main.tesse

#version 430 core

uniform mat4 model_mat;
uniform mat4 view_mat;
uniform mat4 proj_mat;

uniform sampler2D height;

layout (triangles, equal_spacing, ccw) in;
in vec2 TexCoord_ES_in[];
in float factor_ES_in[];

out vec2 TexCoord_FS_in;
out float factor_FS_in;
out vec3 interp_pos;
out vec4 interpc_pos;

vec2 interpolate2D(vec2 v0, vec2 v1, vec2 v2)                                                   
{                                                                                               
    return vec2(gl_TessCoord.x) * v0 + vec2(gl_TessCoord.y) * v1 + vec2(gl_TessCoord.z) * v2;   
} 

float interpolate(float v0, float v1, float v2)                                                   
{                                                                                               
    return gl_TessCoord.x * v0 + gl_TessCoord.y * v1 + gl_TessCoord.z * v2;   
} 

void main(void)
{
    vec4 pos = (gl_TessCoord.x * gl_in[0].gl_Position) +
                  (gl_TessCoord.y * gl_in[1].gl_Position) +
                  (gl_TessCoord.z * gl_in[2].gl_Position);
    interp_pos = pos.xyz;
    float offset = texture2D(height, interpolate2D(TexCoord_ES_in[0], TexCoord_ES_in[1], TexCoord_ES_in[2])).r;
    interpc_pos = proj_mat * view_mat * model_mat * vec4(pos.x, pos.y+offset, pos.z, 1.0);
    gl_Position = interpc_pos;
    TexCoord_FS_in = interpolate2D(TexCoord_ES_in[0], TexCoord_ES_in[1], TexCoord_ES_in[2]);
    factor_FS_in = factor_ES_in[0];//interpolate(factor_ES_in[0],factor_ES_in[1],factor_ES_in[2]);
}