OpenSubdiv/opensubdiv/osd/hlslPatchBSpline.hlsl
David G Yu 8b4ef28116 Updated handling of patchParam and patchCoord
Each patch has a corresponding patchParam. This is a set of three values
specifying additional information about the patch:

   faceId    -- topological face identifier (e.g. Ptex FaceId)
   bitfield  -- refinement-level, non-quad, boundary, transition, uv-offset
   sharpness -- crease sharpness for a single-crease patch

These are stored in OsdPatchParamBuffer indexed by the value returned
from OsdGetPatchIndex() which is a function of the current PrimitiveID
along with an optional client provided offset.

Accessors are provided to extract values from a patchParam. These are
all named OsdGetPatch*().

While drawing patches, the patchParam is condensed into a patchCoord which
has four values (u, v, faceLevel, faceId). These patchCoords are treated
as int values during per-prim processing but are converted to float values
during per-vertex processing where the values are interpolated.

Also, cleaned up more of the shader namespace by giving an Osd prefix
to public functions, and consolidated boundary and transition handling
code into the PatchCommon shader files. The functions determining
tessellation levels are now all named OsdGetTessLevel*().
2015-05-06 13:47:33 -07:00

363 lines
11 KiB
HLSL

//
// Copyright 2013 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.
//
#if defined OSD_FRACTIONAL_ODD_SPACING
#define HS_PARTITION "fractional_odd"
#elif defined OSD_FRACTIONAL_EVEN_SPACING
#define HS_PARTITION "fractional_even"
#else
#define HS_PARTITION "integer"
#endif
//----------------------------------------------------------
// Patches.Vertex
//----------------------------------------------------------
void vs_main_patches( in InputVertex input,
out HullVertex output )
{
output.position = mul(OsdModelViewMatrix(), input.position);
OSD_PATCH_CULL_COMPUTE_CLIPFLAGS(input.position);
}
//----------------------------------------------------------
// Patches.HullBSpline
//----------------------------------------------------------
// Regular
static float4x4 Q = {
1.f/6.f, 4.f/6.f, 1.f/6.f, 0.f,
0.f, 4.f/6.f, 2.f/6.f, 0.f,
0.f, 2.f/6.f, 4.f/6.f, 0.f,
0.f, 1.f/6.f, 4.f/6.f, 1.f/6.f
};
// Infinite sharp
static float4x4 Mi = {
1.f/6.f, 4.f/6.f, 1.f/6.f, 0.f,
0.f, 4.f/6.f, 2.f/6.f, 0.f,
0.f, 2.f/6.f, 4.f/6.f, 0.f,
0.f, 0.f, 1.f, 0.f
};
// compute single-crease patch matrix
float4x4
ComputeMatrixSimplified(float sharpness)
{
float s = pow(2.0f, sharpness);
float s2 = s*s;
float s3 = s2*s;
float4x4 m ={
0, s + 1 + 3*s2 - s3, 7*s - 2 - 6*s2 + 2*s3, (1-s)*(s-1)*(s-1),
0, (1+s)*(1+s), 6*s - 2 - 2*s2, (s-1)*(s-1),
0, 1+s, 6*s - 2, 1-s,
0, 1, 6*s - 2, 1 };
m /= (s*6.0);
m[0][0] = 1.0/6.0;
return m;
}
HS_CONSTANT_FUNC_OUT
HSConstFunc(
InputPatch<HullVertex, OSD_PATCH_INPUT_SIZE> patch,
OutputPatch<HullVertex, 16> bezierPatch,
uint primitiveID : SV_PrimitiveID)
{
HS_CONSTANT_FUNC_OUT output;
float3 position[16];
for (int p=0; p<16; ++p) {
position[p] = bezierPatch[p].position.xyz;
}
int3 patchParam = OsdGetPatchParam(OsdGetPatchIndex(primitiveID));
OsdComputeBSplineBoundaryPoints(position, patchParam);
OSD_PATCH_CULL(OSD_PATCH_INPUT_SIZE);
float4 tessLevelOuter = float4(0,0,0,0);
float4 tessLevelInner = float4(0,0,0,0);
float4 tessOuterLo = float4(0,0,0,0);
float4 tessOuterHi = float4(0,0,0,0);
OsdGetTessLevels(position, patchParam,
tessLevelOuter, tessLevelInner,
tessOuterLo, tessOuterHi);
output.tessLevelOuter[0] = tessLevelOuter[0];
output.tessLevelOuter[1] = tessLevelOuter[1];
output.tessLevelOuter[2] = tessLevelOuter[2];
output.tessLevelOuter[3] = tessLevelOuter[3];
output.tessLevelInner[0] = tessLevelInner[0];
output.tessLevelInner[1] = tessLevelInner[1];
output.tessOuterLo = tessOuterLo;
output.tessOuterHi = tessOuterHi;
return output;
}
[domain("quad")]
[partitioning(HS_PARTITION)]
[outputtopology("triangle_cw")]
