Work on image_from_asset (refactor)

src/hello_imgui/image_from_asset.h

@@ -34,6 +34,9 @@ namespace HelloImGui
     void ImageFromAsset(const char *assetPath, const ImVec2& size = ImVec2(0, 0), const ImVec2& uv0 = ImVec2(0, 0), const ImVec2& uv1 = ImVec2(1,1), const ImVec4& tint_col = ImVec4(1,1,1,1), const ImVec4& border_col = ImVec4(0,0,0,0));
     bool ImageButtonFromAsset(const char *assetPath, const ImVec2& size = ImVec2(0, 0), const ImVec2& uv0 = ImVec2(0, 0),  const ImVec2& uv1 = ImVec2(1,1), int frame_padding = -1, const ImVec4& bg_col = ImVec4(0,0,0,0), const ImVec4& tint_col = ImVec4(1,1,1,1));
     ImTextureID ImTextureIdFromAsset(const char *assetPath);
+    ImVec2 ImageSizeFromAsset(const char *assetPath);
+
+    ImVec2 ImageProportionalSize(const ImVec2& askedSize, const ImVec2& imageSize);
 
     namespace internal
     {

src/hello_imgui/internal/backend_impls/image_vulkan.cpp

@@ -3,8 +3,6 @@
 
 #include "imgui.h"
 #include "hello_imgui/internal/backend_impls/rendering_vulkan.h"
-#include "hello_imgui/internal/stb_image.h"
-#include "hello_imgui/hello_imgui_assets.h"
 
 // Inspired from https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples#example-for-vulkan-users
 // WARNING: THIS IS ONE WAY TO DO THIS AMONG MANY, and provided for informational purpose.
@@ -29,25 +27,14 @@ namespace HelloImGui
         return 0xFFFFFFFF; // Unable to find memoryType
     }
 
-    ImageVk::ImageVk(const char *assetPath)
+    ImageVk::ImageVk(int width, int height, unsigned char* image_data_rgba)
     {
         VulkanGlobals& vkGlobals = GetVulkanGlobals();
 
         auto &self = *this;
 
-        // Load the image using stbi_load_from_memory
-        // ...
-        auto assetData = LoadAssetFileData(assetPath);
-        assert(assetData.data != nullptr);
-
-        unsigned char*image_data = stbi_load_from_memory(
-            (unsigned char *)assetData.data, (int)assetData.dataSize,
-            &self.Width, &self.Height, NULL, 4);
-
-        if (image_data == NULL) {
-            IM_ASSERT(false && "ImageVk: Failed to load image!");
-            return;
-        }
+        self.Width = width;
+        self.Height = height;
 
 
         // Calculate allocation size (in number of bytes)
@@ -145,7 +132,7 @@ namespace HelloImGui
             void* map = NULL;
             err = vkMapMemory(vkGlobals.Device, self.UploadBufferMemory, 0, image_size, 0, &map);
             VulkanSetup::check_vk_result(err);
-            memcpy(map, image_data, image_size);
+            memcpy(map, image_data_rgba, image_size);
             VkMappedMemoryRange range[1] = {};
             range[0].sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
             range[0].memory = self.UploadBufferMemory;
@@ -155,9 +142,6 @@ namespace HelloImGui
             vkUnmapMemory(vkGlobals.Device, self.UploadBufferMemory);
         }
 
-        // Release image memory using stb
-        stbi_image_free(image_data);
-
         // Create a command buffer that will perform following steps when hit in the command queue.
         // TODO: this works in the example, but may need input if this is an acceptable way to access the pool/create the command buffer.
         VkCommandPool command_pool = vkGlobals.ImGuiMainWindowData.Frames[vkGlobals.ImGuiMainWindowData.FrameIndex].CommandPool;

src/hello_imgui/internal/backend_impls/image_vulkan.h

@@ -8,13 +8,13 @@ namespace HelloImGui
 {
     struct ImageVk
     {
-        ImageVk(const char *assetPath);
+        ImageVk(int width, int height, unsigned char* image_data_rgba);
         ~ImageVk();
 
         VkDescriptorSet DS;         // Descriptor set: this is what you'll pass to Image()
         int             Width = 0;
         int             Height = 0;
-        int             Channels = 4;
+        static constexpr int Channels = 4; // We intentionally only support RGBA for now
 
