There is supposedly an OpenGL ES2 target that does not support precision specifiers. However, the existing logic to detect this is currently broken in two ways:
1) There's a typo of the `#ifdef` as `#if`.
2) Checking for `GL_FRAGMENT_PRECISION_HIGH` can not be the correct way to detect this platform. Other targets, including some desktops, will also not have this defined (for various reasons).
Because some of the shader code is missing precision specifiers, and because a default is ONLY provided if `GL_FRAGMENT_PRECISION_HIGH` is set, these other targets break.
Instead of 'hard-coding' the prologue string into shaders in the C source, use our ability to provide a list of strings to `glShaderSource` instead, leaving the determination to run-time.
This commit closes https://github.com/libsdl-org/SDL/pull/6182
Simple DirectMedia Layer is a cross-platform development library designed
to provide low level access to audio, keyboard, mouse, joystick, and graphics
hardware via OpenGL and Direct3D. It is used by video playback software,
emulators, and popular games including Valve's award winning catalog
and many Humble Bundle games.
More extensive documentation is available in the docs directory, starting
with README.md
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