Exit light calculation early when pixel outside of light bounding rectangle

This hugely improves the performance of rendering PointLight2Ds

drivers/gles3/shaders/canvas.glsl

@@ -776,6 +776,12 @@ void main() {
 
 		vec2 tex_uv = (vec4(vertex, 0.0, 1.0) * mat4(light_array[light_base].texture_matrix[0], light_array[light_base].texture_matrix[1], vec4(0.0, 0.0, 1.0, 0.0), vec4(0.0, 0.0, 0.0, 1.0))).xy; //multiply inverse given its transposed. Optimizer removes useless operations.
 		vec2 tex_uv_atlas = tex_uv * light_array[light_base].atlas_rect.zw + light_array[light_base].atlas_rect.xy;
+
+		if (any(lessThan(tex_uv, vec2(0.0, 0.0))) || any(greaterThanEqual(tex_uv, vec2(1.0, 1.0)))) {
+			//if outside the light texture, light color is zero
+			continue;
+		}
+
 		vec4 light_color = textureLod(atlas_texture, tex_uv_atlas, 0.0);
 		vec4 light_base_color = light_array[light_base].color;
 
@@ -800,10 +806,6 @@ void main() {
 			light_color.rgb *= base_color.rgb;
 		}
 #endif
-		if (any(lessThan(tex_uv, vec2(0.0, 0.0))) || any(greaterThanEqual(tex_uv, vec2(1.0, 1.0)))) {
-			//if outside the light texture, light color is zero
-			light_color.a = 0.0;
-		}
 
 		if (bool(light_array[light_base].flags & LIGHT_FLAGS_HAS_SHADOW)) {
 			vec2 shadow_pos = (vec4(shadow_vertex, 0.0, 1.0) * mat4(light_array[light_base].shadow_matrix[0], light_array[light_base].shadow_matrix[1], vec4(0.0, 0.0, 1.0, 0.0), vec4(0.0, 0.0, 0.0, 1.0))).xy; //multiply inverse given its transposed. Optimizer removes useless operations.

servers/rendering/renderer_rd/shaders/canvas.glsl

@@ -665,6 +665,12 @@ void main() {
 
 		vec2 tex_uv = (vec4(vertex, 0.0, 1.0) * mat4(light_array.data[light_base].texture_matrix[0], light_array.data[light_base].texture_matrix[1], vec4(0.0, 0.0, 1.0, 0.0), vec4(0.0, 0.0, 0.0, 1.0))).xy; //multiply inverse given its transposed. Optimizer removes useless operations.
 		vec2 tex_uv_atlas = tex_uv * light_array.data[light_base].atlas_rect.zw + light_array.data[light_base].atlas_rect.xy;
+
+		if (any(lessThan(tex_uv, vec2(0.0, 0.0))) || any(greaterThanEqual(tex_uv, vec2(1.0, 1.0)))) {
+			//if outside the light texture, light color is zero
+			continue;
+		}
+
 		vec4 light_color = textureLod(sampler2D(atlas_texture, texture_sampler), tex_uv_atlas, 0.0);
 		vec4 light_base_color = light_array.data[light_base].color;
 
@@ -689,10 +695,6 @@ void main() {
 			light_color.rgb *= base_color.rgb;
 		}
 #endif
-		if (any(lessThan(tex_uv, vec2(0.0, 0.0))) || any(greaterThanEqual(tex_uv, vec2(1.0, 1.0)))) {
-			//if outside the light texture, light color is zero
-			light_color.a = 0.0;
-		}
 
 		if (bool(light_array.data[light_base].flags & LIGHT_FLAGS_HAS_SHADOW)) {
 			vec2 shadow_pos = (vec4(shadow_vertex, 0.0, 1.0) * mat4(light_array.data[light_base].shadow_matrix[0], light_array.data[light_base].shadow_matrix[1], vec4(0.0, 0.0, 1.0, 0.0), vec4(0.0, 0.0, 0.0, 1.0))).xy; //multiply inverse given its transposed. Optimizer removes useless operations.