convert textures to rgba

images textures need rgba (to load alpha for example for decorations).
thus, this commit globally convert gl textures in rgba

Signed-off-by: Nicolas Adenis-Lamarre <nicolas.adenis.lamarre@gmail.com>

src/gl/gl_renderer.cpp

@@ -109,7 +109,7 @@ bool ImGui_ImplOpenGL3_CreateFontsTexture()
     ImGuiIO& io = ImGui::GetIO();
     unsigned char* pixels;
     int width, height;
-    io.Fonts->GetTexDataAsAlpha8(&pixels, &width, &height);
+    io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);
 
     // Upload texture to graphics system
     GLint last_texture;
@@ -122,7 +122,7 @@ bool ImGui_ImplOpenGL3_CreateFontsTexture()
     if (g_IsGLES || g_GlVersion >= 200)
         glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 
-    glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, pixels);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
 
     // Store our identifier
     io.Fonts->SetTexID((ImTextureID)(intptr_t)g_FontTexture);
@@ -261,7 +261,7 @@ static bool    ImGui_ImplOpenGL3_CreateDeviceObjects()
         "out vec4 Out_Color;\n"
         "void main()\n"
         "{\n"
-        "    Out_Color = Frag_Color * vec4(1, 1, 1, texture(Texture, Frag_UV.st).r);\n"
+        "    Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
         "}\n";
 
     const GLchar* fragment_shader_glsl_300_es =
@@ -272,7 +272,7 @@ static bool    ImGui_ImplOpenGL3_CreateDeviceObjects()
         "layout (location = 0) out vec4 Out_Color;\n"
         "void main()\n"
         "{\n"
-        "    Out_Color = Frag_Color * vec4(1, 1, 1, texture(Texture, Frag_UV.st).r);\n"
+        "    Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
         "}\n";
 
     const GLchar* fragment_shader_glsl_410_core =
@@ -282,7 +282,7 @@ static bool    ImGui_ImplOpenGL3_CreateDeviceObjects()
         "layout (location = 0) out vec4 Out_Color;\n"
         "void main()\n"
         "{\n"
-        "    Out_Color = Frag_Color * vec4(1, 1, 1, texture(Texture, Frag_UV.st).r);\n"
+        "    Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
         "}\n";
 
 #ifndef NDEBUG

src/overlay.frag

@@ -10,5 +10,5 @@ layout(location = 0) in struct{
 
 void main()
 {
-    fColor = In.Color * vec4(1, 1, 1, texture(sTexture, In.UV.st).r);
+    fColor = In.Color * texture(sTexture, In.UV.st);
 }

src/vulkan.cpp

@@ -832,20 +832,20 @@ static void check_fonts(struct device_data* device_data)
 
    unsigned char* pixels;
    int width, height;
-   device_data->font_atlas->GetTexDataAsAlpha8(&pixels, &width, &height);
+   device_data->font_atlas->GetTexDataAsRGBA32(&pixels, &width, &height);
 
    // wait for rendering to complete, if any
    VK_CHECK(device_data->vtable.DeviceWaitIdle(device_data->device));
    shutdown_device_font(device_data);
-   create_image(device_data, width, height, VK_FORMAT_R8_UNORM, device_data->font_img);
+   create_image(device_data, width, height, VK_FORMAT_R8G8B8A8_UNORM, device_data->font_img);
 
    SPDLOG_DEBUG("Default font tex size: {}x{}px", width, height);
    SPDLOG_DEBUG("Update font image descriptor {}", (void*)device_data->descriptor_set);
    update_image_descriptor(device_data, device_data->font_img.image_view, device_data->descriptor_set);
    device_data->font_atlas->SetTexID((ImTextureID)device_data->descriptor_set);
 
-   std::thread(submit_image_upload_cmd, device_data, &device_data->font_img, pixels, width * height * 1 * sizeof(char)).detach();
-//     submit_image_upload_cmd(device_data, &device_data->font_img, pixels, width * height * 1 * sizeof(char));
+   std::thread(submit_image_upload_cmd, device_data, &device_data->font_img, pixels, width * height * 4 * sizeof(char)).detach();
+//     submit_image_upload_cmd(device_data, &device_data->font_img, pixels, width * height * 4 * sizeof(char));
 }
 
 static void check_fonts(struct swapchain_data* data)