Improve Vulkan demo (#717)

* demo: fix errors and warnings in GLFW Vulkan demo

* demo: improve resize handling in GLFW Vulkan demo

On my machine (x86_64 Linux, Wayland) VK_SUBOPTIMAL or
VK_OUT_OF_DATE_KHR were never returned so the resizing of the swapchain
never happened.

Fix by using GLFW's resize callback to detect a window resize and a
swapchain recreation. Vulkan tutorial uses the same approach.

fb_scale was never used in the Vulkan backend, so it was removed.

* demo: fix copy&paste typo in GLFW Vulkan demo

* demo: sync nuklear_glfw_vulkan.in.h with nuklear_glfw_vulkan.h

Over time people have not been noticing that the expected workflow is to
build nuklear_glfw_vulkan.h from nuklear_glfw_vulkan.in.h

Author: Detegr

demo/glfw_vulkan/main.c

@@ -139,8 +139,19 @@ struct vulkan_demo {
     VkDeviceMemory demo_texture_memory;
 
     VkFence render_fence;
+
+    bool framebuffer_resized;
 };
 
+static void glfw_framebuffer_resize_callback(GLFWwindow* window, int width, int height) {
+    struct vulkan_demo* demo;
+
+    (void)width;
+    (void)height;
+    demo = glfwGetWindowUserPointer(window);
+    demo->framebuffer_resized = true;
+}
+
 static void glfw_error_callback(int e, const char *d) {
     fprintf(stderr, "Error %d: %s\n", e, d);
 }
@@ -299,7 +310,7 @@ bool create_instance(struct vulkan_demo *demo) {
         if (i > 0) {
             printf(", ");
         }
-        printf(enabled_extensions[i]);
+        printf("%s\n", enabled_extensions[i]);
     }
     printf("\n");
     for (i = 0; i < enabled_extension_count; i++) {
@@ -1227,8 +1238,8 @@ bool create_graphics_pipeline(struct vulkan_demo *demo) {
     bool ret = false;
     char *vert_shader_code = NULL;
     char *frag_shader_code = NULL;
-    VkShaderModule vert_shader_module;
-    VkShaderModule frag_shader_module;
+    VkShaderModule vert_shader_module = VK_NULL_HANDLE;
+    VkShaderModule frag_shader_module = VK_NULL_HANDLE;
     FILE *fp;
     size_t file_len;
     VkPipelineShaderStageCreateInfo vert_shader_stage_info;
@@ -1246,8 +1257,9 @@ bool create_graphics_pipeline(struct vulkan_demo *demo) {
     VkPipelineLayoutCreateInfo pipeline_layout_info;
     VkResult result;
     VkGraphicsPipelineCreateInfo pipeline_info;
+    size_t read_result;
 
-    fp = fopen("shaders/demo.vert.spv", "r");
+    fp = fopen("shaders/demo.vert.spv", "rb");
     if (!fp) {
         fprintf(stderr, "Couldn't open shaders/demo.vert.spv\n");
         return false;
@@ -1256,15 +1268,19 @@ bool create_graphics_pipeline(struct vulkan_demo *demo) {
     file_len = ftell(fp);
     vert_shader_code = malloc(file_len);
     fseek(fp, 0, 0);
-    fread(vert_shader_code, 1, file_len, fp);
+    read_result = fread(vert_shader_code, file_len, 1, fp);
     fclose(fp);
+    if (read_result != 1) {
+        fprintf(stderr, "Could not read fragment shader\n");
+        goto cleanup;
+    }
 
     if (!create_shader_module(demo->device, vert_shader_code, file_len,
                               &vert_shader_module)) {
         goto cleanup;
     }
 
-    fp = fopen("shaders/demo.frag.spv", "r");
+    fp = fopen("shaders/demo.frag.spv", "rb");
     if (!fp) {
         fprintf(stderr, "Couldn't open shaders/demo.frag.spv\n");
         return false;
@@ -1273,8 +1289,12 @@ bool create_graphics_pipeline(struct vulkan_demo *demo) {
     file_len = ftell(fp);
     frag_shader_code = malloc(file_len);
     fseek(fp, 0, 0);
-    fread(frag_shader_code, 1, file_len, fp);
+    read_result = fread(frag_shader_code, file_len, 1, fp);
     fclose(fp);
+    if (read_result != 1) {
+        fprintf(stderr, "Could not read fragment shader\n");
+        goto cleanup;
+    }
 
     if (!create_shader_module(demo->device, frag_shader_code, file_len,
                               &frag_shader_module)) {
@@ -1862,6 +1882,8 @@ bool create_vulkan_demo(struct vulkan_demo *demo) {
         return false;
     }
 
