OpenSubdiv/opensubdiv/osd/glslPatchGregoryBasis.glsl
David G Yu f4a8cafe86 Sync'ed up GLSL and HLSL patch shader source.
Cleaned up the Legacy Gregory shader source by accessing buffer
data through helper functions.

Switched to performing tessellation in untransformed (object) space.
2015-05-21 09:56:25 -07:00

262 lines
7.1 KiB
GLSL

//
// Copyright 2015 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is 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 to comply with Section 4(c) of
// the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//
//----------------------------------------------------------
// Patches.VertexGregoryBasis
//----------------------------------------------------------
#ifdef OSD_PATCH_VERTEX_GREGORY_BASIS_SHADER
layout(location = 0) in vec4 position;
OSD_USER_VARYING_ATTRIBUTE_DECLARE
out block {
ControlVertex v;
OSD_USER_VARYING_DECLARE
} outpt;
void main()
{
outpt.v.position = position;
outpt.v.patchCoord = ivec4(0);
OSD_PATCH_CULL_COMPUTE_CLIPFLAGS(position);
OSD_USER_VARYING_PER_VERTEX();
}
#endif
//----------------------------------------------------------
// Patches.TessControlGregoryBasis
//----------------------------------------------------------
#ifdef OSD_PATCH_TESS_CONTROL_GREGORY_BASIS_SHADER
layout(vertices = 20) out;
in block {
ControlVertex v;
OSD_USER_VARYING_DECLARE
} inpt[];
out block {
ControlVertex v;
OSD_USER_VARYING_DECLARE
} outpt[];
#define ID gl_InvocationID
void main()
{
outpt[ID].v = inpt[ID].v;
OSD_USER_VARYING_PER_CONTROL_POINT(ID, ID);
ivec3 patchParam = OsdGetPatchParam(OsdGetPatchIndex(gl_PrimitiveID));
outpt[ID].v.patchCoord = OsdGetPatchCoord(patchParam);
if (ID == 0) {
OSD_PATCH_CULL(20);
vec4 tessLevelOuter = vec4(0);
vec2 tessLevelInner = vec2(0);
OsdGetTessLevels(inpt[0].v.position.xyz, inpt[15].v.position.xyz,
inpt[10].v.position.xyz, inpt[5].v.position.xyz,
patchParam, tessLevelOuter, tessLevelInner);
gl_TessLevelOuter[0] = tessLevelOuter[0];
gl_TessLevelOuter[1] = tessLevelOuter[1];
gl_TessLevelOuter[2] = tessLevelOuter[2];
gl_TessLevelOuter[3] = tessLevelOuter[3];
gl_TessLevelInner[0] = tessLevelInner[0];
gl_TessLevelInner[1] = tessLevelInner[1];
}
}
#endif
//----------------------------------------------------------
// Patches.TessEvalGregory
//----------------------------------------------------------
#ifdef OSD_PATCH_TESS_EVAL_GREGORY_BASIS_SHADER
layout(quads) in;
#if defined OSD_FRACTIONAL_ODD_SPACING
layout(fractional_odd_spacing) in;
#elif defined OSD_FRACTIONAL_EVEN_SPACING
layout(fractional_even_spacing) in;
#endif
in block {
ControlVertex v;
OSD_USER_VARYING_DECLARE
} inpt[];
out block {
OutputVertex v;
OSD_USER_VARYING_DECLARE
} outpt;
void main()
{
vec2 UV = gl_TessCoord.xy;
vec3 p[20];
for (int i = 0; i < 20; ++i) {
p[i] = inpt[i].v.position.xyz;
}
vec3 q[16];
float u = UV.x, v=UV.y;
float U = 1-u, V=1-v;
float d11 = u+v; if(u+v==0.0f) d11 = 1.0f;
float d12 = U+v; if(U+v==0.0f) d12 = 1.0f;
float d21 = u+V; if(u+V==0.0f) d21 = 1.0f;
