frames do be flying

Signed-off-by: Anna (navi) Figueiredo Gomes <navi@vlhl.dev>

1 files changed, 34 insertions, 26 deletions

diff --git a/main.c b/main.c
index 273f51f..2dddbd0 100644
--- a/main.c
+++ b/main.c
@@ -5,6 +5,8 @@
 #include <stdbool.h>
 #include <string.h>
 
+#define MAX_FRAMES_INFLIGHT 2
+
 static SDL_Window *window = NULL;
 static VkDebugUtilsMessengerEXT debug_messenger;
 static VkInstance instance = VK_NULL_HANDLE;
@@ -19,11 +21,12 @@ static VkExtent2D swapchain_extent;
 static VkRenderPass render_pass;
 static VkPipelineLayout pipeline_layout;
 static VkCommandPool command_pool;
-static VkCommandBuffer command_buffer;
+static VkCommandBuffer command_buffers[MAX_FRAMES_INFLIGHT];
 static VkPipeline graphics_pipeline;
-static VkSemaphore image_avail;
-static VkSemaphore render_finished;
-static VkFence in_flight_fence;
+static VkSemaphore image_avail[MAX_FRAMES_INFLIGHT];
+static VkSemaphore render_finished[MAX_FRAMES_INFLIGHT];
+static VkFence in_flight_fence[MAX_FRAMES_INFLIGHT];
+static uint32_t current_frame = 0;
 static struct {
 	size_t len;
 	VkImage data[];
@@ -129,9 +132,11 @@ bool found_queue_indx(struct queue_indices inds) {
 
 void cleanup() {
 	vkDeviceWaitIdle(gpu);
-	vkDestroySemaphore(gpu, image_avail, NULL);
-	vkDestroySemaphore(gpu, render_finished, NULL);
-	vkDestroyFence(gpu, in_flight_fence, NULL);
+	for (size_t i = 0; i < MAX_FRAMES_INFLIGHT; i++) {
+		vkDestroySemaphore(gpu, image_avail[i], NULL);
+		vkDestroySemaphore(gpu, render_finished[i], NULL);
+		vkDestroyFence(gpu, in_flight_fence[i], NULL);
+	}
 	vkDestroyCommandPool(gpu, command_pool, NULL);
 	for (size_t i = 0; i < swapchain_buffers->len; i++) {
 		vkDestroyFramebuffer(gpu, swapchain_buffers->data[i], NULL);
@@ -685,15 +690,15 @@ void create_command_pool() {
 	}
 }
 
-void create_command_buffer() {
+void create_command_buffers() {
 	VkCommandBufferAllocateInfo alloc_info = {
 		.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO,
 		.commandPool = command_pool,
 		.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY,
-		.commandBufferCount = 1
+		.commandBufferCount = MAX_FRAMES_INFLIGHT
 	};
 
-	VkResult res = vkAllocateCommandBuffers(gpu, &alloc_info, &command_buffer);
+	VkResult res = vkAllocateCommandBuffers(gpu, &alloc_info, command_buffers);
 	if (res != VK_SUCCESS) {
 		fputs("failed to allocate command buffer", stderr);
 		exit(-1);
@@ -762,12 +767,13 @@ void create_sync_objects() {
 		.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO,
 		.flags = VK_FENCE_CREATE_SIGNALED_BIT
 	};
-	if (vkCreateSemaphore(gpu, &semaphore_info, NULL, &image_avail) != VK_SUCCESS
-			|| vkCreateSemaphore(gpu, &semaphore_info, NULL, &render_finished) != VK_SUCCESS
-			|| vkCreateFence(gpu, &fence_info, NULL, &in_flight_fence) != VK_SUCCESS) {
-		fputs("failed to create semaphores and fence", stderr);
-		exit(-1);
-	}
+	for (size_t i = 0; i < MAX_FRAMES_INFLIGHT; i++)
+		if (vkCreateSemaphore(gpu, &semaphore_info, NULL, &image_avail[i]) != VK_SUCCESS
+				|| vkCreateSemaphore(gpu, &semaphore_info, NULL, &render_finished[i]) != VK_SUCCESS
+				|| vkCreateFence(gpu, &fence_info, NULL, &in_flight_fence[i]) != VK_SUCCESS) {
+			fputs("failed to create semaphores and fence", stderr);
+			exit(-1);
+		}
 }
 
 void init() {
@@ -806,21 +812,21 @@ void init() {
 	create_graphics_pipeline();
 	create_framebuffers();
 	create_command_pool();
-	create_command_buffer();
+	create_command_buffers();
 	create_sync_objects();
 }
 
 void draw() {
-	vkWaitForFences(gpu, 1, &in_flight_fence, VK_TRUE, UINT64_MAX);
-	vkResetFences(gpu, 1, &in_flight_fence);
+	vkWaitForFences(gpu, 1, &in_flight_fence[current_frame], VK_TRUE, UINT64_MAX);
+	vkResetFences(gpu, 1, &in_flight_fence[current_frame]);
 
 	uint32_t image_index;
-	vkAcquireNextImageKHR(gpu, swapchain, UINT64_MAX, image_avail, VK_NULL_HANDLE, &image_index);
-	vkResetCommandBuffer(command_buffer, 0);
-	record_command_buffer(command_buffer, image_index);
+	vkAcquireNextImageKHR(gpu, swapchain, UINT64_MAX, image_avail[current_frame], VK_NULL_HANDLE, &image_index);
+	vkResetCommandBuffer(command_buffers[current_frame], 0);
+	record_command_buffer(command_buffers[current_frame], image_index);
 
-	VkSemaphore wait_semaphores[] = { image_avail };
-	VkSemaphore signal_semaphores[] = { render_finished };
+	VkSemaphore wait_semaphores[] = { image_avail[current_frame] };
+	VkSemaphore signal_semaphores[] = { render_finished[current_frame] };
 	VkPipelineStageFlags wait_stages[] = { VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT };
 	VkSubmitInfo submit_info = {
 		.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO,
@@ -830,10 +836,10 @@ void draw() {
 		.signalSemaphoreCount = 1,
 		.pSignalSemaphores = signal_semaphores,
 		.commandBufferCount = 1,
-		.pCommandBuffers = &command_buffer
+		.pCommandBuffers = &command_buffers[current_frame]
 	};
 
-	VkResult res = vkQueueSubmit(gfx_queue, 1, &submit_info, in_flight_fence);
+	VkResult res = vkQueueSubmit(gfx_queue, 1, &submit_info, in_flight_fence[current_frame]);
 	if (res != VK_SUCCESS) {
 		fputs("failed to submit draw command buffer", stderr);
 		exit(-1);
@@ -850,6 +856,8 @@ void draw() {
 	};
 
 	vkQueuePresentKHR(present_queue, &present_info);
+
+	current_frame = (current_frame + 1) % MAX_FRAMES_INFLIGHT;
 }
 
 int main() {