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);
 
     GLint last_texture, last_unpack_buffer;
 
@@ -128,7 +128,7 @@ 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);
@@ -269,7 +269,7 @@ 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 =
@@ -280,7 +280,7 @@ 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 =
@@ -290,7 +290,7 @@ 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";
 
     SPDLOG_DEBUG("glsl_version: {}", glsl_version);

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

@@ -713,16 +713,16 @@ static void check_fonts(struct swapchain_data* data)
       create_fonts(data->font_atlas, instance_data->params, data->sw_stats.font1, data->sw_stats.font_text);
       unsigned char* pixels;
       int width, height;
-      data->font_atlas->GetTexDataAsAlpha8(&pixels, &width, &height);
+      data->font_atlas->GetTexDataAsRGBA32(&pixels, &width, &height);
 
       // wait for rendering to complete, if any
       device_data->vtable.DeviceWaitIdle(device_data->device);
       shutdown_swapchain_font(data);
 
       if (desc_set)
-         create_image(data, desc_set, width, height, VK_FORMAT_R8_UNORM, data->font_image, data->font_mem, data->font_image_view);
+         create_image(data, desc_set, width, height, VK_FORMAT_R8G8B8A8_UNORM, data->font_image, data->font_mem, data->font_image_view);
       else
-         desc_set = create_image_with_desc(data, width, height, VK_FORMAT_R8_UNORM, data->font_image, data->font_mem, data->font_image_view);
+         desc_set = create_image_with_desc(data, width, height, VK_FORMAT_R8G8B8A8_UNORM, data->font_image, data->font_mem, data->font_image_view);
 
       data->font_atlas->SetTexID((ImTextureID)desc_set);
       data->font_uploaded = false;
@@ -744,8 +744,8 @@ static void ensure_swapchain_fonts(struct swapchain_data *data,
    data->font_uploaded = true;
    unsigned char* pixels;
    int width, height;
-   data->font_atlas->GetTexDataAsAlpha8(&pixels, &width, &height);
-   size_t upload_size = width * height * 1 * sizeof(char);
+   data->font_atlas->GetTexDataAsRGBA32(&pixels, &width, &height);
+   size_t upload_size = width * height * 4 * sizeof(char);
    upload_image_data(device_data, command_buffer, pixels, upload_size, width, height, data->upload_font_buffer, data->upload_font_buffer_mem, data->font_image);
 }