/// This file contains all opencl kernels for node-operation implementations 

// Global SAMPLERS
const sampler_t SAMPLER_NEAREST      = CLK_NORMALIZED_COORDS_FALSE | CLK_ADDRESS_CLAMP_TO_EDGE | CLK_FILTER_NEAREST;

__constant const int2 zero = {0,0};

// KERNEL --- BOKEH BLUR ---
__kernel void bokehBlurKernel(__read_only image2d_t boundingBox, __read_only image2d_t inputImage, 
                              __read_only image2d_t bokehImage, __write_only image2d_t output, 
                              int2 offsetInput, int2 offsetOutput, int radius, int step, int2 dimension, int2 offset) 
{
	int2 coords = {get_global_id(0), get_global_id(1)}; 
	coords += offset;
	float tempBoundingBox;
	float4 color = {0.0f,0.0f,0.0f,0.0f};
	float4 multiplyer = {0.0f,0.0f,0.0f,0.0f};
	float4 bokeh;
	const float radius2 = radius*2.0f;
	const int2 realCoordinate = coords + offsetOutput;

	tempBoundingBox = read_imagef(boundingBox, SAMPLER_NEAREST, coords).s0;

	if (tempBoundingBox > 0.0f) {
		const int2 bokehImageDim = get_image_dim(bokehImage);
		const int2 bokehImageCenter = bokehImageDim/2;
		const int2 minXY = max(realCoordinate - radius, zero);
		const int2 maxXY = min(realCoordinate + radius, dimension);
		int nx, ny;
		
		float2 uv;
		int2 inputXy;
		
		for (ny = minXY.y, inputXy.y = ny - offsetInput.y ; ny < maxXY.y ; ny +=step, inputXy.y+=step) {
			uv.y = ((realCoordinate.y-ny)/radius2)*bokehImageDim.y+bokehImageCenter.y;
			
			for (nx = minXY.x, inputXy.x = nx - offsetInput.x; nx < maxXY.x ; nx +=step, inputXy.x+=step) {
				uv.x = ((realCoordinate.x-nx)/radius2)*bokehImageDim.x+bokehImageCenter.x;
				bokeh = read_imagef(bokehImage, SAMPLER_NEAREST, uv);
				color += bokeh * read_imagef(inputImage, SAMPLER_NEAREST, inputXy);
				multiplyer += bokeh;
			}
		}
		color /= multiplyer;
		
	} else {
		int2 imageCoordinates = realCoordinate - offsetInput;
		color = read_imagef(inputImage, SAMPLER_NEAREST, imageCoordinates);
	}
	
	write_imagef(output, coords, color);
}

// KERNEL --- DILATE ---
__kernel void dilateKernel(__read_only image2d_t inputImage,  __write_only image2d_t output,
                           int2 offsetInput, int2 offsetOutput, int scope, int distanceSquared, int2 dimension, 
                           int2 offset)
{
	int2 coords = {get_global_id(0), get_global_id(1)}; 
	coords += offset;
	const int2 realCoordinate = coords + offsetOutput;

	const int2 minXY = max(realCoordinate - scope, zero);
	const int2 maxXY = min(realCoordinate + scope, dimension);
	
	float value = 0.0f;
	int nx, ny;
	int2 inputXy;
	
	for (ny = minXY.y, inputXy.y = ny - offsetInput.y ; ny < maxXY.y ; ny ++, inputXy.y++) {
		const float deltaY = (realCoordinate.y - ny);
		for (nx = minXY.x, inputXy.x = nx - offsetInput.x; nx < maxXY.x ; nx ++, inputXy.x++) {
			const float deltaX = (realCoordinate.x - nx);
			const float measuredDistance = deltaX*deltaX+deltaY*deltaY;
			if (measuredDistance <= distanceSquared) {
				value = max(value, read_imagef(inputImage, SAMPLER_NEAREST, inputXy).s0);
			}
		}
	}

	float4 color = {value,0.0f,0.0f,0.0f};
	write_imagef(output, coords, color);
}

// KERNEL --- DILATE ---
__kernel void erodeKernel(__read_only image2d_t inputImage,  __write_only image2d_t output,
                           int2 offsetInput, int2 offsetOutput, int scope, int distanceSquared, int2 dimension, 
                           int2 offset)
{
	int2 coords = {get_global_id(0), get_global_id(1)}; 
	coords += offset;
	const int2 realCoordinate = coords + offsetOutput;

	const int2 minXY = max(realCoordinate - scope, zero);
	const int2 maxXY = min(realCoordinate + scope, dimension);
	
	float value = 1.0f;
	int nx, ny;
	int2 inputXy;
	
	for (ny = minXY.y, inputXy.y = ny - offsetInput.y ; ny < maxXY.y ; ny ++, inputXy.y++) {
		for (nx = minXY.x, inputXy.x = nx - offsetInput.x; nx < maxXY.x ; nx ++, inputXy.x++) {
			const float deltaX = (realCoordinate.x - nx);
			const float deltaY = (realCoordinate.y - ny);
			const float measuredDistance = deltaX*deltaX+deltaY*deltaY;
			if (measuredDistance <= distanceSquared) {
				value = min(value, read_imagef(inputImage, SAMPLER_NEAREST, inputXy).s0);
			}
		}
	}

	float4 color = {value,0.0f,0.0f,0.0f};
	write_imagef(output, coords, color);
}