void reBuildCommandBuffers()
{
if (!checkCommandBuffers())
{
destroyCommandBuffers();
createCommandBuffers();
}
buildCommandBuffers();
}
void buildCommandBuffers()
{
// Destroy command buffers if already present
if (!checkCommandBuffers())
{
destroyCommandBuffers();
createCommandBuffers();
}
VkCommandBufferBeginInfo cmdBufInfo = vkTools::initializers::commandBufferBeginInfo();
VkClearValue clearValues[2];
clearValues[0].color = defaultClearColor;
clearValues[1].depthStencil = { 1.0f, 0 };
VkRenderPassBeginInfo renderPassBeginInfo = vkTools::initializers::renderPassBeginInfo();
renderPassBeginInfo.renderPass = renderPass;
renderPassBeginInfo.renderArea.offset.x = 0;
renderPassBeginInfo.renderArea.offset.y = 0;
renderPassBeginInfo.renderArea.extent.width = width;
renderPassBeginInfo.renderArea.extent.height = height;
renderPassBeginInfo.clearValueCount = 2;
renderPassBeginInfo.pClearValues = clearValues;
for (int32_t i = 0; i < drawCmdBuffers.size(); ++i)
{
// Set target frame buffer
renderPassBeginInfo.framebuffer = frameBuffers[i];
VK_CHECK_RESULT(vkBeginCommandBuffer(drawCmdBuffers[i], &cmdBufInfo));
// Compute particle movement
// Add memory barrier to ensure that the (rendering) vertex shader operations have finished
// Required as the compute shader will overwrite the vertex buffer data
VkBufferMemoryBarrier bufferBarrier = vkTools::initializers::bufferMemoryBarrier();
// Vertex shader invocations have finished reading from the buffer
bufferBarrier.srcAccessMask = VK_ACCESS_VERTEX_ATTRIBUTE_READ_BIT;
// Compute shader buffer read and write
bufferBarrier.dstAccessMask = VK_ACCESS_SHADER_WRITE_BIT | VK_ACCESS_SHADER_READ_BIT;
bufferBarrier.buffer = computeStorageBuffer.buffer;
bufferBarrier.size = computeStorageBuffer.descriptor.range;
bufferBarrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
bufferBarrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
vkCmdPipelineBarrier(
drawCmdBuffers[i],
VK_PIPELINE_STAGE_VERTEX_SHADER_BIT,
VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT,
VK_FLAGS_NONE,
0, nullptr,
1, &bufferBarrier,
0, nullptr);
vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_COMPUTE, pipelines.compute);
vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_COMPUTE, computePipelineLayout, 0, 1, &computeDescriptorSet, 0, 0);
// Dispatch the compute job
vkCmdDispatch(drawCmdBuffers[i], PARTICLE_COUNT / 16, 1, 1);
// Add memory barrier to ensure that compute shader has finished writing to the buffer
// Without this the (rendering) vertex shader may display incomplete results (partial data from last frame)
// Compute shader has finished writes to the buffer
bufferBarrier.srcAccessMask = VK_ACCESS_SHADER_WRITE_BIT;
// Vertex shader access (attribute binding)
bufferBarrier.dstAccessMask = VK_ACCESS_VERTEX_ATTRIBUTE_READ_BIT;
bufferBarrier.buffer = computeStorageBuffer.buffer;
bufferBarrier.size = computeStorageBuffer.descriptor.range;
bufferBarrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
bufferBarrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
vkCmdPipelineBarrier(
drawCmdBuffers[i],
VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT,
VK_PIPELINE_STAGE_VERTEX_SHADER_BIT,
VK_FLAGS_NONE,
0, nullptr,
1, &bufferBarrier,
0, nullptr);
// Draw the particle system using the update vertex buffer
vkCmdBeginRenderPass(drawCmdBuffers[i], &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);
