Capture base address

Set in Push Constant
Use in Shader

Samples/5_Domain_Specific/simpleVulkanMMAP/MonteCarloPi.cu

@@ -290,7 +290,7 @@ void MonteCarloPiSimulation::setupSimulationAllocations() {
       cuMemSetAccess(d_ptr, m_totalAllocationSize, &accessDescriptor, 1));
 
   // fill the BDA buffer with something
-  const float bdaValues[2] = { 42.0f, 17.0f };
+  const float bdaValues[2] = { 0.2f, 0.2f };
   cuMemcpyHtoD(va_BDA, &bdaValues[0], sizeof(float) * 2);
 }
 

Samples/5_Domain_Specific/simpleVulkanMMAP/VulkanBaseApp.cpp

@@ -1083,8 +1083,14 @@ void VulkanBaseApp::createGraphicsPipeline() {
   pipelineLayoutInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
   pipelineLayoutInfo.setLayoutCount = 1;                    // Optional
   pipelineLayoutInfo.pSetLayouts = &m_descriptorSetLayout;  // Optional
-  pipelineLayoutInfo.pushConstantRangeCount = 0;            // Optional
-  pipelineLayoutInfo.pPushConstantRanges = nullptr;         // Optional
+
+  VkPushConstantRange pcr{};
+  pcr.stageFlags = VK_SHADER_STAGE_VERTEX_BIT;
+  pcr.offset = 0;
+  pcr.size = sizeof(uint64_t);
+
+  pipelineLayoutInfo.pushConstantRangeCount = 1;
+  pipelineLayoutInfo.pPushConstantRanges = &pcr;
 
   if (vkCreatePipelineLayout(m_device, &pipelineLayoutInfo, nullptr,
                              &m_pipelineLayout) != VK_SUCCESS) {

Samples/5_Domain_Specific/simpleVulkanMMAP/main.cpp

@@ -71,6 +71,7 @@ class VulkanCudaPi : public VulkanBaseApp {
   using chrono_tp = std::chrono::time_point<std::chrono::high_resolution_clock>;
   chrono_tp m_lastTime;
   size_t m_lastFrame;
+  uint64_t m_bdaBufferBaseAddress;
 
  public:
   VulkanCudaPi(size_t num_points)
@@ -88,7 +89,8 @@ class VulkanCudaPi : public VulkanBaseApp {
         m_vkSignalSemaphore(VK_NULL_HANDLE),
         m_cudaWaitSemaphore(),
         m_cudaSignalSemaphore(),
-        m_lastFrame(0) {
+        m_lastFrame(0),
+        m_bdaBufferBaseAddress(0) {
     // Add our compiled vulkan shader files
     char* vertex_shader_path =
         sdkFindFilePath("vert.spv", execution_path.c_str());
@@ -141,6 +143,12 @@ class VulkanCudaPi : public VulkanBaseApp {
     vkCmdBindVertexBuffers(commandBuffer, 0,
                            sizeof(vertexBuffers) / sizeof(vertexBuffers[0]),
                            vertexBuffers, offsets);
+    vkCmdPushConstants(commandBuffer,
+                       m_pipelineLayout,
+                       VK_SHADER_STAGE_VERTEX_BIT,
+                       0,
+                       sizeof(uint64_t),
+                       &m_bdaBufferBaseAddress);
     vkCmdDraw(commandBuffer, (uint32_t)(m_sim.getNumPoints()), 1, 0, 0);
   }
 
@@ -252,9 +260,9 @@ class VulkanCudaPi : public VulkanBaseApp {
     VkBufferDeviceAddressInfoKHR bda_info{VK_STRUCTURE_TYPE_BUFFER_DEVICE_ADDRESS_INFO_KHR,
                                           nullptr,
                                           m_bdaBuffer};
-    auto bda = vkGetBufferDeviceAddressKHR(m_device, &bda_info);
-    assert(bda);
-    std::cout << "DEBUG: BDA = " << (void*)bda << std::endl;
+    m_bdaBufferBaseAddress = vkGetBufferDeviceAddressKHR(m_device, &bda_info);
+    assert(m_bdaBufferBaseAddress);
+    std::cout << "DEBUG: BDA = " << (void*)m_bdaBufferBaseAddress << std::endl;
 
     // Create the semaphore vulkan will signal when it's done with the vertex
     // buffer

Samples/5_Domain_Specific/simpleVulkanMMAP/montecarlo.vert

@@ -56,22 +56,12 @@ layout(push_constant, std430) uniform Registers
   uint64_t base_address;
 } registers;
 
-layout(std430, binding = 0) buffer CUDA_SSBO {
-  float coords[2];
-} cuda_ssbo;
-
 void main() {
     gl_PointSize = 1.0;
     gl_Position = vec4(xyPos.xy, 0.0f, 1.0f);
 
-#if 0
-    gl_Position.x += cuda_ssbo.coords[0];
-    gl_Position.y += cuda_ssbo.coords[1];
-#endif
-#if 0
     gl_Position.x += BufferFloat(registers.base_address).f[0];
     gl_Position.y += BufferFloat(registers.base_address).f[1];
-#endif
 
     float color_r = 1.0f + 0.5f * sin(ubo.frame / 100.0f);
     float color_g = 1.0f + 0.5f * sin((ubo.frame / 100.0f) + (2.0f*PI/3.0f));