103 lines
3.2 KiB
GLSL
103 lines
3.2 KiB
GLSL
layout(triangles) in;
|
|
layout(line_strip, max_vertices = 24) out;
|
|
|
|
in vec3 o_normal[];
|
|
in vec3 o_tangent[];
|
|
in vec3 o_bitangent[];
|
|
|
|
flat out vec4 o_color;
|
|
|
|
void main()
|
|
{
|
|
// colors for different type of new lines
|
|
vec4 edge_color = vec4(0.2, 0.1, 0.1, 1.0);
|
|
vec4 face_normal_color = vec4(0.5, 0.7, 0.2, 1.0);
|
|
vec4 normal_color = vec4(0.0, 1.0, 0.2, 1.0);
|
|
vec4 tangent_color = vec4(1.0, 0.3, 0.2, 1.0);
|
|
vec4 bitangent_color = vec4(0.0, 0.1, 1.0, 1.0);
|
|
|
|
// form two vectors from triangle
|
|
vec3 V0 = gl_in[0].gl_Position.xyz - gl_in[1].gl_Position.xyz;
|
|
vec3 V1 = gl_in[2].gl_Position.xyz - gl_in[1].gl_Position.xyz;
|
|
// calculate normal as perpendicular to two vectors of the triangle
|
|
vec3 V0_V1_crossed = cross(V1, V0);
|
|
float normal_scale = min(length(V0_V1_crossed) * 10.0, 0.25);
|
|
vec3 N = normalize(V0_V1_crossed);
|
|
|
|
// normals of each vertex of the triangle
|
|
vec3 nor[3];
|
|
nor[0] = o_normal[0].xyz;
|
|
nor[1] = o_normal[1].xyz;
|
|
nor[2] = o_normal[2].xyz;
|
|
|
|
// positions of each vertex of the triangle
|
|
// shifted a bit along normal
|
|
// so there won't be Z fighting when rendered over the mesh
|
|
vec4 pos[3];
|
|
pos[0] = u_projection_view_matrix *
|
|
vec4(gl_in[0].gl_Position.xyz + nor[0] * 0.01, 1.0);
|
|
pos[1] = u_projection_view_matrix *
|
|
vec4(gl_in[1].gl_Position.xyz + nor[1] * 0.01, 1.0);
|
|
pos[2] = u_projection_view_matrix *
|
|
vec4(gl_in[2].gl_Position.xyz + nor[2] * 0.01, 1.0);
|
|
|
|
// output normals, tangents and bitangents for each vertex of the triangle
|
|
for (int i=0; i < gl_in.length(); i++)
|
|
{
|
|
// get position of the vertex
|
|
vec3 P = gl_in[i].gl_Position.xyz;
|
|
|
|
// create normal for vertex
|
|
o_color = normal_color;
|
|
gl_Position = pos[i];
|
|
EmitVertex();
|
|
gl_Position = u_projection_view_matrix * vec4(P + o_normal[i].xyz
|
|
* normal_scale, 1.0);
|
|
EmitVertex();
|
|
EndPrimitive();
|
|
|
|
// create tangent for vertex
|
|
o_color = tangent_color;
|
|
gl_Position = pos[i];
|
|
EmitVertex();
|
|
gl_Position = u_projection_view_matrix *
|
|
vec4(P + o_tangent[i].xyz * normal_scale, 1.0);
|
|
EmitVertex();
|
|
EndPrimitive();
|
|
|
|
// create bitangent for vertex
|
|
o_color = bitangent_color;
|
|
gl_Position = pos[i];
|
|
EmitVertex();
|
|
gl_Position = u_projection_view_matrix * vec4(P +
|
|
o_bitangent[i].xyz * normal_scale, 1.0);
|
|
EmitVertex();
|
|
EndPrimitive();
|
|
}
|
|
|
|
// create edges for triangle
|
|
o_color = edge_color;
|
|
gl_Position = pos[0];
|
|
EmitVertex();
|
|
gl_Position = pos[1];
|
|
EmitVertex();
|
|
gl_Position = pos[2];
|
|
EmitVertex();
|
|
gl_Position = pos[0];
|
|
EmitVertex();
|
|
// end line strip after four added vertices, so we will get three lines
|
|
EndPrimitive();
|
|
|
|
// create normal for triangle
|
|
o_color = face_normal_color;
|
|
|
|
// position as arithmetic average
|
|
vec3 P = (gl_in[0].gl_Position.xyz + gl_in[1].gl_Position.xyz
|
|
+ gl_in[2].gl_Position.xyz) / 3.0;
|
|
gl_Position = u_projection_view_matrix * vec4(P, 1.0);
|
|
EmitVertex();
|
|
gl_Position = u_projection_view_matrix * vec4(P + N * normal_scale, 1.0);
|
|
EmitVertex();
|
|
EndPrimitive();
|
|
}
|