[demos] port the excellent ctoy hello world demo

CMakeLists.txt

@@ -98,7 +98,7 @@ set(IMGUI_SRC
   ${DEPS_DIR}/cimgui/imgui/imgui_draw.cpp
   ${DEPS_DIR}/cimgui/imgui/imgui_widgets.cpp
   ${DEPS_DIR}/cimgui/imgui/examples/imgui_impl_glfw.cpp
-  ${DEPS_DIR}/cimgui/imgui/examples/imgui_impl_vulkan.cpp
+  ${SRC_DIR}/imgui/imgui_impl_vulkan.cpp
 )
 
 include_directories(

include/hot/guest/rawkit/image.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include <stdint.h>
+
+typedef struct rawkit_image {
+  void *pixels;
+  float width;
+  float height;
+  uint8_t channels;
+} rawkit_image;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+  const rawkit_image rawkit_load_image_relative_to_file(const char *from_file, const char *path);
+  #define rawkit_load_image(path) rawkit_load_image_relative_to_file(__FILE__, path)
+
+#ifdef __cplusplus
+}
+#endif

include/hot/guest/rawkit/rawkit.h

@@ -1,9 +1,13 @@
 
+#include "image.h"
 #include "serial.h"
 #include "string.h"
 #include "vulkan.h"
 
 #pragma once
+
+
 extern "C" {
   double rawkit_now();
+  float rawkit_randf();
 }

include/hot/guest/rawkit/vulkan.h

@@ -1,5 +1,11 @@
 #include <vulkan/vulkan.h>
+#include <cimgui.h>
 
 extern "C" {
   VkDevice rawkit_vulkan_device();
+  VkPhysicalDevice rawkit_vulkan_physical_device();
+  VkCommandBuffer rawkit_vulkan_command_buffer();
+  VkCommandPool rawkit_vulkan_command_pool();
+  ImTextureID rawkit_imgui_add_texture(VkSampler sampler, VkImageView image_view, VkImageLayout image_layout);
+  VkQueue rawkit_vulkan_queue();
 }