VkViewport viewport = vkTools::initializers::viewport((float)width, (float)height, 0.0f, 1.0f);
vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);
VkRect2D scissor = vkTools::initializers::rect2D(width, height, 0, 0);
vkCmdSetScissor(drawCmdBuffers[i], 0, 1, &scissor);
vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.postCompute);
vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 0, 1, &descriptorSetPostCompute, 0, NULL);
VkDeviceSize offsets[1] = { 0 };
vkCmdBindVertexBuffers(drawCmdBuffers[i], VERTEX_BUFFER_BIND_ID, 1, &computeStorageBuffer.buffer, offsets);
vkCmdDraw(drawCmdBuffers[i], PARTICLE_COUNT, 1, 0, 0);
vkCmdEndRenderPass(drawCmdBuffers[i]);
VK_CHECK_RESULT(vkEndCommandBuffer(drawCmdBuffers[i]));
}
}
void buildCommandBuffers()
{
// Destroy command buffers if already present
if (!checkCommandBuffers())
{
destroyCommandBuffers();
createCommandBuffers();
}
VkCommandBufferBeginInfo cmdBufInfo = vkTools::initializers::commandBufferBeginInfo();
VkClearValue clearValues[2];
clearValues[0].color = defaultClearColor;
clearValues[1].depthStencil = { 1.0f, 0 };
VkRenderPassBeginInfo renderPassBeginInfo = vkTools::initializers::renderPassBeginInfo();
renderPassBeginInfo.renderPass = renderPass;
renderPassBeginInfo.renderArea.offset.x = 0;
renderPassBeginInfo.renderArea.offset.y = 0;
renderPassBeginInfo.renderArea.extent.width = width;
renderPassBeginInfo.renderArea.extent.height = height;
renderPassBeginInfo.clearValueCount = 2;
renderPassBeginInfo.pClearValues = clearValues;
VkResult err;
for (int32_t i = 0; i < drawCmdBuffers.size(); ++i)
{
// Set target frame buffer
renderPassBeginInfo.framebuffer = frameBuffers[i];
err = vkBeginCommandBuffer(drawCmdBuffers[i], &cmdBufInfo);
assert(!err);
// Buffer memory barrier to make sure that compute shader
// writes are finished before using the storage buffer
// in the vertex shader
VkBufferMemoryBarrier bufferBarrier = vkTools::initializers::bufferMemoryBarrier();
// Source access : Compute shader buffer write
bufferBarrier.srcAccessMask = VK_ACCESS_SHADER_WRITE_BIT;
// Dest access : Vertex shader access (attribute binding)
bufferBarrier.dstAccessMask = VK_ACCESS_VERTEX_ATTRIBUTE_READ_BIT;
bufferBarrier.buffer = computeStorageBuffer.buffer;
bufferBarrier.offset = 0;
bufferBarrier.size = computeStorageBuffer.descriptor.range;
bufferBarrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
bufferBarrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
vkCmdPipelineBarrier(
drawCmdBuffers[i],
VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT,
VK_FLAGS_NONE,
0, nullptr,
1, &bufferBarrier,
0, nullptr);
vkCmdBeginRenderPass(drawCmdBuffers[i], &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);
VkViewport viewport = vkTools::initializers::viewport(
(float)width,
(float)height,
0.0f,
1.0f
);
vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);
VkRect2D scissor = vkTools::initializers::rect2D(
width,
height,
0,
0
);
vkCmdSetScissor(drawCmdBuffers[i], 0, 1, &scissor);
vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 0, 1, &descriptorSetPostCompute, 0, NULL);
vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.postCompute);
VkDeviceSize offsets[1] = { 0 };
vkCmdBindVertexBuffers(drawCmdBuffers[i], VERTEX_BUFFER_BIND_ID, 1, &computeStorageBuffer.buffer, offsets);
vkCmdDraw(drawCmdBuffers[i], PARTICLE_COUNT, 1, 0, 0);
vkCmdEndRenderPass(drawCmdBuffers[i]);
err = vkEndCommandBuffer(drawCmdBuffers[i]);
assert(!err);
}
}
