/***********************************************************************************************************************
*                                                                                                                      *
* libscopeprotocols                                                                                                    *
*                                                                                                                      *
* Copyright (c) 2012-2022 Andrew D. Zonenberg and contributors                                                         *
* All rights reserved.                                                                                                 *
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*      following disclaimer.                                                                                           *
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*      following disclaimer in the documentation and/or other materials provided with the distribution.                *
*                                                                                                                      *
*    * Neither the name of the author nor the names of any contributors may be used to endorse or promote products     *
*      derived from this software without specific prior written permission.                                           *
*                                                                                                                      *
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* POSSIBILITY OF SUCH DAMAGE.                                                                                          *
*                                                                                                                      *
***********************************************************************************************************************/

#version 430
#pragma shader_stage(compute)

layout(std430, binding=0) restrict readonly buffer buf_din
{
	float din[];
};

layout(std430, binding=1) restrict readonly buffer buf_fkernel
{
	float fkernel[];
};

layout(std430, binding=2) restrict writeonly buffer buf_dout
{
	float dout[];
};

layout(std430, push_constant) uniform constants
{
	uint imax;
	uint upsample_factor;
	uint kernel;
};

layout(local_size_x=64, local_size_y=1, local_size_z=1) in;

void main()
{
	if(gl_GlobalInvocationID.x >= imax)				//i
		return;
	if(gl_GlobalInvocationID.y >= upsample_factor)	//j
		return;

	uint start = 0;
	uint sstart = 0;
	if(gl_GlobalInvocationID.y > 0)
	{
		sstart = 1;
		start = upsample_factor - gl_GlobalInvocationID.y;
	}

	float f = 0;
	for(uint k = start; k<kernel; k += upsample_factor, sstart ++)
		f += fkernel[k] * din[gl_GlobalInvocationID.x + sstart];

	dout[gl_GlobalInvocationID.x*upsample_factor + gl_GlobalInvocationID.y] = f;
}
