Files
loop/shader/shadow/cap.geom
T

48 lines
1.5 KiB
GLSL

#version 450 core
layout (triangles) in;
layout (invocations = 20) in;
layout (triangle_strip, max_vertices = 3) out;
layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
layout (std140, binding = 1) uniform LightsBlock
{
vec4 posBool[20];
vec4 colRad[20];
} ;
vec3 lightPos = posBool[gl_InvocationID].xyz ;
float theBool = posBool[gl_InvocationID].w;
// this code is duplicated in shadow/edge.geom, should not be changed on its own
vec4 projNear (vec4 pos)
{
// note we project to a specific height
// this is quite brittle, not ideal
vec3 dir = pos.xyz - lightPos ;
float a = (100 - pos.z) / dir.z ;
vec2 xy = (pos.xyz + a * dir).xy ;
return vec4 ( xy, 100 , 1) ;
}
void main()
{
vec4 p0 = gl_in[0].gl_Position ;
vec4 p1 = gl_in[1].gl_Position ;
vec4 p2 = gl_in[2].gl_Position ;
if ( //if Light Source is below all vertices, draw cap
// TODO think about when LS is beside the object
( p0.z - lightPos.z > 0 )
&& ( p1.z - lightPos.z > 0 )
&& ( p2.z - lightPos.z > 0 )
&& theBool == 1
)
{
// the front cap
vec4 v1 = vec4 (0,0,1,0) ;
gl_Layer = gl_InvocationID;
gl_Position = theMat * projNear(p0); EmitVertex();
gl_Layer = gl_InvocationID;
gl_Position = theMat * projNear(p1); EmitVertex();
gl_Layer = gl_InvocationID;
gl_Position = theMat * projNear(p2); EmitVertex();
EndPrimitive();
}
else {}
}