14_command_buffers.diff

diff --git a/../steps/13_framebuffers/main.go b/../steps/14_command_buffers/main.go
index 34d50ec..c6fa94d 100644
--- a/../steps/13_framebuffers/main.go
+++ b/../steps/14_command_buffers/main.go
@@ -64,6 +64,9 @@ type HelloTriangleApplication struct {
 	renderPass       core1_0.RenderPass
 	pipelineLayout   core1_0.PipelineLayout
 	graphicsPipeline core1_0.Pipeline
+
+	commandPool    core1_0.CommandPool
+	commandBuffers []core1_0.CommandBuffer
 }
 
 func (app *HelloTriangleApplication) Run() error {
@@ -141,7 +144,17 @@ func (app *HelloTriangleApplication) initVulkan() error {
 		return err
 	}
 
-	return app.createFramebuffers()
+	err = app.createFramebuffers()
+	if err != nil {
+		return err
+	}
+
+	err = app.createCommandPool()
+	if err != nil {
+		return err
+	}
+
+	return app.createCommandBuffers()
 }
 
 func (app *HelloTriangleApplication) mainLoop() error {
@@ -159,6 +172,10 @@ appLoop:
 }
 
 func (app *HelloTriangleApplication) cleanup() {
+	if app.commandPool != nil {
+		app.commandPool.Destroy(nil)
+	}
+
 	for _, framebuffer := range app.swapchainFramebuffers {
 		framebuffer.Destroy(nil)
 	}
@@ -673,6 +690,71 @@ func (app *HelloTriangleApplication) createFramebuffers() error {
 	return nil
 }
 
+func (app *HelloTriangleApplication) createCommandPool() error {
+	indices, err := app.findQueueFamilies(app.physicalDevice)
+	if err != nil {
+		return err
+	}
+
+	pool, _, err := app.device.CreateCommandPool(nil, core1_0.CommandPoolCreateInfo{
+		QueueFamilyIndex: *indices.GraphicsFamily,
+	})
+
+	if err != nil {
+		return err
+	}
+	app.commandPool = pool
+
+	return nil
+}
+
+func (app *HelloTriangleApplication) createCommandBuffers() error {
+
+	buffers, _, err := app.device.AllocateCommandBuffers(core1_0.CommandBufferAllocateInfo{
+		CommandPool:        app.commandPool,
+		Level:              core1_0.CommandBufferLevelPrimary,
+		CommandBufferCount: len(app.swapchainImages),
+	})
+	if err != nil {
+		return err
+	}
+	app.commandBuffers = buffers
+
+	for bufferIdx, buffer := range buffers {
+		_, err = buffer.Begin(core1_0.CommandBufferBeginInfo{})
+		if err != nil {
+			return err
+		}
+
+		err = buffer.CmdBeginRenderPass(core1_0.SubpassContentsInline,
+			core1_0.RenderPassBeginInfo{
+				RenderPass:  app.renderPass,
+				Framebuffer: app.swapchainFramebuffers[bufferIdx],
+				RenderArea: core1_0.Rect2D{
+					Offset: core1_0.Offset2D{X: 0, Y: 0},
+					Extent: app.swapchainExtent,
+				},
+				ClearValues: []core1_0.ClearValue{
+					core1_0.ClearValueFloat{0, 0, 0, 1},
+				},
+			})
+		if err != nil {
+			return err
+		}
+
+		buffer.CmdBindPipeline(core1_0.PipelineBindPointGraphics, app.graphicsPipeline)
+		buffer.CmdDraw(3, 1, 0, 0)
+		buffer.CmdEndRenderPass()
+
+		_, err = buffer.End()
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func (app *HelloTriangleApplication) chooseSwapSurfaceFormat(availableFormats []khr_surface.SurfaceFormat) khr_surface.SurfaceFormat {
 	for _, format := range availableFormats {
 		if format.Format == core1_0.FormatB8G8R8A8SRGB && format.ColorSpace == khr_surface.ColorSpaceSRGBNonlinear {