OpenCL Desaturate.jstalk

var src = """

__kernel void clDesaturate(read_write image2d_t src, read_write image2d_t dst, int width, int height) {
    
    int2 coord = (int2)(get_global_id(0), get_global_id(1));
    
    if (coord.x >= width || coord.y >= height) {
        return;
    }
    
    float4 color = read_imagef(src, CLK_FILTER_NEAREST, coord);
    float lum = (0.30f * color.x + 0.59f * color.y + 0.11f * color.z);
    float4 val = (float4)(lum, lum, lum, color.w);
    
    write_imagef(dst, coord, val);
}
""";

var context = [COSOpenCLContext new];
var program = [context programWithSource:src];
[program build];

var imagePath = [COSImageTools pathOfImageNamed:"llama"];
var kernel    = [program createKernel:"clDesaturate"];
var inBuffer  = [COSOpenCLImageBuffer instanceWithContext:context usingImageAtPath:imagePath];
var outBuffer = [COSOpenCLImageBuffer instanceWithContext:context width:[inBuffer width] height:[inBuffer height]];

[kernel setArgument:0 buffer:inBuffer];
[kernel setArgument:1 buffer:outBuffer];
[kernel setIntArgumentAtIndex:2 value:[inBuffer width]];
[kernel setIntArgumentAtIndex:3 value:[inBuffer height]];

[kernel enqueueCallWithGlobalSizeX:[inBuffer width] Y:[inBuffer height]];
[context finish];

[COSImageTools viewImageBuffer:outBuffer inWindowNamed:"OpenCL"];