procedural-3d-engine/shaders/glsl/tessellation/pntriangles.tese
2024-01-14 10:24:55 +01:00

89 lines
No EOL
2.9 KiB
GLSL

#version 450
// PN patch data
struct PnPatch
{
float b210;
float b120;
float b021;
float b012;
float b102;
float b201;
float b111;
float n110;
float n011;
float n101;
};
layout (binding = 0) uniform UBO
{
mat4 projection;
mat4 model;
float tessAlpha;
float tessLevel;
} ubo;
layout(triangles, fractional_odd_spacing, cw) in;
layout(location = 0) in vec3 iNormal[];
layout(location = 3) in vec2 iTexCoord[];
layout(location = 6) in PnPatch iPnPatch[];
layout(location = 0) out vec3 oNormal;
layout(location = 1) out vec2 oTexCoord;
#define uvw gl_TessCoord
void main()
{
vec3 uvwSquared = uvw * uvw;
vec3 uvwCubed = uvwSquared * uvw;
// extract control points
vec3 b210 = vec3(iPnPatch[0].b210, iPnPatch[1].b210, iPnPatch[2].b210);
vec3 b120 = vec3(iPnPatch[0].b120, iPnPatch[1].b120, iPnPatch[2].b120);
vec3 b021 = vec3(iPnPatch[0].b021, iPnPatch[1].b021, iPnPatch[2].b021);
vec3 b012 = vec3(iPnPatch[0].b012, iPnPatch[1].b012, iPnPatch[2].b012);
vec3 b102 = vec3(iPnPatch[0].b102, iPnPatch[1].b102, iPnPatch[2].b102);
vec3 b201 = vec3(iPnPatch[0].b201, iPnPatch[1].b201, iPnPatch[2].b201);
vec3 b111 = vec3(iPnPatch[0].b111, iPnPatch[1].b111, iPnPatch[2].b111);
// extract control normals
vec3 n110 = normalize(vec3(iPnPatch[0].n110, iPnPatch[1].n110, iPnPatch[2].n110));
vec3 n011 = normalize(vec3(iPnPatch[0].n011, iPnPatch[1].n011, iPnPatch[2].n011));
vec3 n101 = normalize(vec3(iPnPatch[0].n101, iPnPatch[1].n101, iPnPatch[2].n101));
// compute texcoords
oTexCoord = gl_TessCoord[2]*iTexCoord[0] + gl_TessCoord[0]*iTexCoord[1] + gl_TessCoord[1]*iTexCoord[2];
// normal
// Barycentric normal
vec3 barNormal = gl_TessCoord[2]*iNormal[0] + gl_TessCoord[0]*iNormal[1] + gl_TessCoord[1]*iNormal[2];
vec3 pnNormal = iNormal[0]*uvwSquared[2] + iNormal[1]*uvwSquared[0] + iNormal[2]*uvwSquared[1]
+ n110*uvw[2]*uvw[0] + n011*uvw[0]*uvw[1]+ n101*uvw[2]*uvw[1];
oNormal = ubo.tessAlpha*pnNormal + (1.0-ubo.tessAlpha) * barNormal;
// compute interpolated pos
vec3 barPos = gl_TessCoord[2]*gl_in[0].gl_Position.xyz
+ gl_TessCoord[0]*gl_in[1].gl_Position.xyz
+ gl_TessCoord[1]*gl_in[2].gl_Position.xyz;
// save some computations
uvwSquared *= 3.0;
// compute PN position
vec3 pnPos = gl_in[0].gl_Position.xyz*uvwCubed[2]
+ gl_in[1].gl_Position.xyz*uvwCubed[0]
+ gl_in[2].gl_Position.xyz*uvwCubed[1]
+ b210*uvwSquared[2]*uvw[0]
+ b120*uvwSquared[0]*uvw[2]
+ b201*uvwSquared[2]*uvw[1]
+ b021*uvwSquared[0]*uvw[1]
+ b102*uvwSquared[1]*uvw[2]
+ b012*uvwSquared[1]*uvw[0]
+ b111*6.0*uvw[0]*uvw[1]*uvw[2];
// final position and normal
vec3 finalPos = (1.0-ubo.tessAlpha)*barPos + ubo.tessAlpha*pnPos;
gl_Position = ubo.projection * ubo.model * vec4(finalPos,1.0);
}