89 lines
2.6 KiB
GLSL
89 lines
2.6 KiB
GLSL
#version 430 core
|
|
layout (points) in;
|
|
layout (triangle_strip, max_vertices = 11) out;
|
|
|
|
uniform vec2 lightPos;
|
|
uniform mat4 perpMat;
|
|
uniform mat4 worldMat;
|
|
|
|
vec2 lightPosa = lightPos;
|
|
|
|
vec4 shift (vec4 p)
|
|
{ return vec4 (p.xy + (200 * (p.xy-lightPosa)), 0 , 1);
|
|
}
|
|
float isLHS (vec2 startV, vec2 testV)
|
|
{
|
|
return sign( -startV.x * testV.y + startV.y * testV.x);
|
|
}
|
|
// construct a box with opening on bottom face
|
|
|
|
void main()
|
|
{
|
|
vec4 p1 = vec4 (gl_in[0].gl_Position.xy,0,1);
|
|
vec4 p2 = vec4 (gl_in[0].gl_Position.zw,0,1);
|
|
if (isLHS (p1.xy - lightPosa, p2.xy - lightPosa) < 0)
|
|
{
|
|
vec4 p3 = vec4 (p1.xy,-0.5,1);
|
|
vec4 p4 = vec4 (p2.xy,-0.5,1);
|
|
vec4 p5 = shift(p1);
|
|
vec4 p6 = shift(p2);
|
|
vec4 p7 = vec4 (p6.xy,-0.5,1);
|
|
vec4 p8 = vec4 (p5.xy,-0.5,1);
|
|
|
|
vec4 a1 = perpMat * p1;
|
|
vec4 a2 = perpMat * p2;
|
|
vec4 a3 = perpMat * p3;
|
|
vec4 a4 = perpMat * p4;
|
|
vec4 a5 = perpMat * p5;
|
|
vec4 a6 = perpMat * p6;
|
|
vec4 a7 = perpMat * p7;
|
|
vec4 a8 = perpMat * p8;
|
|
|
|
gl_Position = a4; EmitVertex();
|
|
gl_Position = a3; EmitVertex();
|
|
gl_Position = a7; EmitVertex();
|
|
gl_Position = a8; EmitVertex();
|
|
gl_Position = a5; EmitVertex();
|
|
gl_Position = a3; EmitVertex();
|
|
gl_Position = a1; EmitVertex();
|
|
gl_Position = a4; EmitVertex();
|
|
gl_Position = a2; EmitVertex();
|
|
gl_Position = a7; EmitVertex();
|
|
gl_Position = a6; EmitVertex();
|
|
// gl_Position = a5; EmitVertex();
|
|
EndPrimitive();
|
|
} else {}
|
|
}
|
|
|
|
// // void main()
|
|
// // {
|
|
// // vec4 frontL4 = worldMat * vec4(gl_in[0].gl_Position.xy, 0 ,1);
|
|
// // vec4 frontR4 = worldMat * vec4(gl_in[0].gl_Position.zw, 0 ,1);
|
|
// // vec2 frontL = frontL4.xy;
|
|
// // vec2 frontR = frontR4.xy;
|
|
// //
|
|
// // emitLine (frontR);
|
|
// // emitLine (frontL);
|
|
// // EndPrimitive();
|
|
// // }
|
|
// gl_Position = perspective * worldMat * p4; EmitVertex();
|
|
// gl_Position = perspective * worldMat * p3; EmitVertex();
|
|
// gl_Position = perspective * worldMat * p7; EmitVertex();
|
|
// gl_Position = perspective * worldMat * p8; EmitVertex();
|
|
// gl_Position = perspective * worldMat * p5; EmitVertex();
|
|
// gl_Position = perspective * worldMat * p3; EmitVertex();
|
|
// gl_Position = perspective * worldMat * p1; EmitVertex();
|
|
// gl_Position = perspective * worldMat * p4; EmitVertex();
|
|
// gl_Position = perspective * worldMat * p2; EmitVertex();
|
|
// gl_Position = perspective * worldMat * p7; EmitVertex();
|
|
// gl_Position = perspective * worldMat * p6; EmitVertex();
|
|
// gl_Position = perspective * worldMat * p5; EmitVertex();
|
|
//void emitLine (vec2 pa)
|
|
//{
|
|
// gl_Position = vec4 (pa, 0, 1);
|
|
// EmitVertex();
|
|
// gl_Position = shift (vec4 (pa,0,1)); //vec4 (pa + (200 * (pa - lightPosa)), 0 , 1);
|
|
// EmitVertex();
|
|
//}
|
|
|