         // Need to keep track of these to properly cleanup
         VkImageView     ImageView = nullptr;

src/hello_imgui/internal/backend_impls/rendering_vulkan.cpp

@@ -81,10 +81,6 @@ namespace HelloImGui
             VkResult err = vkDeviceWaitIdle(gVkGlobals.Device);
             HelloImGui::VulkanSetup::check_vk_result(err);
             ImGui_ImplVulkan_Shutdown();
-
-            //ImGui_ImplGlfw_Shutdown();
-            // ImGui::DestroyContext();
-
             HelloImGui::VulkanSetup::CleanupVulkanWindow();
             HelloImGui::VulkanSetup::CleanupVulkan();
         };

src/hello_imgui/internal/image_from_asset.cpp

@@ -1,86 +1,17 @@
-#ifdef HELLOIMGUI_HAS_OPENGL
-#include "hello_imgui/image_gl.h"
-
-#include <string>
-#include <unordered_map>
+#include "image_from_asset.h"
 
 namespace HelloImGui
 {
-std::unordered_map<std::string, ImageGlPtr> gImageFromAssetMap;
-
-void _LoadImageGl(const char *assetPath)
-{
-    if (gImageFromAssetMap.find(assetPath) == gImageFromAssetMap.end())
-        gImageFromAssetMap[assetPath] = ImageGl::FactorImage(assetPath);
-}
-
-void ImageFromAsset(const char *assetPath, const ImVec2 &size, const ImVec2 &uv0, const ImVec2 &uv1,
-                    const ImVec4 &tint_col, const ImVec4 &border_col)
-{
-    _LoadImageGl(assetPath);
-    gImageFromAssetMap.at(assetPath)->Draw(size, uv0, uv1, tint_col, border_col);
-}
-
-bool ImageButtonFromAsset(const char *assetPath, const ImVec2 &size, const ImVec2 &uv0, const ImVec2 &uv1,
-                          int frame_padding, const ImVec4 &bg_col, const ImVec4 &tint_col)
-{
-    _LoadImageGl(assetPath);
-    return gImageFromAssetMap.at(assetPath)->DrawButton(size, uv0, uv1, frame_padding, bg_col, tint_col);
-}
-
-ImTextureID ImTextureIdFromAsset(const char *assetPath)
-{
-    _LoadImageGl(assetPath);
-    return gImageFromAssetMap.at(assetPath)->imTextureId;
-}
-
-
-namespace internal
-{
-    void Free_ImageFromAssetMap()
+    ImVec2 ImageProportionalSize(const ImVec2& askedSize, const ImVec2& imageSize)
     {
-        // this function is called  by HelloImGui during the application's TearDown
-        // and will clear all asset images textures when the OpenGL context is still valid.
-        gImageFromAssetMap.clear();
+        ImVec2 r(askedSize);
+
+        if ((r.x == 0.f) && (r.y == 0.f))
+            r = imageSize;
+        else if (r.y == 0.f)
+            r.y = imageSize.y / imageSize.x * r.x;
+        else if (r.x == 0.f)
+            r.x = imageSize.x / imageSize.y * r.y;
+        return r;
     }
 }
-
-} // namespace HelloImGui
-
-
-#elif defined(HELLOIMGUI_HAS_VULKAN)
-// See image_from_asset_vulkan.cpp
-
-#else // #ifdef HELLOIMGUI_HAS_OPENGL
-
-#include "imgui.h"
-
-namespace HelloImGui
-{
-void ImageFromAsset(const char *assetPath, const ImVec2& size, const ImVec2& uv0, const ImVec2& uv1, const ImVec4& tint_col, const ImVec4& border_col)
-{
-    ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(1.f, 0.f, 0.f, 1.f));
-    ImGui::Text("ImageFromAsset requires OpenGL");
-    ImGui::PopStyleColor();
-}
-
-bool ImageButtonFromAsset(const char *assetPath, const ImVec2& size, const ImVec2& uv0, const ImVec2& uv1, int frame_padding, const ImVec4& bg_col, const ImVec4& tint_col)
-{
-    ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(1.f, 0.f, 0.f, 1.f));
-    ImGui::Text("ButtonFromAsset requires OpenGL");
-    ImGui::PopStyleColor();
-    return false;
-}
-
-ImTextureID ImTextureIDFromAsset(const char *assetPath)
-{
-    // Requires OpenGL!
-    return nullptr;
-}
-
-namespace internal
-{
-    void Free_ImageFromAssetMap() {}
-}
-} // namespace HelloImGui
-#endif // #ifdef HELLOIMGUI_HAS_OPENGL

