improved efficiency by precalculating more values

git-svn-id: https://xbmc.svn.sourceforge.net/svnroot/xbmc/trunk@26775 568bbfeb-2a22-0410-94d2-cc84cf5bfa90

1 files changed, 23 insertions, 14 deletions

diff --git a/system/shaders/convolution-6x6.glsl b/system/shaders/convolution-6x6.glsl
index 2c5710d16a..5cb060c78b 100644
--- a/system/shaders/convolution-6x6.glsl
+++ b/system/shaders/convolution-6x6.glsl
@@ -10,19 +10,19 @@ vec4 weight(float pos)
 
 vec4 pixel(float xpos, float ypos)
 {
-  return texture2D(img, vec2(gl_TexCoord[0].x + xpos * stepx, gl_TexCoord[0].y + ypos * stepy));
+  return texture2D(img, vec2(xpos, ypos));
 }
 
-vec4 line (float ypos, float xf, vec4 linetaps1, vec4 linetaps2)
+vec4 line (float ypos, vec3 xpos1, vec3 xpos2, vec4 linetaps1, vec4 linetaps2)
 {
   vec4  pixels;
 
-  pixels  = pixel(-1.5 - xf, ypos) * linetaps1.r;
-  pixels += pixel(-0.5 - xf, ypos) * linetaps2.r;
-  pixels += pixel( 0.5 - xf, ypos) * linetaps1.g;
-  pixels += pixel( 1.5 - xf, ypos) * linetaps2.g;
-  pixels += pixel( 2.5 - xf, ypos) * linetaps1.b;
-  pixels += pixel( 3.5 - xf, ypos) * linetaps2.b;
+  pixels  = pixel(xpos1.r, ypos) * linetaps1.r;
+  pixels += pixel(xpos1.g, ypos) * linetaps2.r;
+  pixels += pixel(xpos1.b, ypos) * linetaps1.g;
+  pixels += pixel(xpos2.r, ypos) * linetaps2.g;
+  pixels += pixel(xpos2.g, ypos) * linetaps1.b;
+  pixels += pixel(xpos2.b, ypos) * linetaps2.b;
 
   return pixels;
 }
@@ -37,12 +37,21 @@ void main()
   vec4 columntaps1 = weight((1.0 - yf) / 2.0);
   vec4 columntaps2 = weight((1.0 - yf) / 2.0 + 0.5);
 
-  gl_FragColor  = line(-1.5 - yf, xf, linetaps1, linetaps2) * columntaps1.r;
-  gl_FragColor += line(-0.5 - yf, xf, linetaps1, linetaps2) * columntaps2.r;
-  gl_FragColor += line( 0.5 - yf, xf, linetaps1, linetaps2) * columntaps1.g;
-  gl_FragColor += line( 1.5 - yf, xf, linetaps1, linetaps2) * columntaps2.g;
-  gl_FragColor += line( 2.5 - yf, xf, linetaps1, linetaps2) * columntaps1.b;
-  gl_FragColor += line( 3.5 - yf, xf, linetaps1, linetaps2) * columntaps2.b;
+  vec3 xpos1 = vec3(
+      (-1.5 - xf) * stepx + gl_TexCoord[0].x,
+      (-0.5 - xf) * stepx + gl_TexCoord[0].x,
+      ( 0.5 - xf) * stepx + gl_TexCoord[0].x);
+  vec3 xpos2 = vec3(
+      ( 1.5 - xf) * stepx + gl_TexCoord[0].x,
+      ( 2.5 - xf) * stepx + gl_TexCoord[0].x,
+      ( 3.5 - xf) * stepx + gl_TexCoord[0].x);
+
+  gl_FragColor  = line((-1.5 - yf) * stepy + gl_TexCoord[0].y, xpos1, xpos2, linetaps1, linetaps2) * columntaps1.r;
+  gl_FragColor += line((-0.5 - yf) * stepy + gl_TexCoord[0].y, xpos1, xpos2, linetaps1, linetaps2) * columntaps2.r;
+  gl_FragColor += line(( 0.5 - yf) * stepy + gl_TexCoord[0].y, xpos1, xpos2, linetaps1, linetaps2) * columntaps1.g;
+  gl_FragColor += line(( 1.5 - yf) * stepy + gl_TexCoord[0].y, xpos1, xpos2, linetaps1, linetaps2) * columntaps2.g;
+  gl_FragColor += line(( 2.5 - yf) * stepy + gl_TexCoord[0].y, xpos1, xpos2, linetaps1, linetaps2) * columntaps1.b;
+  gl_FragColor += line(( 3.5 - yf) * stepy + gl_TexCoord[0].y, xpos1, xpos2, linetaps1, linetaps2) * columntaps2.b;
 
   gl_FragColor.a = gl_Color.a;
 }