+    demo->framebuffer_resized = false;
+
     return true;
 }
 
@@ -1876,6 +1898,9 @@ bool recreate_swap_chain(struct vulkan_demo *demo) {
     update_descriptor_sets(demo);
     nk_glfw3_resize(demo->swap_chain_image_extent.width,
                     demo->swap_chain_image_extent.height);
+
+    demo->framebuffer_resized = false;
+
     return true;
 }
 
@@ -1961,7 +1986,7 @@ bool render(struct vulkan_demo *demo, struct nk_colorf *bg,
 
     result = vkQueuePresentKHR(demo->present_queue, &present_info);
 
-    if (result == VK_ERROR_OUT_OF_DATE_KHR || result == VK_SUBOPTIMAL_KHR) {
+    if (result == VK_ERROR_OUT_OF_DATE_KHR || result == VK_SUBOPTIMAL_KHR || demo->framebuffer_resized) {
         recreate_swap_chain(demo);
     } else if (result != VK_SUCCESS) {
         fprintf(stderr, "vkQueuePresentKHR failed: %d\n", result);
@@ -2073,6 +2098,8 @@ int main(void) {
     memset(&demo, 0, sizeof(struct vulkan_demo));
     demo.win =
         glfwCreateWindow(WINDOW_WIDTH, WINDOW_HEIGHT, "Demo", NULL, NULL);
+    glfwSetWindowUserPointer(demo.win, &demo);
+    glfwSetFramebufferSizeCallback(demo.win, glfw_framebuffer_resize_callback);
 
     if (!create_vulkan_demo(&demo)) {
         fprintf(stderr, "failed to create vulkan demo!\n");
@@ -2192,6 +2219,10 @@ int main(void) {
                                   demo.image_available, NULL, &image_index);
 
         if (result == VK_ERROR_OUT_OF_DATE_KHR) {
+            recreate_swap_chain(&demo);
+
+            /* If vkAcquireNextImageKHR does not successfully acquire an image,
+             * semaphore and fence are unaffected. */
             continue;
         }
         if (result != VK_SUCCESS && result != VK_SUBOPTIMAL_KHR) {

demo/glfw_vulkan/nuklear_glfw_vulkan.h

@@ -372,7 +372,6 @@ static struct nk_glfw {
     struct nk_glfw_device vulkan;
     struct nk_context ctx;
     struct nk_font_atlas atlas;
-    struct nk_vec2 fb_scale;
     unsigned int text[NK_GLFW_TEXT_MAX];
     int text_len;
     struct nk_vec2 scroll;
@@ -1179,8 +1178,6 @@ NK_API void nk_glfw3_resize(uint32_t framebuffer_width,
     struct nk_glfw_device *dev = &glfw.vulkan;
     glfwGetWindowSize(glfw.win, &glfw.width, &glfw.height);
     glfwGetFramebufferSize(glfw.win, &glfw.display_width, &glfw.display_height);
-    glfw.fb_scale.x = (float)glfw.display_width / (float)glfw.width;
-    glfw.fb_scale.y = (float)glfw.display_height / (float)glfw.height;
 
     nk_glfw3_destroy_render_resources(dev);
     nk_glfw3_create_render_resources(dev, framebuffer_width,
@@ -1264,7 +1261,7 @@ NK_API void nk_glfw3_new_frame(void) {
     for (i = 0; i < glfw.text_len; ++i)
         nk_input_unicode(ctx, glfw.text[i]);
 
