Add vertex buffer binding offset example

README.md

@@ -1,8 +1,9 @@
-Hello Triangle Vulkan demo
+Hello Triangle Vulkan demo -- vertex binding offset
 =========================
 
 This is a traditional Hello World style application for the Vulkan API. It
 renders a RGB shaded equilateral triangle (well, if the resolution is a square).
+And it tries if vertex binding offset using `vkCmdBindVertexBuffers()` works.
 
 The code is relatively flat and basic, so I think it's good enough for learning.
 No tutorial or even much comments are provided though (comments do lie anyway

src/HelloTriangle.cpp

@@ -45,7 +45,7 @@ using std::vector;
 // Config
 //////////////////////////////////////////////////////////////////////////////////
 
-const char appName[] = u8"Hello Vulkan Triangle";
+const char appName[] = u8"Hello Vulkan Triangle -- Vertex Offset";
 
 // layers and debug
 #if VULKAN_VALIDATION
@@ -225,7 +225,7 @@ void recordBeginRenderPass(
 void recordEndRenderPass( VkCommandBuffer commandBuffer );
 
 void recordBindPipeline( VkCommandBuffer commandBuffer, VkPipeline pipeline );
-void recordBindVertexBuffer( VkCommandBuffer commandBuffer, const uint32_t vertexBufferBinding, VkBuffer vertexBuffer );
+void recordBindVertexBuffer( VkCommandBuffer commandBuffer, const uint32_t vertexBufferBinding, VkBuffer vertexBuffer, VkDeviceSize offset );
 
 void recordDraw( VkCommandBuffer commandBuffer, uint32_t vertexCount );
 
@@ -244,6 +244,7 @@ int helloTriangle() try{
 
  const float triangleSize = 1.6f;
  const vector<Vertex2D_ColorF_pack> triangle = {
+ { /*unused*/{ { 0.0f, 0.0f} }, { {0.0f, 0.0f, 0.0f} } },
  { /*rb*/ { { 0.5f * triangleSize, sqrtf( 3.0f ) * 0.25f * triangleSize} }, /*R*/{ {1.0f, 0.0f, 0.0f} } },
  { /* t*/ { { 0.0f, -sqrtf( 3.0f ) * 0.25f * triangleSize} }, /*G*/{ {0.0f, 1.0f, 0.0f} } },
  { /*lb*/ { {-0.5f * triangleSize, sqrtf( 3.0f ) * 0.25f * triangleSize} }, /*B*/{ {0.0f, 0.0f, 1.0f} } }
@@ -464,9 +465,9 @@ int helloTriangle() try{
  recordBeginRenderPass( commandBuffers[i], renderPass, framebuffers[i], ::clearColor, surfaceSize.width, surfaceSize.height );
 
  recordBindPipeline( commandBuffers[i], pipeline );
- recordBindVertexBuffer( commandBuffers[i], vertexBufferBinding, vertexBuffer );
+ recordBindVertexBuffer(  commandBuffers[i], vertexBufferBinding, vertexBuffer, 1 * sizeof( Vertex2D_ColorF_pack )  );
 
- recordDraw( commandBuffers[i], static_cast<uint32_t>( triangle.size() ) );
+ recordDraw( commandBuffers[i], static_cast<uint32_t>( triangle.size() - 1 ) );
 
  recordEndRenderPass( commandBuffers[i] );
  endCommandBuffer( commandBuffers[i] );
@@ -1864,9 +1865,8 @@ void recordBindPipeline( VkCommandBuffer commandBuffer, VkPipeline pipeline ){
  vkCmdBindPipeline( commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline );
 }
 
-void recordBindVertexBuffer( VkCommandBuffer commandBuffer, const uint32_t vertexBufferBinding, VkBuffer vertexBuffer ){
- VkDeviceSize offsets[] = {0};
- vkCmdBindVertexBuffers( commandBuffer, vertexBufferBinding, 1 /*binding count*/, &vertexBuffer, offsets );
+void recordBindVertexBuffer( VkCommandBuffer commandBuffer, const uint32_t vertexBufferBinding, VkBuffer vertexBuffer, VkDeviceSize offset ){
+ vkCmdBindVertexBuffers( commandBuffer, vertexBufferBinding, 1 /*binding count*/, &vertexBuffer, &offset );
 }
 
 void recordDraw( VkCommandBuffer commandBuffer, const uint32_t vertexCount ){