I'm testing the triangle tessellation from the link http://prideout.net/blog/?p=48#shaders . All the shader are compiled correctly, but when I try to link the program using the command:
glLinkProgram(programID);
I got the following error:
Tessellation control info
(0): error C6029: No input primitive type
----------------------------------------
Tessellation evaluation info
(0): error c7005: No tessellation primitive mode specified
-----------------------------------------------------------
Geometry info
(0): error C6022: No input primitive type
(0): error C6029: No ouput primitive type
----------------------------------------
Not valid
It's so strange I declare output for TC Shader using command:
layout(vertices = 3) out;
And input layout for TE shader using command:
layout(triangles, equal_spacing, cw) in;
Why I still got this error? I hope to see you answer about it.
I put my shaders in below:
Vertex shader:
#version 410 core
in vec4 Position;
out vec3 vPosition;
void main()
{
vPosition = Position.xyz;
}
TC shader:
#version 410 core
layout(vertices = 3) out;
in vec3 vPosition[];
out vec3 tcPosition[];
#define ID gl_InvocationID
void main()
{
float TessLevelInner = 3;
float TessLevelOuter = 2;
tcPosition[ID] = vPosition[ID];
if (ID == 0) {
gl_TessLevelInner[0] = TessLevelInner;
gl_TessLevelOuter[0] = TessLevelOuter;
gl_TessLevelOuter[1] = TessLevelOuter;
gl_TessLevelOuter[2] = TessLevelOuter;
}
}
TE Shader:
#version 410 core
//TessEval
layout(triangles, equal_spacing, cw) in;
in vec3 tcPosition[];
out vec3 tePosition;
out vec3 tePatchDistance;
uniform mat4 Projection;
uniform mat4 Modelview;
void main()
{
vec3 p0 = gl_TessCoord.x * tcPosition[0];
vec3 p1 = gl_TessCoord.y * tcPosition[1];
vec3 p2 = gl_TessCoord.z * tcPosition[2];
tePatchDistance = gl_TessCoord;
tePosition = normalize(p0 + p1 + p2);
gl_Position = Projection * Modelview * vec4(tePosition, 1);
}
Geometry shader:
#version 410 core
//geometry shader
layout(triangles) in;
layout(triangle_strip, max_vertices = 3) out;
in vec3 tePosition[3];
in vec3 tePatchDistance[3];
out vec3 gFacetNormal;
out vec3 gPatchDistance;
out vec3 gTriDistance;
uniform mat4 Modelview;
uniform mat3 NormalMatrix;
void main()
{
vec3 A = tePosition[2] - tePosition[0];
vec3 B = tePosition[1] - tePosition[0];
gFacetNormal = NormalMatrix * normalize(cross(A, B));
gPatchDistance = tePatchDistance[0];
gTriDistance = vec3(1, 0, 0);
gl_Position = gl_in[0].gl_Position; EmitVertex();
gPatchDistance = tePatchDistance[1];
gTriDistance = vec3(0, 1, 0);
gl_Position = gl_in[1].gl_Position; EmitVertex();
gPatchDistance = tePatchDistance[2];
gTriDistance = vec3(0, 0, 1);
gl_Position = gl_in[2].gl_Position; EmitVertex();
EndPrimitive();
}
Fragment Shader:
#version 410 core
//fragment shader
out vec4 FragColor;
in vec3 gFacetNormal;
in vec3 gTriDistance;
in vec3 gPatchDistance;
in float gPrimitive;
uniform vec3 LightPosition;
float amplify(float d, float scale, float offset)
{
d = scale * d + offset;
d = clamp(d, 0, 1);
d = 1 - exp2(-2*d*d);
return d;
}
void main()
{
vec3 AmbientMaterial = vec3(0.04f, 0.04f, 0.04f);
vec3 DiffuseMaterial = vec3(0, 0.75, 0.75);
vec3 LightPosition = vec3(0.25, 0.25, 1);
vec3 N = normalize(gFacetNormal);
vec3 L = LightPosition;
float df = abs(dot(N, L));
vec3 color = AmbientMaterial + df * DiffuseMaterial;
float d1 = min(min(gTriDistance.x, gTriDistance.y), gTriDistance.z);
float d2 = min(min(gPatchDistance.x, gPatchDistance.y), gPatchDistance.z);
color = amplify(d1, 40, -0.5) * amplify(d2, 60, -0.5) * color;
FragColor = vec4(color, 1.0);
}