Subversion Repositories gelsvn

#version 120

#extension GL_EXT_gpu_shader4 : enable

uniform vec2 WIN_SCALE;

varying in float n[6];

varying in vec4 diffuseIn[1];

varying vec4 diffuse;

noperspective varying float dist[6];

noperspective varying float n_frag;

float distance(vec2 p, vec2 p0, vec2 p1)

{

	vec2 v0 = p1-p0;

	vec2 v1 = p0-p;

	vec2 v2 = p1-p;

	float l = length(v0);

	return abs(v1.x*v2.y - v1.y * v2.x)/l;

}

vec2 p[6];

void compute_dist(int i, int N)

{

		for(int k=1;k<N-1;++k) {

			int j = (i+k)%N;

			dist[j] = distance(p[i],p[j],p[(j+1)%N]);

		}

		dist[i] = 0;

		dist[(i+N-1)%N] = 0;

}

void main(void)

{

	n_frag = n[0];

	int N = int(n[0]);

	for(int i=0;i<N;++i) {

		p[i] = WIN_SCALE * gl_PositionIn[i].xy/gl_PositionIn[i].w;

		dist[i] = 0;

	}

	for(int l=0;l<N;++l)

	{

		int i = (l%2==0) ? l/2 : N-(l+1)/2;

		compute_dist(i,N);

		diffuse = diffuseIn[i];

		gl_Position = gl_PositionIn[i];

		EmitVertex();

	}

	EndPrimitive();

}