Support sqrt-transformed intermediates with compute shaders.

[movit] / footer.comp

diff --git a/footer.comp b/footer.comp
index 3ece901eb00e8de9fe4f1200101a19162b2b08fc..16197a63200019396c20661bc0edbb8128fad206 100644 (file)
--- a/footer.comp
+++ b/footer.comp
@@ -1,3 +1,10 @@
+// GLSL is pickier than the C++ preprocessor in if-testing for undefined
+// tokens; do some fixups here to keep it happy.
+
+#ifndef SQUARE_ROOT_TRANSFORMATION
+#define SQUARE_ROOT_TRANSFORMATION 0
+#endif
+
 void main()
 {
        INPUT();
@@ -10,10 +17,14 @@ vec4 tex2D(sampler2D s, vec2 coord)
 
 void cs_output(uvec2 coord, vec4 val)
 {
-       imageStore(outbuf, ivec2(coord), val);
+       cs_output(ivec2(coord), val);
 }
 
 void cs_output(ivec2 coord, vec4 val)
 {
+#if SQUARE_ROOT_TRANSFORMATION
+       // Make sure we don't give negative values to sqrt.
+       val.rgb = sqrt(max(val.rgb, 0.0));
+#endif
        imageStore(outbuf, coord, val);
 }