Clamp alpha for blur effect to mitigate image retention

This commit is contained in:
Mr-Wiseguy 2024-03-27 22:18:31 -04:00
parent 20c999e579
commit 7ff1c194e0

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@ -92,7 +92,14 @@ void Play_DrawMotionBlur(PlayState* this) {
// @recomp Scale alpha based on the target framerate so that the blur effect decays at an equivalent rate
// to how it does in the original game's framerate.
alpha = (s32)(recomp_powf(alpha / 255.0f, 20.0f / recomp_get_target_framerate(gFramerateDivisor)) * 255.0f);
s32 original_alpha = alpha;
f32 exponent = 20.0f / recomp_get_target_framerate(gFramerateDivisor);
f32 alpha_float = recomp_powf(alpha / 255.0f, exponent);
// Clamp to an alpha of 0.9, which ensures that the output color converges to within a reasonable delta
// of the target color when using an R8G8B8A8 framebuffer as RT64 currently does.
// Not clamping leads to image retention at high framerates.
alpha_float = MIN(alpha_float, 0.9f);
alpha = (s32)(alpha_float * 255.0f);
if (sMotionBlurStatus == MOTION_BLUR_PROCESS) {
func_80170AE0(&this->pauseBgPreRender, &gfx, alpha);