[Vulkan] Uniform Buffer보다 빠르고 간단한 PushConstant을 사용하고 싶어요.

PushConstant

auto props = physicalDevice.getProperties();
std::cout << "maxPushConstantsSize: " << props.limits.maxPushConstantsSize;
// maxPushConstantsSize: 256

설정

농담

layout(push_constant) uniform PushConstants {
    vec2 mousePosition;
    vec2 mouseMove;
} pushConstant;

C++ 측면에서 구조체 구성하기

struct PushConstants
{
    float mousePosition[2];
    float mouseMove[2];
};

PushConstants pushConstants;

Piperline Layout을 제작할 때 PushContantrange에 맡기기

vk::PushConstantRange pushRange;
pushRange.setOffset(0);
pushRange.setSize(sizeof(PushConstants));
pushRange.setStageFlags(vk::ShaderStageFlagBits::eCompute);

vk::PipelineLayoutCreateInfo createInfo;
createInfo.setSetLayouts(*descSetLayout);
createInfo.setPushConstantRanges(pushRange);
vk::PipelineLayout pipelineLayout = device.createPipelineLayout(createInfo);

명령 버퍼 요청

commandBuffer.pushConstants(
  *pipelineLayout, 
  vk::ShaderStageFlagBits::eCompute, 
  0, sizeof(PushConstants), &pushConstants);