pioneers/shaders/map/tessEval.shader

54 lines
1.7 KiB
GLSL

#version 330
#extension GL_ARB_tessellation_shader : require
layout(triangles, equal_spacing, cw) in;
in vec3 tcPosition[];
in vec4 tcColor[];
in vec3 tcNormal[];
out vec4 teColor;
smooth out vec3 tePosition;
smooth out vec3 teNormal;
out float fogDist;
smooth out float gmix; //mixture of gravel
//out vec3 tePatchDistance;
//constant projection matrix
uniform mat4 ProjectionMatrix;
uniform mat4 ViewMatrix;
uniform mat3 NormalMatrix;
void main()
{
//NORMAL
vec3 n0 = gl_TessCoord.x * tcNormal[0];
vec3 n1 = gl_TessCoord.y * tcNormal[1];
vec3 n2 = gl_TessCoord.z * tcNormal[2];
vec3 tessNormal = normalize(n0 + n1 + n2);
teNormal = NormalMatrix * tessNormal;
//POSITION
vec3 p0 = gl_TessCoord.x * tcPosition[0];
vec3 p1 = gl_TessCoord.y * tcPosition[1];
vec3 p2 = gl_TessCoord.z * tcPosition[2];
tePosition = p0 + p1 + p2;
//sin(a,b) = length(cross(a,b))
float i0 = (1-gl_TessCoord.x)*gl_TessCoord.x * length(cross(tcNormal[0],tessNormal));
float i1 = (1-gl_TessCoord.y)*gl_TessCoord.y * length(cross(tcNormal[1],tessNormal));
float i2 = (1-gl_TessCoord.z)*gl_TessCoord.z * length(cross(tcNormal[2],tessNormal));
float standout = i0+i1+i2;
tePosition = tePosition+tessNormal*standout;
gl_Position = ProjectionMatrix * ViewMatrix * vec4(tePosition, 1);
fogDist = gl_Position.z;
//COLOR-BLENDING
vec4 c0 = (1-exp(gl_TessCoord.x)) * tcColor[0];
vec4 c1 = (1-exp(gl_TessCoord.y)) * tcColor[1];
vec4 c2 = (1-exp(gl_TessCoord.z)) * tcColor[2];
teColor = (c0 + c1 + c2)/((1-exp(gl_TessCoord.x))+(1-exp(gl_TessCoord.y))+(1-exp(gl_TessCoord.z)));
//mix gravel based on incline (sin (normal,up))
gmix = length(cross(tessNormal, vec3(0,1,0)));
}