[vk, opengl] recognize and use ETC2 (if available) textures natively (#3237)

this makes it so VK and OGL backends map the NVIDIA's ETC2 into VK_FORMAT_ETC-whatever and GL_ETC-whatever remaps, instead of using the default fallback for AR8G8B8. in short, just make the ETC2 textures be submitted as ETC2 instead of being submit as A8R8G8B8.

Signed-off-by: lizzie lizzie@eden-emu.dev

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3237
Reviewed-by: Ghost <>
Reviewed-by: crueter <crueter@eden-emu.dev>

src/video_core/vulkan_common/vulkan_device.h

@@ -363,6 +363,11 @@ public:
         return features.features.textureCompressionBC;
     }
 
+    /// Returns true if ETC2 is natively supported.
+    bool IsOptimalEtc2Supported() const {
+        return features.features.textureCompressionETC2;
+    }
+
     /// Returns true if descriptor aliasing is natively supported.
     bool IsDescriptorAliasingSupported() const {
         return GetDriverID() != VK_DRIVER_ID_QUALCOMM_PROPRIETARY;