// Unified Interface:
CommandBuffer::DrawIndexed(std::uint32_t numIndices, std::uint32_t firstIndex);

// OpenGL Implementation:
void GLCommandBuffer::DrawIndexed(std::uint32_t numIndices, std::uint32_t firstIndex) {
    const GLintptr indices = (renderState_.indexBufferOffset + firstIndex * renderState_.indexBufferStride);
    glDrawElements(
        renderState_.drawMode,
        static_cast<GLsizei>(numIndices),
        renderState_.indexBufferDataType,
        reinterpret_cast<const GLvoid*>(indices)
    );
}

// Direct3D 11 Implementation
void D3D11CommandBuffer::DrawIndexed(std::uint32_t numIndices, std::uint32_t firstIndex) {
    context_->DrawIndexed(numIndices, firstIndex, 0);
}

// Direct3D 12 Implementation
void D3D12CommandBuffer::DrawIndexed(std::uint32_t numIndices, std::uint32_t firstIndex) {
    commandList_->DrawIndexedInstanced(numIndices, 1, firstIndex, 0, 0);
}

// Vulkan Implementation
void VKCommandBuffer::DrawIndexed(std::uint32_t numIndices, std::uint32_t firstIndex) {
    vkCmdDrawIndexed(commandBuffer_, numIndices, 1, firstIndex, 0, 0);
}

// Metal implementation
void MTCommandBuffer::DrawIndexed(std::uint32_t numIndices, std::uint32_t firstIndex) {
    if (numPatchControlPoints_ > 0) {
        [renderEncoder_
            drawIndexedPatches:             numPatchControlPoints_
            patchStart:                     static_cast<NSUInteger>(firstIndex) / numPatchControlPoints_
            patchCount:                     static_cast<NSUInteger>(numIndices) / numPatchControlPoints_
            patchIndexBuffer:               nil
            patchIndexBufferOffset:         0
            controlPointIndexBuffer:        indexBuffer_
            controlPointIndexBufferOffset:  indexTypeSize_ * (static_cast<NSUInteger>(firstIndex))
            instanceCount:                  1
            baseInstance:                   0
        ];
    } else {
        [renderEncoder_
            drawIndexedPrimitives:  primitiveType_
            indexCount:             static_cast<NSUInteger>(numIndices)
            indexType:              indexType_
            indexBuffer:            indexBuffer_
            indexBufferOffset:      indexTypeSize_ * static_cast<NSUInteger>(firstIndex)
        ];
    }
}