Merge pull request #35 from FunMiles/shader_specialization

Shader specialization

Author: lhog

examples/teapot/teapot.cpp

@@ -141,7 +141,7 @@ int main() {
 		{
 
 			vku::PipelineMaker pm{window.width(), window.height()};
-			pm.shader(vk::ShaderStageFlagBits::eVertex, final_vert);
+			pm.shader(vk::ShaderStageFlagBits::eVertex, final_vert, {{0,3}});
 			pm.shader(vk::ShaderStageFlagBits::eFragment, final_frag);
 			pm.vertexBinding(0, (uint32_t)sizeof(Vertex));
 			pm.vertexAttribute(0, 0, vk::Format::eR32G32B32Sfloat, (uint32_t)offsetof(Vertex, pos));

examples/teapot/teapot.vert

@@ -1,5 +1,5 @@
 #version 450
-
+layout (constant_id = 0) const int xF = 1;
 layout(location = 0) in vec3 inPosition;
 layout(location = 1) in vec3 inNormal;
 layout(location = 2) in vec2 inUv;
@@ -26,6 +26,7 @@ out gl_PerVertex {
 void main() {
   // Get position in camera, light and world space.
   gl_Position = u.modelToPerspective * vec4(inPosition.xyz, 1.0);
+  gl_Position.x *= xF;
   vec4 lightSpacePos = u.modelToLight * vec4(inPosition.xyz, 1.0);
   vec3 worldPos = (u.modelToWorld * vec4(inPosition.xyz, 1.0)).xyz;
 

include/vku/vku.hpp

@@ -860,6 +860,37 @@ class PipelineMaker {
     modules_.emplace_back(info);
   }
 
+  struct SpecEntry {
+    uint32_t    constantID;
+    uint32_t    value;
+  };
+  /// Add a shader module with specialized constants to the pipeline.
+  void shader(vk::ShaderStageFlagBits stage, vku::ShaderModule &shader,
+              std::initializer_list<SpecEntry> specEntries,
+              const char *entryPoint = "main") {
+    auto data = std::unique_ptr<SpecData>{new SpecData};
+    uint32_t offset = 0;
+    data->data_size_ = specEntries.size()*sizeof(uint32_t);
+    data->data_ = std::unique_ptr<char[]>(new char[data->data_size_]);
+    for (auto &entry : specEntries) {
+      data->specializationMapEntries_.emplace_back(
+          entry.constantID, offset, sizeof(uint32_t));
+      *reinterpret_cast<int32_t *>(data->data_.get() + offset) = entry.value;
+      offset += sizeof(uint32_t);
+    }
+    data->specializationInfo_.mapEntryCount = specEntries.size();
+    data->specializationInfo_.pMapEntries = data->specializationMapEntries_.data();
+    data->specializationInfo_.dataSize = data->data_size_;
+    data->specializationInfo_.pData = data->data_.get();
+    vk::PipelineShaderStageCreateInfo info{};
+    info.module = shader.module();
+    info.pName = entryPoint;
+    info.stage = stage;
+    info.pSpecializationInfo = &data->specializationInfo_;
+    modules_.emplace_back(info);
+    moduleSpecializations_.emplace_back(std::move(data));
+  }
+
   /// Add a blend state to the pipeline for one colour attachment.
   /// If you don't do this, a default is used.
   void colorBlend(const vk::PipelineColorBlendAttachmentState &state) {
@@ -1012,6 +1043,13 @@ class PipelineMaker {
   vk::PipelineColorBlendStateCreateInfo colorBlendState_;
   std::vector<vk::PipelineColorBlendAttachmentState> colorBlendAttachments_;
   std::vector<vk::PipelineShaderStageCreateInfo> modules_;
+  struct SpecData {
+    vk::SpecializationInfo specializationInfo_;
+    std::vector<vk::SpecializationMapEntry> specializationMapEntries_;
+    std::unique_ptr<char []> data_;
+    size_t data_size_;
+  };
+  std::vector<std::unique_ptr<SpecData>> moduleSpecializations_;
   std::vector<vk::VertexInputAttributeDescription> vertexAttributeDescriptions_;
   std::vector<vk::VertexInputBindingDescription> vertexBindingDescriptions_;
   std::vector<vk::DynamicState> dynamicState_;

include/vku/vku_framework.hpp

@@ -407,9 +407,8 @@ class Window {
     device.waitForFences(cbFence, 1, umax);
     device.resetFences(cbFence);
 
-    std::array<float, 4> clearColorValue{0.75f, 0.75f, 0.75f, 1};
     vk::ClearDepthStencilValue clearDepthValue{ 1.0f, 0 };
-    std::array<vk::ClearValue, 2> clearColours{vk::ClearValue{clearColorValue}, clearDepthValue};
+    std::array<vk::ClearValue, 2> clearColours{vk::ClearValue{clearColorValue()}, clearDepthValue};
     vk::RenderPassBeginInfo rpbi;
     rpbi.renderPass = *renderPass_;
     rpbi.framebuffer = *framebuffers_[imageIndex];
@@ -643,6 +642,8 @@ class Window {
 
   vk::Device device() const { return device_; }
 
+  std::array<float,4> &clearColorValue() { return clearColorValue_; }
+
 private:
   vk::Instance instance_;
   vk::PhysicalDevice physicalDevice_;
@@ -670,6 +671,7 @@ class Window {
   uint32_t presentQueueFamily_ = 0;
   uint32_t width_;
   uint32_t height_;
+  std::array<float, 4> clearColorValue_{0.75f, 0.75f, 0.75f, 1};
   vk::Format swapchainImageFormat_ = vk::Format::eB8G8R8A8Unorm;
   vk::ColorSpaceKHR swapchainColorSpace_ = vk::ColorSpaceKHR::eSrgbNonlinear;
   vk::Device device_;