X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=sobel.frag;h=4fd12a37d40025241bd7bf8f5dab80eb63146fa2;hb=a75370343264a46e8addeff4973c7267e8ff2146;hp=e6b377f2a54fab04a99cef15549f2e4cec9cc567;hpb=bcdff7b1a183d7ff138a920997182d00f2decf0e;p=nageru

diff --git a/sobel.frag b/sobel.frag
index e6b377f..4fd12a3 100644
--- a/sobel.frag
+++ b/sobel.frag
@@ -4,7 +4,7 @@ in vec2 tc;
 out vec2 gradients;
 
 uniform sampler2D tex;
-uniform float inv_width, inv_height;
+uniform vec2 inv_image_size;
 
 void main()
 {
@@ -19,13 +19,13 @@ void main()
 	// Computing both at once allows us to get away with eight
 	// texture samples instead of twelve.
 
-	float x_left   = tc.x - inv_width;
+	float x_left   = tc.x - inv_image_size.x;
 	float x_mid    = tc.x; 
-	float x_right  = tc.x + inv_width;
+	float x_right  = tc.x + inv_image_size.x;
 
-	float y_top    = tc.y + inv_height;  // Note the bottom-left coordinate system.
+	float y_top    = tc.y + inv_image_size.y;  // Note the bottom-left coordinate system.
 	float y_mid    = tc.y;
-	float y_bottom = tc.y - inv_height;
+	float y_bottom = tc.y - inv_image_size.y;
  
 	float top_left     = texture(tex, vec2(x_left,  y_top)).x;
 	float left         = texture(tex, vec2(x_left,  y_mid)).x;