LUT: add interpolation for the input blue color. #46

wysaid · Jun 3, 2019 · 54e836b · 54e836b
1 parent 62e3139
commit 54e836b
Showing 1 changed file with 17 additions and 6 deletions.
diff --git a/library/cge/src/filters/cgeLookupFilter.cpp b/library/cge/src/filters/cgeLookupFilter.cpp
@@ -1,4 +1,4 @@
-/*
+/*
 * cgeLookupFilter.cpp
 *
 *  Created on: 2016-7-4
@@ -8,7 +8,7 @@
 
 #include "cgeLookupFilter.h"
 
-static CGEConstString s_fsh = CGE_SHADER_STRING_PRECISION_M
+static CGEConstString s_fsh = CGE_SHADER_STRING_PRECISION_H
 (
 varying vec2 textureCoordinate;
 uniform sampler2D inputImageTexture;
@@ -24,11 +24,22 @@ void main()
 
 	float blue = color.b * 63.0;
 	vec2 coord1;
-	coord1.y = floor(blue / 8.0);
+	coord1.y = floor(floor(blue) / 8.0);
 	coord1.x = floor(blue) - (coord1.y * 8.0);
 
-	coord1 = coord1 * stepDis + halfPixel + (stepDis - perPixel) * color.xy;
-	gl_FragColor.rgb = texture2D(lookupTexture, coord1).rgb;
+    vec2 coord2;
+    coord2.y = floor(ceil(blue) / 8.0);
+    coord2.x = ceil(blue) - (coord2.y * 8.0);
+
+    vec2 stepsCalc = halfPixel + (stepDis - perPixel) * color.xy;
+
+	coord1 = coord1 * stepDis + stepsCalc;
+    coord2 = coord2 * stepDis + stepsCalc;
+
+    vec3 lutColor1 = texture2D(lookupTexture, coord1).rgb;
+    vec3 lutColor2 = texture2D(lookupTexture, coord2).rgb;
+
+	gl_FragColor.rgb = mix(lutColor1, lutColor2, fract(blue));
 	gl_FragColor.a = color.a;
 }
 );
@@ -63,4 +74,4 @@ namespace CGE
 		CGEImageFilterInterface::render2Texture(handler, srcTexture, vertexBufferID);
 	}
 
-}
+}