float d22 = U+V; if(U+V==0.0f) d22 = 1.0f;
q[ 5] = (u*p[3] + v*p[4])/d11;
q[ 6] = (U*p[9] + v*p[8])/d12;
q[ 9] = (u*p[19] + V*p[18])/d21;
q[10] = (U*p[13] + V*p[14])/d22;
q[ 0] = p[0];
q[ 1] = p[1];
q[ 2] = p[7];
q[ 3] = p[5];
q[ 4] = p[2];
q[ 7] = p[6];
q[ 8] = p[16];
q[11] = p[12];
q[12] = p[15];
q[13] = p[17];
q[14] = p[11];
q[15] = p[10];
vec3 position = vec3(0, 0, 0);
vec3 uTangent = vec3(0, 0, 0);
vec3 vTangent = vec3(0, 0, 0);
#ifdef OSD_COMPUTE_NORMAL_DERIVATIVES
float B[4], D[4], C[4];
vec3 BUCP[4] = vec3[4](vec3(0,0,0), vec3(0,0,0), vec3(0,0,0), vec3(0,0,0)),
DUCP[4] = vec3[4](vec3(0,0,0), vec3(0,0,0), vec3(0,0,0), vec3(0,0,0)),
CUCP[4] = vec3[4](vec3(0,0,0), vec3(0,0,0), vec3(0,0,0), vec3(0,0,0));
vec3 dUU = vec3(0);
vec3 dVV = vec3(0);
vec3 dUV = vec3(0);
Univar4x4(UV.x, B, D, C);
for (int i=0; i<4; ++i) {
for (uint j=0; j<4; ++j) {
vec3 A = q[4*i + j];
BUCP[i] += A * B[j];
DUCP[i] += A * D[j];
CUCP[i] += A * C[j];
}
}
Univar4x4(UV.y, B, D, C);
for (int i=0; i<4; ++i) {
position += B[i] * BUCP[i];
uTangent += B[i] * DUCP[i];
vTangent += D[i] * BUCP[i];
dUU += B[i] * CUCP[i];
dVV += C[i] * BUCP[i];
dUV += D[i] * DUCP[i];
}
int level = inpt[0].v.patchCoord.z;
uTangent *= 3 * level;
vTangent *= 3 * level;
dUU *= 6 * level;
dVV *= 6 * level;
dUV *= 9 * level;
vec3 n = cross(uTangent, vTangent);
vec3 normal = normalize(n);
float E = dot(uTangent, uTangent);
float F = dot(uTangent, vTangent);
float G = dot(vTangent, vTangent);
float e = dot(normal, dUU);
float f = dot(normal, dUV);
float g = dot(normal, dVV);
vec3 Nu = (f*F-e*G)/(E*G-F*F) * uTangent + (e*F-f*E)/(E*G-F*F) * vTangent;
vec3 Nv = (g*F-f*G)/(E*G-F*F) * uTangent + (f*F-g*E)/(E*G-F*F) * vTangent;
Nu = Nu/length(n) - n * (dot(Nu,n)/pow(dot(n,n), 1.5));
Nv = Nv/length(n) - n * (dot(Nv,n)/pow(dot(n,n), 1.5));
outpt.v.Nu = Nu;
outpt.v.Nv = Nv;
#else
float B[4], D[4];
vec3 BUCP[4] = vec3[4](vec3(0,0,0), vec3(0,0,0), vec3(0,0,0), vec3(0,0,0)),
DUCP[4] = vec3[4](vec3(0,0,0), vec3(0,0,0), vec3(0,0,0), vec3(0,0,0));
Univar4x4(UV.x, B, D);
for (int i=0; i<4; ++i) {
for (uint j=0; j<4; ++j) {
vec3 A = q[4*i + j];
BUCP[i] += A * B[j];
DUCP[i] += A * D[j];
}
}
Univar4x4(UV.y, B, D);
for (int i=0; i<4; ++i) {
position += B[i] * BUCP[i];
uTangent += B[i] * DUCP[i];
vTangent += D[i] * BUCP[i];
}
int level = inpt[0].v.patchCoord.z;
uTangent *= 3 * level;
vTangent *= 3 * level;
vec3 normal = normalize(cross(uTangent, vTangent));
#endif
outpt.v.position = OsdModelViewMatrix() * vec4(position, 1.0f);
outpt.v.normal = (OsdModelViewMatrix() * vec4(normal, 0.0f)).xyz;
outpt.v.tangent = (OsdModelViewMatrix() * vec4(uTangent, 0.0f)).xyz;
outpt.v.bitangent = (OsdModelViewMatrix() * vec4(vTangent, 0.0f)).xyz;
OSD_USER_VARYING_PER_EVAL_POINT(UV, 0, 5, 15, 10);
outpt.v.tessCoord = UV;
outpt.v.patchCoord = OsdInterpolatePatchCoord(UV, inpt[0].v.patchCoord);
OSD_DISPLACEMENT_CALLBACK;
gl_Position = OsdProjectionMatrix() * outpt.v.position;
}
#endif