactor(fac) VK_BLEND_FACTOR_##fac
#define SrcColorBlend(fac) .srcColorBlendFactor = BlendFactor(fac)
#define DstColorBlend(fac) .dstColorBlendFactor = BlendFactor(fac)
#define SrcAlphaBlend(fac) .srcAlphaBlendFactor = BlendFactor(fac)
#define DstAlphaBlend(fac) .dstAlphaBlendFactor = BlendFactor(fac)
#define ColorBlendOp(op) .colorBlendOp = VK_BLEND_OP_##op
#define AlphaBlendOp(op) .alphaBlendOp = VK_BLEND_OP_##op

#define BlendAttachments(var) VkPipelineColorBlendAttachmentState var[]
#define BlendAttachment(...) \
    (VkPipelineColorBlendAttachmentState) { \
        .blendEnable = true, \
        .colorWriteMask = VK_COLOR_COMPONENT_R_BIT  \
        | VK_COLOR_COMPONENT_G_BIT \
        | VK_COLOR_COMPONENT_B_BIT \
        | VK_COLOR_COMPONENT_A_BIT, \
        __VA_ARGS__ \
    }

#define Blend(attach, ...) \
    .pColorBlendState = &(VkPipelineColorBlendStateCreateInfo) { \
        .sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO, \
        .attachmentCount = ARRAYCOUNT(attach), \
        .pAttachments = attach, \
        __VA_ARGS__ \
    }

//--- input assembly ------------------------------------------------//

#define PointList       .topology = VK_PRIMITIVE_TOPOLOGY_POINT_LIST
#define LineList        .topology = VK_PRIMITIVE_TOPOLOGY_LINE_LIST
#define TriangleList    .topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST
#define TriangleStrip   .topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP
#define TriangleFan     .topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN

#define InputAssembly(...) \
    .pInputAssemblyState = &(VkPipelineInputAssemblyStateCreateInfo) { \
        .sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO, \
        TriangleList, \
        __VA_ARGS__ \
    }

//--- viewport ------------------------------------------------//

#define Viewport(...)  \
    .pViewportState = &(VkPipelineViewportStateCreateInfo) { \
        .sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO, \
        .viewportCount = 1, \
    }

//--- rasterizer ------------------------------------------------//

#define PolyFill    .polygonMode = VK_POLYGON_MODE_FILL
#define PolyLine    .polygonMode = VK_POLYGON_MODE_LINE
#define PolyPoint   .polygonMode = VK_POLYGON_MODE_POINT

#define FrontCW     .frontFace = VK_FRONT_FACE_CLOCKWISE
#define FrontCCW    .frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE

#define CullFront   .cullMode = VK_CULL_MODE_FRONT_BIT
#define CullBack    .cullMode = VK_CULL_MODE_BACK_BIT
#define CullNone    .cullMode = VK_CULL_MODE_NONE

#define Rasterization(...) \
    .pRasterizationState = &(VkPipelineRasterizationStateCreateInfo) { \
        .sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO, \
        CullBack , PolyFill , FrontCCW,  \
        __VA_ARGS__ \
    }

//--- vertex input ------------------------------------------------//

#define VertexBindings(var) VkVertexInputBindingDescription var[]
#define VertexAttrs(var)    VkVertexInputAttributeDescription var[]
#define PerVertex   .inputRate = VK_VERTEX_INPUT_RATE_VERTEX
#define PerInstance .inputRate = VK_VERTEX_INPUT_RATE_INSTANCE

#define VertexFormat_U4 VK_FORMAT_R32_UINT
#define VertexFormat_F1 VK_FORMAT_R32_SFLOAT
#define VertexFormat_F2 VK_FORMAT_R32G32_SFLOAT
#define VertexFormat_F3 VK_FORMAT_R32G32B32_SFLOAT
#define VertexFormat_F4 VK_FORMAT_R32G32B32A32_SFLOAT

#define VertexInput(bindings, attrs) \
    .pVertexInputState = &(VkPipelineVertexInputStateCreateInfo) { \
        .sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO, \
        .pVertexBindingDescriptions = bindings, \
        .vertexBindingDescriptionCount = ARRAYCOUNT(bindings), \
        .pVertexAttributeDescriptions = attrs, \
        .vertexAttributeDescriptionCount = ARRAYCOUNT(attrs), \
    }

//--- pipeline ------------------------------------------------//

#define GfxPipeline(...) (VkGraphicsPipelineCreateInfo) { \
    .sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO, \
    Rasterization(), \
    Viewport(), \
    InputAssembly(), \
    DepthStencil(), \
    DynamicStateDefaults(), \
    __VA_ARGS__ \
}