From 3f432af82b13a88aca5f476139c8762fa8451019 Mon Sep 17 00:00:00 2001
From: Relintai <relintai@protonmail.com>
Date: Thu, 28 Jul 2022 11:34:02 +0200
Subject: [PATCH] Ported:  Disable Alpha throughout Glow and FXAA code in order
 to avoid issues with transparent viewports. - clayjohn
 https://github.com/godotengine/godot/commit/f92141be1393118873134deafb2e6777cadb583e

---
 drivers/gles2/shaders/tonemap.glsl | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/gles2/shaders/tonemap.glsl b/drivers/gles2/shaders/tonemap.glsl
index 0de42e896..59889ff09 100644
--- a/drivers/gles2/shaders/tonemap.glsl
+++ b/drivers/gles2/shaders/tonemap.glsl
@@ -235,13 +235,21 @@ vec4 apply_fxaa(vec4 color, vec2 uv_interp, vec2 pixel_size) {
 	const float FXAA_REDUCE_MIN = (1.0 / 128.0);
 	const float FXAA_REDUCE_MUL = (1.0 / 8.0);
 	const float FXAA_SPAN_MAX = 8.0;
+	const vec3 luma = vec3(0.299, 0.587, 0.114);
 
 	vec4 rgbNW = texture2DLod(source, uv_interp + vec2(-1.0, -1.0) * pixel_size, 0.0);
 	vec4 rgbNE = texture2DLod(source, uv_interp + vec2(1.0, -1.0) * pixel_size, 0.0);
 	vec4 rgbSW = texture2DLod(source, uv_interp + vec2(-1.0, 1.0) * pixel_size, 0.0);
 	vec4 rgbSE = texture2DLod(source, uv_interp + vec2(1.0, 1.0) * pixel_size, 0.0);
 	vec3 rgbM = color.rgb;
-	vec3 luma = vec3(0.299, 0.587, 0.114);
+
+#ifdef DISABLE_ALPHA
+	float lumaNW = dot(rgbNW.rgb, luma);
+	float lumaNE = dot(rgbNE.rgb, luma);
+	float lumaSW = dot(rgbSW.rgb, luma);
+	float lumaSE = dot(rgbSE.rgb, luma);
+	float lumaM = dot(rgbM, luma);
+#else
 	float lumaNW = dot(rgbNW.rgb, luma) - ((1.0 - rgbNW.a) / 8.0);
 	float lumaNE = dot(rgbNE.rgb, luma) - ((1.0 - rgbNE.a) / 8.0);
 	float lumaSW = dot(rgbSW.rgb, luma) - ((1.0 - rgbSW.a) / 8.0);
@@ -249,6 +257,7 @@ vec4 apply_fxaa(vec4 color, vec2 uv_interp, vec2 pixel_size) {
 	float lumaM = dot(rgbM, luma) - (color.a / 8.0);
 	float lumaMin = min(lumaM, min(min(lumaNW, lumaNE), min(lumaSW, lumaSE)));
 	float lumaMax = max(lumaM, max(max(lumaNW, lumaNE), max(lumaSW, lumaSE)));
+#endif
 
 	vec2 dir;
 	dir.x = -((lumaNW + lumaNE) - (lumaSW + lumaSE));
@@ -267,6 +276,13 @@ vec4 apply_fxaa(vec4 color, vec2 uv_interp, vec2 pixel_size) {
 	vec4 rgbA = 0.5 * (texture2DLod(source, uv_interp + dir * (1.0 / 3.0 - 0.5), 0.0) + texture2DLod(source, uv_interp + dir * (2.0 / 3.0 - 0.5), 0.0));
 	vec4 rgbB = rgbA * 0.5 + 0.25 * (texture2DLod(source, uv_interp + dir * -0.5, 0.0) + texture2DLod(source, uv_interp + dir * 0.5, 0.0));
 
+
+#ifdef DISABLE_ALPHA
+	float lumaB = dot(rgbB.rgb, luma);
+	vec4 color_output = ((lumaB < lumaMin) || (lumaB > lumaMax)) ? rgbA : rgbB;
+	return vec4(color_output.rgb, 1.0);
+#else
+
 	float lumaB = dot(rgbB.rgb, luma) - ((1.0 - rgbB.a) / 8.0);
 	vec4 color_output = ((lumaB < lumaMin) || (lumaB > lumaMax)) ? rgbA : rgbB;
 	if (color_output.a == 0.0) {
@@ -276,11 +292,16 @@ vec4 apply_fxaa(vec4 color, vec2 uv_interp, vec2 pixel_size) {
 	}
 
   return color_output;
+#endif
 }
 
 void main() {
   vec4 color = texture2DLod(source, uv_interp, 0.0);
 
+#ifdef DISABLE_ALPHA
+	color.a = 1.0;
+#endif
+
 #ifdef USE_FXAA
 	color = apply_fxaa(color, uv_interp, pixel_size);
 #endif