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OpenSubdiv/examples/uvViewer/shader.glsl

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//
// Copyright 2013 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License
// and the following modification to it: Section 6 Trademarks.
// deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the
// trade names, trademarks, service marks, or product names of the
// Licensor and its affiliates, except as required for reproducing
// the content of the NOTICE file.
//
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
// either express or implied. See the License for the specific
// language governing permissions and limitations under the
// License.
//
#undef OSD_USER_VARYING_DECLARE
#define OSD_USER_VARYING_DECLARE \
vec3 color;
#undef OSD_USER_VARYING_ATTRIBUTE_DECLARE
#define OSD_USER_VARYING_ATTRIBUTE_DECLARE \
layout(location = 1) in vec3 color;
#undef OSD_USER_VARYING_PER_VERTEX
#define OSD_USER_VARYING_PER_VERTEX() \
outpt.color = color
#undef OSD_USER_VARYING_PER_CONTROL_POINT
#define OSD_USER_VARYING_PER_CONTROL_POINT(ID_OUT, ID_IN) \
outpt[ID_OUT].color = inpt[ID_IN].color
#undef OSD_USER_VARYING_PER_EVAL_POINT
#define OSD_USER_VARYING_PER_EVAL_POINT(UV, a, b, c, d) \
outpt.color = \
mix(mix(inpt[a].color, inpt[b].color, UV.x), \
mix(inpt[c].color, inpt[d].color, UV.x), UV.y)
//--------------------------------------------------------------
// Vertex Shader
//--------------------------------------------------------------
#ifdef VERTEX_SHADER
layout (location=0) in vec4 position;
OSD_USER_VARYING_ATTRIBUTE_DECLARE
out block {
OutputVertex v;
OSD_USER_VARYING_DECLARE
} outpt;
void main()
{
outpt.v.position = ModelViewMatrix * position;
OSD_USER_VARYING_PER_VERTEX();
}
#endif
//--------------------------------------------------------------
// Geometry Shader
//--------------------------------------------------------------
#ifdef GEOMETRY_SHADER
#ifdef PRIM_QUAD
layout(lines_adjacency) in;
#define EDGE_VERTS 4
#endif // PRIM_QUAD
#ifdef PRIM_TRI
layout(triangles) in;
#define EDGE_VERTS 3
#endif // PRIM_TRI
layout(triangle_strip, max_vertices = EDGE_VERTS) out;
in block {
OutputVertex v;
OSD_USER_VARYING_DECLARE
} inpt[EDGE_VERTS];
out block {
OutputVertex v;
noperspective out vec4 edgeDistance;
OSD_USER_VARYING_DECLARE
} outpt;
void emit(int index, vec3 normal)
{
outpt.v.position = inpt[index].v.position;
#ifdef SMOOTH_NORMALS
outpt.v.normal = inpt[index].v.normal;
#else
outpt.v.normal = normal;
#endif
#ifdef LOOP // ----- scheme : LOOP
vec2 uv;
OSD_COMPUTE_FACE_VARYING_TRI_2(uv, /*fvarOffste=*/0, index);
#else // ----- scheme : CATMARK / BILINEAR
#ifdef UNIFORM_SUBDIVISION
vec2 quadst[4] = vec2[](vec2(0,0), vec2(1,0), vec2(1,1), vec2(0,1));
vec2 st = quadst[index];
#else
vec2 st = inpt[index].v.tessCoord;
#endif
vec2 uv;
OSD_COMPUTE_FACE_VARYING_2(uv, /*fvarOffset=*/0, st);
#endif // ------ scheme
outpt.color = vec3(uv.s, uv.t, 0);
#ifdef GEOMETRY_UV_VIEW
uv = 2 * uv - vec2(1);
gl_Position = UvViewMatrix * vec4(uv.s, uv.y, 0, 1);
#else
gl_Position = ProjectionMatrix * inpt[index].v.position;
#endif
EmitVertex();
}
#if defined(GEOMETRY_OUT_WIRE) || defined(GEOMETRY_OUT_LINE)
const float VIEWPORT_SCALE = 512.0;
float edgeDistance(vec4 p, vec4 p0, vec4 p1)
{
return VIEWPORT_SCALE *
abs((p.x - p0.x) * (p1.y - p0.y) -
(p.y - p0.y) * (p1.x - p0.x)) / length(p1.xy - p0.xy);
}
void emit(int index, vec3 normal, vec4 edgeVerts[EDGE_VERTS])
