Merge pull request #54160 from Calinou/shadow-filter-use-early-bailing

drivers/gles3/shaders/scene.glsl

@@ -1263,7 +1263,20 @@ LIGHT_SHADER_CODE
 float sample_shadow(highp sampler2DShadow shadow, vec2 shadow_pixel_size, vec2 pos, float depth, vec4 clamp_rect) {
 #ifdef SHADOW_MODE_PCF_13 //ubershader-runtime
 
-	float avg = textureProj(shadow, vec4(pos, depth, 1.0));
+	float avg = textureProj(shadow, vec4(pos + vec2(shadow_pixel_size.x * 2.0, 0.0), depth, 1.0));
+	avg += textureProj(shadow, vec4(pos + vec2(-shadow_pixel_size.x * 2.0, 0.0), depth, 1.0));
+	avg += textureProj(shadow, vec4(pos + vec2(0.0, shadow_pixel_size.y * 2.0), depth, 1.0));
+	avg += textureProj(shadow, vec4(pos + vec2(0.0, -shadow_pixel_size.y * 2.0), depth, 1.0));
+	// Early bail if distant samples are fully shaded (or none are shaded) to improve performance.
+	if (avg <= 0.000001) {
+		// None shaded at all.
+		return 0.0;
+	} else if (avg >= 3.999999) {
+		// All fully shaded.
+		return 1.0;
+	}
+
+	avg += textureProj(shadow, vec4(pos, depth, 1.0));
 	avg += textureProj(shadow, vec4(pos + vec2(shadow_pixel_size.x, 0.0), depth, 1.0));
 	avg += textureProj(shadow, vec4(pos + vec2(-shadow_pixel_size.x, 0.0), depth, 1.0));
 	avg += textureProj(shadow, vec4(pos + vec2(0.0, shadow_pixel_size.y), depth, 1.0));
@@ -1272,10 +1285,6 @@ float sample_shadow(highp sampler2DShadow shadow, vec2 shadow_pixel_size, vec2 p
 	avg += textureProj(shadow, vec4(pos + vec2(-shadow_pixel_size.x, shadow_pixel_size.y), depth, 1.0));
 	avg += textureProj(shadow, vec4(pos + vec2(shadow_pixel_size.x, -shadow_pixel_size.y), depth, 1.0));
 	avg += textureProj(shadow, vec4(pos + vec2(-shadow_pixel_size.x, -shadow_pixel_size.y), depth, 1.0));
-	avg += textureProj(shadow, vec4(pos + vec2(shadow_pixel_size.x * 2.0, 0.0), depth, 1.0));
-	avg += textureProj(shadow, vec4(pos + vec2(-shadow_pixel_size.x * 2.0, 0.0), depth, 1.0));
-	avg += textureProj(shadow, vec4(pos + vec2(0.0, shadow_pixel_size.y * 2.0), depth, 1.0));
-	avg += textureProj(shadow, vec4(pos + vec2(0.0, -shadow_pixel_size.y * 2.0), depth, 1.0));
 	return avg * (1.0 / 13.0);
 #endif //ubershader-runtime