opengl es - Custom Shader with GPUImage and GLKIT IOS -

i have custom shader take 3 sampler2d uniform values , need pass them 3 mappings shown below each of texture. have created code follows extending gpuimage class.

#import "mappingshader.h" #import <glkit/glkit.h> nsstring *const kgpuimageatgmappingfragmentshaderstring = shader_string (  precision highp float;   uniform sampler2d inputimagetexture;  uniform sampler2d red;  uniform sampler2d green;  uniform sampler2d blue;  uniform float uamount;   varying vec2 texturecoordinate;   void main() {      vec4 color = texture2d(inputimagetexture, texturecoordinate);       vec2 indexred = vec2(color.r, 0.0);      vec4 redcolor = texture2d(red, indexred);       vec2 indexgreen = vec2(color.g, 0.0);      vec4 greencolor = texture2d(green, indexgreen);       vec2 indexblue = vec2(color.b, 0.0);      vec4 bluecolor = texture2d(blue, indexblue);       gl_fragcolor = mix(                         color,                         vec4(redcolor.r, greencolor.g, bluecolor.b, color.a),                         uamount);  }  );  @interface mappingshader() {     glint uamount, red, green, blue; } @end    @implementation mappingshader  @synthesize amount = _amount;  - (id)init; {      if (!(self = [super initwithfragmentshaderfromstring:kgpuimageatgmappingfragmentshaderstring]))     {         return nil;     }      red = [filterprogram uniformindex:@"inputimagetexture"];     green = [filterprogram uniformindex:@"green"];     blue = [filterprogram uniformindex:@"blue"];      glktextureinfo *redtexr;     nserror *error;     nsstring *filepath = [[nsbundle mainbundle] pathforresource:@"aladin" oftype:@"png"];      redtexr = [glktextureloader texturewithcontentsoffile:filepath options:nil error:&error];     glactivetexture(gl_texture0);     gluniform1i(red, 0);     glbindtexture(gl_texture_2d, redtexr.name);      uamount = [filterprogram uniformindex:@"uamount"];      self.amount = 0.5;     return self;   //    glteximage2d(gl_texture_2d, 0, gl_rgba, 300, 300, 0, gl_rgba, gl_array_buffer, <#const glvoid *pixels#>)  //    glktextureinfo *texs = [glktextureloader alloc] initwithsharegroup:<#(eaglsharegroup *)#> }  -(void)setamount:(cgfloat)amount {     _amount = amount;     [self setfloat:_amount foruniform:uamount program:filterprogram];   }  @end 

so please how should pass below values shader , resulted image. have tried glkit loader not able result.

"red" : [54,54,55,55,55,56,56,57,57,57,58,58,58,59,59,60,60,60,61,61,61,62,62,63,63,63,64,64,65,65,65,66,66,67,67,67,68,68,69,69,69,70,70,71,71,72,72,73,73,73,74,74,75,75,76,76,77,77,78,78,79,79,80,80,81,81,82,82,83,83,84,85,85,86,86,87,87,88,89,89,90,90,91,92,92,93,94,94,95,96,96,97,98,98,99,100,100,101,102,102,103,104,105,105,106,107,107,108,109,110,111,111,112,113,114,114,115,116,117,118,118,119,120,121,122,123,123,124,125,126,127,128,128,129,130,131,132,133,134,135,135,136,137,138,139,140,141,142,143,144,145,146,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184,185,186,187,188,189,191,192,193,194,195,196,197,198,199,200,201,202,203,204,205,207,208,209,210,211,212,213,214,215,216,217,219,220,221,222,223,224,225,226,227,228,230,231,232,233,234,235,236,237,238,239,241,242,243,244,245,246,247,248,249,251,252,253,254,255],                     "green" : [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,160,161,162,163,164,165,166,167,168,169,170,171,171,172,173,174,175,176,177,177,178,179,180,181,181,182,183,184,184,185,186,187,187,188,189,189,190,191,191,192,193,193,194,194,195,195,196,197,197,198,198,199,199,199,200,200,201,201,202,202,202,203,203,203,204,204,204,205,205,205,206,206,206,207,207,207,207,208,208,208,209,209,209,209,209,210,210,210,210,211,211,211,211,212,212,212],                     "blue" : [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,61,62,63,64,65,66,67,68,69,70,70,71,72,73,74,75,76,77,77,78,79,80,81,82,82,83,84,85,86,86,87,88,89,89,90,91,92,92,93,94,95,95,96,97,98,98,99,100,100,101,102,102,103,104,104,105,106,106,107,107,108,109,109,110,110,111,111,112,113,113,114,114,115,115,116,116,117,117,118,118,119,119,119,120,120,121,121,122,122,122,123,123,124,124,124,125,125,125,126,126,126,127,127,127,128,128,128,129,129,129,129,130,130,130,131,131,131,131,132,132,132,132,133,133,133,133,134,134,134,134,134,135,135,135,135,135,136,136,136,136,136,136,137,137,137,137,137,137,138,138,138,138,138,138,139,139,139,139,139,139,139,140,140,140,140,140,140,140,140,141,141,141,141,141,141,141,142,142,142,142,142,142,142,142,142,142,142,142,142,142,142,142,142,142] 

i able find solution this. can use gpuimagetonecurvefilter reference , pass rgb values array texture.