slang-shaders/border/sgba

These shader presets will allow you to apply a 320x240 Super Game Boy Advance border around a 240x160 input image from a Game Boy Advance core.

Please note that RetroArch's integer scaling function will not automatically set a correct integer scale for the output image, as it will only take the Game Boy Advance core's reported resolution of 240x160 into account, and not the output image's 320x240 resolution. You will need to set a custom viewport size, either with the Custom Ratio menu option or defining custom_viewport_width and custom_viewport_height in the config file, setting Aspect Ratio Index to "Custom", and enabling Integer Scaling to center the image automatically.

An example border is included, you can swap it out with another 320x240 Super Game Boy Advance border in png format with the center 240x160 transparent. The borders included with this shader were created by EndUser based on a concept by BLUEamnesiac.