diff --git a/examples/vulkan_example/main.cpp b/examples/vulkan_example/main.cpp index 957afc43f..f3a86e0ed 100644 --- a/examples/vulkan_example/main.cpp +++ b/examples/vulkan_example/main.cpp @@ -13,7 +13,9 @@ #define IMGUI_MAX_POSSIBLE_BACK_BUFFERS 16 #define IMGUI_UNLIMITED_FRAME_RATE +//#ifdef _DEBUG //#define IMGUI_VULKAN_DEBUG_REPORT +//#endif static VkAllocationCallbacks* g_Allocator = NULL; static VkInstance g_Instance = VK_NULL_HANDLE; @@ -34,7 +36,7 @@ static VkPipelineCache g_PipelineCache = VK_NULL_HANDLE; static VkDescriptorPool g_DescriptorPool = VK_NULL_HANDLE; static int fb_width, fb_height; -static uint32_t g_BackBufferIndex = 0; +static uint32_t g_BackbufferIndices[IMGUI_VK_QUEUED_FRAMES]; // keep track of recently rendered swapchain frame indices static uint32_t g_BackBufferCount = 0; static VkImage g_BackBuffer[IMGUI_MAX_POSSIBLE_BACK_BUFFERS] = {}; static VkImageView g_BackBufferView[IMGUI_MAX_POSSIBLE_BACK_BUFFERS] = {}; @@ -44,7 +46,8 @@ static uint32_t g_FrameIndex = 0; static VkCommandPool g_CommandPool[IMGUI_VK_QUEUED_FRAMES]; static VkCommandBuffer g_CommandBuffer[IMGUI_VK_QUEUED_FRAMES]; static VkFence g_Fence[IMGUI_VK_QUEUED_FRAMES]; -static VkSemaphore g_Semaphore[IMGUI_VK_QUEUED_FRAMES]; +static VkSemaphore g_PresentCompleteSemaphore[IMGUI_VK_QUEUED_FRAMES]; +static VkSemaphore g_RenderCompleteSemaphore[IMGUI_VK_QUEUED_FRAMES]; static VkClearValue g_ClearValue = {}; @@ -452,7 +455,9 @@ static void setup_vulkan(GLFWwindow* window) { VkSemaphoreCreateInfo info = {}; info.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO; - err = vkCreateSemaphore(g_Device, &info, g_Allocator, &g_Semaphore[i]); + err = vkCreateSemaphore(g_Device, &info, g_Allocator, &g_PresentCompleteSemaphore[i]); + check_vk_result(err); + err = vkCreateSemaphore(g_Device, &info, g_Allocator, &g_RenderCompleteSemaphore[i]); check_vk_result(err); } } @@ -492,7 +497,8 @@ static void cleanup_vulkan() vkDestroyFence(g_Device, g_Fence[i], g_Allocator); vkFreeCommandBuffers(g_Device, g_CommandPool[i], 1, &g_CommandBuffer[i]); vkDestroyCommandPool(g_Device, g_CommandPool[i], g_Allocator); - vkDestroySemaphore(g_Device, g_Semaphore[i], g_Allocator); + vkDestroySemaphore(g_Device, g_PresentCompleteSemaphore[i], g_Allocator); + vkDestroySemaphore(g_Device, g_RenderCompleteSemaphore[i], g_Allocator); } for (uint32_t i = 0; i < g_BackBufferCount; i++) { @@ -525,7 +531,7 @@ static void frame_begin() check_vk_result(err); } { - err = vkAcquireNextImageKHR(g_Device, g_Swapchain, UINT64_MAX, g_Semaphore[g_FrameIndex], VK_NULL_HANDLE, &g_BackBufferIndex); + err = vkAcquireNextImageKHR(g_Device, g_Swapchain, UINT64_MAX, g_PresentCompleteSemaphore[g_FrameIndex], VK_NULL_HANDLE, &g_BackbufferIndices[g_FrameIndex]); check_vk_result(err); } { @@ -541,7 +547,7 @@ static void frame_begin() VkRenderPassBeginInfo info = {}; info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO; info.renderPass = g_RenderPass; - info.framebuffer = g_Framebuffer[g_BackBufferIndex]; + info.framebuffer = g_Framebuffer[g_BackbufferIndices[g_FrameIndex]]; info.renderArea.extent.width = fb_width; info.renderArea.extent.height = fb_height; info.clearValueCount = 1; @@ -559,10 +565,12 @@ static void frame_end() VkSubmitInfo info = {}; info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO; info.waitSemaphoreCount = 1; - info.pWaitSemaphores = &g_Semaphore[g_FrameIndex]; + info.pWaitSemaphores = &g_PresentCompleteSemaphore[g_FrameIndex]; info.pWaitDstStageMask = &wait_stage; info.commandBufferCount = 1; info.pCommandBuffers = &g_CommandBuffer[g_FrameIndex]; + info.signalSemaphoreCount = 1; + info.pSignalSemaphores = &g_RenderCompleteSemaphore[g_FrameIndex]; err = vkEndCommandBuffer(g_CommandBuffer[g_FrameIndex]); check_vk_result(err); @@ -571,18 +579,32 @@ static void frame_end() err = vkQueueSubmit(g_Queue, 1, &info, g_Fence[g_FrameIndex]); check_vk_result(err); } - { - VkSwapchainKHR swapchains[1] = {g_Swapchain}; - uint32_t indices[1] = {g_BackBufferIndex}; - VkPresentInfoKHR info = {}; - info.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR; - info.swapchainCount = 1; - info.pSwapchains = swapchains; - info.pImageIndices = indices; - err = vkQueuePresentKHR(g_Queue, &info); - check_vk_result(err); - } - g_FrameIndex = (g_FrameIndex+1) % IMGUI_VK_QUEUED_FRAMES; +} + +static void frame_present() +{ + VkResult err; +// If IMGUI_UNLIMITED_FRAME_RATE is defined we present the latest but one frame +// Othrewise we present the latest rendered frame +#ifdef IMGUI_UNLIMITED_FRAME_RATE + uint32_t PresentIndex = (g_FrameIndex + IMGUI_VK_QUEUED_FRAMES - 1) % IMGUI_VK_QUEUED_FRAMES; +#else + uint32_t PresentIndex = g_FrameIndex; +#endif // IMGUI_UNLIMITED_FRAME_RATE + + VkSwapchainKHR swapchains[1] = {g_Swapchain}; + uint32_t indices[1] = {g_BackbufferIndices[PresentIndex]}; + VkPresentInfoKHR info = {}; + info.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR; + info.waitSemaphoreCount = 1; + info.pWaitSemaphores = &g_RenderCompleteSemaphore[PresentIndex]; + info.swapchainCount = 1; + info.pSwapchains = swapchains; + info.pImageIndices = indices; + err = vkQueuePresentKHR(g_Queue, &info); + check_vk_result(err); + + g_FrameIndex = (g_FrameIndex + 1) % IMGUI_VK_QUEUED_FRAMES; } static void error_callback(int error, const char* description) @@ -660,6 +682,18 @@ int main(int, char**) bool show_another_window = false; ImVec4 clear_color = ImColor(114, 144, 154); + // When IMGUI_UNLIMITED_FRAME_RATE is defined we render into latest image acquired from the swapchain + // but we display the image which was rendered before + // hence we must render once and increase the g_FrameIndex without presenting, which we do befor entering the render loop + // this is also the reason why frame_end() is split into frame_end() and frame_present(), the latter one not being called here +#ifdef IMGUI_UNLIMITED_FRAME_RATE + ImGui_ImplGlfwVulkan_NewFrame(); + frame_begin(); + ImGui_ImplGlfwVulkan_Render(g_CommandBuffer[g_FrameIndex]); + frame_end(); + g_FrameIndex = (g_FrameIndex + 1) % IMGUI_VK_QUEUED_FRAMES; +#endif // IMGUI_UNLIMITED_FRAME_RATE + // Main loop while (!glfwWindowShouldClose(window)) { @@ -702,6 +736,7 @@ int main(int, char**) frame_begin(); ImGui_ImplGlfwVulkan_Render(g_CommandBuffer[g_FrameIndex]); frame_end(); + frame_present(); } // Cleanup