src/hello_imgui/internal/image_from_asset_none.cpp

@@ -0,0 +1,41 @@
+#include "image_from_asset.h"
+
+
+#if !defined(HELLOIMGUI_HAS_VULKAN) && !defined(HELLOIMGUI_HAS_OPENGL)
+
+#include "imgui.h"
+
+namespace HelloImGui
+{
+    void ImageFromAsset(const char *assetPath, const ImVec2& size, const ImVec2& uv0, const ImVec2& uv1, const ImVec4& tint_col, const ImVec4& border_col)
+    {
+        ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(1.f, 0.f, 0.f, 1.f));
+        ImGui::Text("ImageFromAsset not available");
+        ImGui::PopStyleColor();
+    }
+
+    bool ImageButtonFromAsset(const char *assetPath, const ImVec2& size, const ImVec2& uv0, const ImVec2& uv1, int frame_padding, const ImVec4& bg_col, const ImVec4& tint_col)
+    {
+        ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(1.f, 0.f, 0.f, 1.f));
+        ImGui::Text("ButtonFromAsset not available");
+        ImGui::PopStyleColor();
+        return false;
+    }
+
+    ImTextureID ImTextureIDFromAsset(const char *assetPath)
+    {
+        // Requires OpenGL!
+        return nullptr;
+    }
+
+    ImVec2 ImageSizeFromAsset(const char *assetPath)
+    {
+        return ImVec2(0.f, 0.f);
+    }
+
+    namespace internal
+    {
+        void Free_ImageFromAssetMap() {}
+    }
+} // namespace HelloImGui
+#endif // #if !defined(HELLOIMGUI_HAS_VULKAN) && !defined(HELLOIMGUI_HAS_OPENGL)

src/hello_imgui/internal/image_from_asset_opengl.cpp

@@ -0,0 +1,59 @@
+#include "image_from_asset.h"
+
+#ifdef HELLOIMGUI_HAS_OPENGL
+#include "hello_imgui/image_gl.h"
+
+#include <string>
+#include <unordered_map>
+
+namespace HelloImGui
+{
+    static std::unordered_map<std::string, ImageGlPtr> gImageFromAssetMap;
+
+    void _LoadImageGl(const char *assetPath)
+    {
+        if (gImageFromAssetMap.find(assetPath) == gImageFromAssetMap.end())
+            gImageFromAssetMap[assetPath] = ImageGl::FactorImage(assetPath);
+    }
+
+    void ImageFromAsset(const char *assetPath, const ImVec2 &size, const ImVec2 &uv0, const ImVec2 &uv1,
+                        const ImVec4 &tint_col, const ImVec4 &border_col)
+    {
+        _LoadImageGl(assetPath);
+        gImageFromAssetMap.at(assetPath)->Draw(size, uv0, uv1, tint_col, border_col);
+    }
+
+    bool ImageButtonFromAsset(const char *assetPath, const ImVec2 &size, const ImVec2 &uv0, const ImVec2 &uv1,
+                              int frame_padding, const ImVec4 &bg_col, const ImVec4 &tint_col)
+    {
+        _LoadImageGl(assetPath);
+        return gImageFromAssetMap.at(assetPath)->DrawButton(size, uv0, uv1, frame_padding, bg_col, tint_col);
+    }
+
+    ImTextureID ImTextureIdFromAsset(const char *assetPath)
+    {
+        _LoadImageGl(assetPath);
+        return gImageFromAssetMap.at(assetPath)->imTextureId;
+    }
+
+    ImVec2 ImageSizeFromAsset(const char *assetPath)
+    {
+        _LoadImageGl(assetPath);
+        return gImageFromAssetMap.at(assetPath)->imageSize;
+    }
+
+
+    namespace internal
+    {
+        void Free_ImageFromAssetMap()
+        {
+            // this function is called  by HelloImGui during the application's TearDown
+            // and will clear all asset images textures when the OpenGL context is still valid.
+            gImageFromAssetMap.clear();
+        }
+    }
+
+} // namespace HelloImGui
+
+
+#endif // #ifdef HELLOIMGUI_HAS_OPENGL

src/hello_imgui/internal/image_from_asset_vulkan.cpp

@@ -2,37 +2,75 @@
 #include "hello_imgui/image_from_asset.h"
 #include "imgui.h"
 #include "hello_imgui/internal/backend_impls/image_vulkan.h"
+#include "hello_imgui/internal/stb_image.h"
+#include "hello_imgui/hello_imgui_assets.h"
 