{
outpt.edgeDistance[0] =
edgeDistance(edgeVerts[index], edgeVerts[0], edgeVerts[1]);
outpt.edgeDistance[1] =
edgeDistance(edgeVerts[index], edgeVerts[1], edgeVerts[2]);
#ifdef PRIM_TRI
outpt.edgeDistance[2] =
edgeDistance(edgeVerts[index], edgeVerts[2], edgeVerts[0]);
#endif
#ifdef PRIM_QUAD
outpt.edgeDistance[2] =
edgeDistance(edgeVerts[index], edgeVerts[2], edgeVerts[3]);
outpt.edgeDistance[3] =
edgeDistance(edgeVerts[index], edgeVerts[3], edgeVerts[0]);
#endif
emit(index, normal);
}
#endif
void main()
{
gl_PrimitiveID = gl_PrimitiveIDIn;
#ifdef PRIM_QUAD
vec3 A = (inpt[0].v.position - inpt[1].v.position).xyz;
vec3 B = (inpt[3].v.position - inpt[1].v.position).xyz;
vec3 C = (inpt[2].v.position - inpt[1].v.position).xyz;
vec3 n0 = normalize(cross(B, A));
#if defined(GEOMETRY_OUT_WIRE) || defined(GEOMETRY_OUT_LINE)
vec4 edgeVerts[EDGE_VERTS];
edgeVerts[0] = ProjectionMatrix * inpt[0].v.position;
edgeVerts[1] = ProjectionMatrix * inpt[1].v.position;
edgeVerts[2] = ProjectionMatrix * inpt[2].v.position;
edgeVerts[3] = ProjectionMatrix * inpt[3].v.position;
edgeVerts[0].xy /= edgeVerts[0].w;
edgeVerts[1].xy /= edgeVerts[1].w;
edgeVerts[2].xy /= edgeVerts[2].w;
edgeVerts[3].xy /= edgeVerts[3].w;
emit(0, n0, edgeVerts);
emit(1, n0, edgeVerts);
emit(3, n0, edgeVerts);
emit(2, n0, edgeVerts);
#else
emit(0, n0);
emit(1, n0);
emit(3, n0);
emit(2, n0);
#endif
#endif // PRIM_QUAD
#ifdef PRIM_TRI
vec3 A = (inpt[1].v.position - inpt[0].v.position).xyz;
vec3 B = (inpt[2].v.position - inpt[0].v.position).xyz;
vec3 n0 = normalize(cross(B, A));
#if defined(GEOMETRY_OUT_WIRE) || defined(GEOMETRY_OUT_LINE)
vec4 edgeVerts[EDGE_VERTS];
edgeVerts[0] = ProjectionMatrix * inpt[0].v.position;
edgeVerts[1] = ProjectionMatrix * inpt[1].v.position;
edgeVerts[2] = ProjectionMatrix * inpt[2].v.position;
edgeVerts[0].xy /= edgeVerts[0].w;
edgeVerts[1].xy /= edgeVerts[1].w;
edgeVerts[2].xy /= edgeVerts[2].w;
emit(0, n0, edgeVerts);
emit(1, n0, edgeVerts);
emit(2, n0, edgeVerts);
#else
emit(0, n0);
emit(1, n0);
emit(2, n0);
#endif
#endif // PRIM_TRI
EndPrimitive();
}
#endif
//--------------------------------------------------------------
// Fragment Shader
//--------------------------------------------------------------
#ifdef FRAGMENT_SHADER
in block {
OutputVertex v;
noperspective in vec4 edgeDistance;
OSD_USER_VARYING_DECLARE
} inpt;
out vec4 outColor;
vec4
edgeColor(vec4 Cfill, vec4 edgeDistance)
{
#if defined(GEOMETRY_OUT_WIRE) || defined(GEOMETRY_OUT_LINE)
#ifdef PRIM_TRI
float d =
min(inpt.edgeDistance[0], min(inpt.edgeDistance[1], inpt.edgeDistance[2]));
#endif
#ifdef PRIM_QUAD
float d =
min(min(inpt.edgeDistance[0], inpt.edgeDistance[1]),
min(inpt.edgeDistance[2], inpt.edgeDistance[3]));
#endif
vec4 Cedge = vec4(1.0, 1.0, 0.0, 1.0);
float p = exp2(-2 * d * d);
#if defined(GEOMETRY_OUT_WIRE)
if (p < 0.25) discard;
#endif
Cfill.rgb = mix(Cfill.rgb, Cedge.rgb, p);
#endif
return Cfill;
}
#if defined(PRIM_QUAD) || defined(PRIM_TRI)
void
main()
{
#ifdef GEOMETRY_UV_VIEW
outColor = vec4(edgeColor(vec4(0.5), inpt.edgeDistance));
return;
#else
vec3 N = (gl_FrontFacing ? inpt.v.normal : -inpt.v.normal);
// generating a checkerboard pattern
int checker = int(floor(20*inpt.color.r)+floor(20*inpt.color.g))&1;
vec4 color = vec4(inpt.color.rg*checker, 1-checker, 1);
#if defined(GEOMETRY_OUT_WIRE) || defined(GEOMETRY_OUT_LINE)
color = edgeColor(color, inpt.edgeDistance);
#endif
outColor = color;
#endif
}
#endif
#endif