MapleShrine/mkxp
1
0
Fork 0
Code Issues 32 Pull requests 11 Projects Releases Wiki Activity

RGB rotation

Browse source
This commit is contained in:
Jonas Kulla 2016-10-04 15:16:57 +02:00
parent 0ec1fce4ac
commit 89bb3e85fd
5 changed files with 31 additions and 55 deletions
Download patch file Download diff file Expand all files Collapse all files

44
shader/hue.frag
View file

@ -1,48 +1,12 @@
uniform sampler2D inputTexture;
uniform float hueAdjust;
uniform sampler2D texture;
uniform lowp mat3 rotationMat;
varying vec2 v_texCoord;
void main ()
{
const vec4 kRGBToYPrime = vec4 (0.299, 0.587, 0.114, 0.0);
const vec4 kRGBToI = vec4 (0.596, -0.275, -0.321, 0.0);
const vec4 kRGBToQ = vec4 (0.212, -0.523, 0.311, 0.0);
vec4 color = texture2D (texture, v_texCoord.xy);
const vec4 kYIQToR = vec4 (1.0, 0.956, 0.621, 0.0);
const vec4 kYIQToG = vec4 (1.0, -0.272, -0.647, 0.0);
const vec4 kYIQToB = vec4 (1.0, -1.107, 1.704, 0.0);
/* Sample the input pixel */
vec4 color = texture2D (inputTexture, v_texCoord.xy);
/* Convert to YIQ */
float YPrime = dot (color, kRGBToYPrime);
float I = dot (color, kRGBToI);
float Q = dot (color, kRGBToQ);
/* Calculate the hue and chroma */
float hue = atan (Q, I);
float chroma = sqrt (I * I + Q * Q);
/* Make the user's adjustments */
hue += hueAdjust;
/* Remember old I and color */
float IOriginal = I;
vec4 coOriginal = color;
/* Convert back to YIQ */
Q = chroma * sin (hue);
I = chroma * cos (hue);
/* Convert back to RGB */
vec4 yIQ = vec4 (YPrime, I, Q, 0.0);
color.r = dot (yIQ, kYIQToR);
color.g = dot (yIQ, kYIQToG);
color.b = dot (yIQ, kYIQToB);
/* Save the result */
gl_FragColor = (IOriginal == 0.0) ? coOriginal : color;
gl_FragColor = vec4(rotationMat * color.rgb, color.a);
}