 #include <string>
 #include <unordered_map>
 
 namespace HelloImGui
 {
-    std::unordered_map<std::string, ImageVkPtr> gImageFromAssetMap;
+    static std::unordered_map<std::string, ImageVkPtr> gImageFromAssetMap;
+
+
+    static ImageVkPtr _GetCachedImageVk(const char*assetPath)
+    {
+        if (gImageFromAssetMap.find(assetPath) != gImageFromAssetMap.end())
+            return gImageFromAssetMap.at(assetPath);
+
+        // Load the image using stbi_load_from_memory
+        auto assetData = LoadAssetFileData(assetPath);
+        assert(assetData.data != nullptr);
+        int width, height;
+        unsigned char*image_data_rgba = stbi_load_from_memory(
+            (unsigned char *)assetData.data, (int)assetData.dataSize,
+            &width, &height, NULL, 4);
+        if (image_data_rgba == NULL)
+        {
+            IM_ASSERT(false && "ImageVk: Failed to load image!");
+            return nullptr;
+        }
+
+        // Create and store the VkImage
+        if (gImageFromAssetMap.find(assetPath) == gImageFromAssetMap.end())
+            gImageFromAssetMap[assetPath] = std::make_shared<ImageVk>(width, height, image_data_rgba);
+
+        // Release image memory using stb
+        stbi_image_free(image_data_rgba);
+
+        return gImageFromAssetMap.at(assetPath);
+    }
 
     void ImageFromAsset(
         const char *assetPath, const ImVec2& size,
         const ImVec2& uv0, const ImVec2& uv1,
         const ImVec4& tint_col, const ImVec4& border_col)
     {
         auto textureId = ImTextureIdFromAsset(assetPath);
-
-        ImGui::Image(textureId, size, uv0, uv1, tint_col, border_col);
+        auto imageSize = ImageSizeFromAsset(assetPath);
+        ImVec2 displayedSize = ImageProportionalSize(size, imageSize);
+        ImGui::Image(textureId, displayedSize, uv0, uv1, tint_col, border_col);
     }
 
     bool ImageButtonFromAsset(const char *assetPath, const ImVec2& size, const ImVec2& uv0,  const ImVec2& uv1, int frame_padding, const ImVec4& bg_col, const ImVec4& tint_col)
     {
         auto textureId = ImTextureIdFromAsset(assetPath);
-        bool clicked = ImGui::ImageButton(textureId, size, uv0, uv1, frame_padding, bg_col, tint_col);
+        auto imageSize = ImageSizeFromAsset(assetPath);
+        ImVec2 displayedSize = ImageProportionalSize(size, imageSize);
+        bool clicked = ImGui::ImageButton(textureId, displayedSize, uv0, uv1, frame_padding, bg_col, tint_col);
         return clicked;
     }
 
     ImTextureID ImTextureIdFromAsset(const char *assetPath)
     {
-        if (gImageFromAssetMap.find(assetPath) == gImageFromAssetMap.end())
-                gImageFromAssetMap[assetPath] = std::make_shared<ImageVk>(assetPath);
+        auto cachedImage = _GetCachedImageVk(assetPath);
+        return (ImTextureID) cachedImage->DS;
+    }
 
-        return (ImTextureID) gImageFromAssetMap.at(assetPath)->DS;
+    ImVec2 ImageSizeFromAsset(const char *assetPath)
+    {
+        auto cachedImage = _GetCachedImageVk(assetPath);
+        return ImVec2((float)cachedImage->Width, (float)cachedImage->Height);
     }
 
     namespace internal

src/hello_imgui/internal/image_gl.cpp

@@ -44,18 +44,7 @@ ImageGl::~ImageGl()
 }
 
 
-ImVec2 ImageProportionalSize(const ImVec2& askedSize, const ImVec2& imageSize)
-{
-    ImVec2 r(askedSize);
-
-    if ((r.x == 0.f) && (r.y == 0.f))
-        r = imageSize;
-    else if (r.y == 0.f)
-        r.y = imageSize.y / imageSize.x * r.x;
-    else if (r.x == 0.f)
-        r.x = imageSize.x / imageSize.y * r.y;
-    return r;
-}
+ImVec2 ImageProportionalSize(const ImVec2& askedSize, const ImVec2& imageSize);
 
 
 void ImageGl::Draw(