X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=padding_effect.frag;h=32ae84067503b395ecf6d27d9e90bcf75e5e091f;hp=4f1adc1fd257f54318f38a7ada6c3e296d29089f;hb=82071a94aaff95d2d29d077338085a8fb27e76d1;hpb=fbb1247a1996c6dbe54114eb5cc23dc79e17099c

diff --git a/padding_effect.frag b/padding_effect.frag
index 4f1adc1..32ae840 100644
--- a/padding_effect.frag
+++ b/padding_effect.frag
@@ -1,16 +1,24 @@
 uniform vec2 PREFIX(offset);
 uniform vec2 PREFIX(scale);
-uniform vec2 PREFIX(texcoord_min);
-uniform vec2 PREFIX(texcoord_max);
+
+uniform vec2 PREFIX(normalized_coords_to_texels);
+uniform vec2 PREFIX(offset_bottomleft);
+uniform vec2 PREFIX(offset_topright);
 
 vec4 FUNCNAME(vec2 tc) {
 	tc -= PREFIX(offset);
 	tc *= PREFIX(scale);
 
-	if (any(lessThan(tc, PREFIX(texcoord_min))) ||
-	    any(greaterThan(tc, PREFIX(texcoord_max)))) {
+	vec2 tc_texels = tc * PREFIX(normalized_coords_to_texels);
+	vec2 coverage_bottomleft = clamp(tc_texels + PREFIX(offset_bottomleft), 0.0f, 1.0f);
+	vec2 coverare_topright = clamp(PREFIX(offset_topright) - tc_texels, 0.0f, 1.0f);
+	vec2 coverage_both = coverage_bottomleft * coverare_topright;
+	float coverage = coverage_both.x * coverage_both.y;
+
+	if (coverage <= 0.0f) {
+		// Short-circuit in case the underlying function is expensive to call.
 		return PREFIX(border_color);
+	} else {
+		return mix(PREFIX(border_color), INPUT(tc), coverage);
 	}
-
-	return INPUT(tc);
 }