-#ifdef NK_GLFW_GL4_MOUSE_GRABBING
+#ifdef NK_GLFW_VULKAN_MOUSE_GRABBING
     /* optional grabbing behavior */
     if (ctx->input.mouse.grab)
         glfwSetInputMode(glfw.win, GLFW_CURSOR, GLFW_CURSOR_HIDDEN);
@@ -1332,7 +1329,7 @@ NK_API void nk_glfw3_new_frame(void) {
 
     glfwGetCursorPos(win, &x, &y);
     nk_input_motion(ctx, (int)x, (int)y);
-#ifdef NK_GLFW_GL4_MOUSE_GRABBING
+#ifdef NK_GLFW_VULKAN_MOUSE_GRABBING
     if (ctx->input.mouse.grabbed) {
         glfwSetCursorPos(glfw.win, ctx->input.mouse.prev.x,
                          ctx->input.mouse.prev.y);

demo/glfw_vulkan/src/nuklear_glfw_vulkan.in.h

@@ -24,6 +24,7 @@ unsigned char nuklearshaders_nuklear_frag_spv[] = {};
 unsigned int nuklearshaders_nuklear_frag_spv_len = 0;
 // NUKLEAR_SHADERS_END
 
+#include <assert.h>
 #include <stddef.h>
 #include <string.h>
 #define GLFW_INCLUDE_VULKAN
@@ -71,7 +72,6 @@ NK_API void nk_glfw3_mouse_button_callback(GLFWwindow *win, int button,
  */
 #ifdef NK_GLFW_VULKAN_IMPLEMENTATION
 #undef NK_GLFW_VULKAN_IMPLEMENTATION
-#include <assert.h>
 #include <stdlib.h>
 
 #ifndef NK_GLFW_TEXT_MAX
@@ -149,13 +149,13 @@ static struct nk_glfw {
     struct nk_glfw_device vulkan;
     struct nk_context ctx;
     struct nk_font_atlas atlas;
-    struct nk_vec2 fb_scale;
     unsigned int text[NK_GLFW_TEXT_MAX];
     int text_len;
     struct nk_vec2 scroll;
     double last_button_click;
     int is_double_click_down;
     struct nk_vec2 double_click_pos;
+    float delta_time_seconds_last;
 } glfw;
 
 struct Mat4f {
@@ -955,8 +955,6 @@ NK_API void nk_glfw3_resize(uint32_t framebuffer_width,
     struct nk_glfw_device *dev = &glfw.vulkan;
     glfwGetWindowSize(glfw.win, &glfw.width, &glfw.height);
     glfwGetFramebufferSize(glfw.win, &glfw.display_width, &glfw.display_height);
-    glfw.fb_scale.x = (float)glfw.display_width / (float)glfw.width;
-    glfw.fb_scale.y = (float)glfw.display_height / (float)glfw.height;
 
     nk_glfw3_destroy_render_resources(dev);
     nk_glfw3_create_render_resources(dev, framebuffer_width,
@@ -1031,11 +1029,16 @@ NK_API void nk_glfw3_new_frame(void) {
     struct nk_context *ctx = &glfw.ctx;
     struct GLFWwindow *win = glfw.win;
 
+    /* update the timer */
+    float delta_time_now = (float)glfwGetTime();
+    glfw.ctx.delta_time_seconds = delta_time_now - glfw.delta_time_seconds_last;
+    glfw.delta_time_seconds_last = delta_time_now;
+
     nk_input_begin(ctx);
     for (i = 0; i < glfw.text_len; ++i)
         nk_input_unicode(ctx, glfw.text[i]);
 
-#ifdef NK_GLFW_GL4_MOUSE_GRABBING
+#ifdef NK_GLFW_VULKAN_MOUSE_GRABBING
     /* optional grabbing behavior */
     if (ctx->input.mouse.grab)
         glfwSetInputMode(glfw.win, GLFW_CURSOR, GLFW_CURSOR_HIDDEN);
@@ -1103,7 +1106,7 @@ NK_API void nk_glfw3_new_frame(void) {
 
     glfwGetCursorPos(win, &x, &y);
     nk_input_motion(ctx, (int)x, (int)y);
-#ifdef NK_GLFW_GL4_MOUSE_GRABBING
+#ifdef NK_GLFW_VULKAN_MOUSE_GRABBING
     if (ctx->input.mouse.grabbed) {
         glfwSetCursorPos(glfw.win, ctx->input.mouse.prev.x,
                          ctx->input.mouse.prev.y);