[outputcontrolpoints(16)]
[patchconstantfunc("HSConstFunc")]
HullVertex hs_main_patches(
in InputPatch<HullVertex, OSD_PATCH_INPUT_SIZE> patch,
uint primitiveID : SV_PrimitiveID,
in uint ID : SV_OutputControlPointID )
{
int i = ID%4;
int j = ID/4;
float3 position[16];
for (int p=0; p<16; ++p) {
position[p] = patch[p].position.xyz;
}
int3 patchParam = OsdGetPatchParam(OsdGetPatchIndex(primitiveID));
OsdComputeBSplineBoundaryPoints(position, patchParam);
float3 H[4];
for (int l=0; l<4; ++l) {
H[l] = float3(0,0,0);
for(int k=0; k<4; ++k) {
H[l] += Q[i][k] * position[l*4 + k];
}
}
HullVertex output;
#if defined OSD_PATCH_ENABLE_SINGLE_CREASE
float sharpness = OsdGetPatchSharpness(patchParam);
if (sharpness > 0) {
float Sf = floor(sharpness);
float Sc = ceil(sharpness);
float Sr = frac(sharpness);
float4x4 Mf = ComputeMatrixSimplified(Sf);
float4x4 Mc = ComputeMatrixSimplified(Sc);
float4x4 Mj = (1-Sr) * Mf + Sr * Mi;
float4x4 Ms = (1-Sr) * Mf + Sr * Mc;
float3 pos = float3(0,0,0);
float3 P1 = float3(0,0,0);
float3 P2 = float3(0,0,0);
for (int k=0; k<4; ++k) {
pos += Mi[j][k]*H[k]; // 0 to 1-2^(-Sf)
P1 += Mj[j][k]*H[k]; // 1-2^(-Sf) to 1-2^(-Sc)
P2 += Ms[j][k]*H[k]; // 1-2^(-Sc) to 1
}
output.position = float4(pos, 1.0);
output.P1 = float4(P1, 1.0);
output.P2 = float4(P2, 1.0);
output.sharpness = sharpness;
} else {
float3 pos = float3(0,0,0);
for (int k=0; k<4; ++k){
pos += Q[j][k]*H[k];
}
output.position = float4(pos, 1.0);
output.sharpness = 0;
}
#else
float3 pos = float3(0,0,0);
for (int k=0; k<4; ++k){
pos += Q[j][k]*H[k];
}
output.position = float4(pos, 1.0);
#endif
output.patchCoord = OsdGetPatchCoord(patchParam);
return output;
}
//----------------------------------------------------------
// Patches.DomainBSpline
//----------------------------------------------------------
[domain("quad")]
void ds_main_patches(
in HS_CONSTANT_FUNC_OUT input,
in OutputPatch<HullVertex, 16> patch,
in float2 domainCoord : SV_DomainLocation,
out OutputVertex output )
{
float2 UV = OsdGetTessParameterization(domainCoord,
input.tessOuterLo,
input.tessOuterHi);
#ifdef OSD_COMPUTE_NORMAL_DERIVATIVES
float B[4], D[4], C[4];
float3 BUCP[4] = {float3(0,0,0), float3(0,0,0), float3(0,0,0), float3(0,0,0)},
DUCP[4] = {float3(0,0,0), float3(0,0,0), float3(0,0,0), float3(0,0,0)},
CUCP[4] = {float3(0,0,0), float3(0,0,0), float3(0,0,0), float3(0,0,0)};
Univar4x4(UV.x, B, D, C);
#else
float B[4], D[4];
float3 BUCP[4] = {float3(0,0,0), float3(0,0,0), float3(0,0,0), float3(0,0,0)},
DUCP[4] = {float3(0,0,0), float3(0,0,0), float3(0,0,0), float3(0,0,0)};
Univar4x4(UV.x, B, D);
#endif
// ----------------------------------------------------------------
#if defined OSD_PATCH_ENABLE_SINGLE_CREASE
// sharpness
float sharpness = patch[0].sharpness;
if (sharpness != 0) {
float s0 = 1.0 - pow(2.0f, -floor(sharpness));
float s1 = 1.0 - pow(2.0f, -ceil(sharpness));
for (int i=0; i<4; ++i) {
for (int j=0; j<4; ++j) {
int k = 4*i + j;
float s = UV.y;
float3 A = (s < s0) ?
patch[k].position.xyz :
((s < s1) ?
patch[k].P1.xyz :
patch[k].P2.xyz);
BUCP[i] += A * B[j];
DUCP[i] += A * D[j];
#ifdef OSD_COMPUTE_NORMAL_DERIVATIVES
CUCP[i] += A * C[j];
#endif
}
}
output.sharpness = sharpness;
} else {
for (int i=0; i<4; ++i) {
for (int j=0; j<4; ++j) {
float3 A = patch[4*i + j].position.xyz;
BUCP[i] += A * B[j];
DUCP[i] += A * D[j];
#ifdef OSD_COMPUTE_NORMAL_DERIVATIVES
CUCP[i] += A * C[j];
#endif
}
}
output.sharpness = 0;
}
#else
// ----------------------------------------------------------------
for (int i=0; i<4; ++i) {
for (int j=0; j<4; ++j) {
float3 A = patch[4*i + j].position.xyz;
BUCP[i] += A * B[j];
DUCP[i] += A * D[j];
#ifdef OSD_COMPUTE_NORMAL_DERIVATIVES
CUCP[i] += A * C[j];
#endif
}
}
#endif
// ----------------------------------------------------------------
float3 WorldPos = float3(0,0,0);
float3 Tangent = float3(0,0,0);
float3 BiTangent = float3(0,0,0);
#ifdef OSD_COMPUTE_NORMAL_DERIVATIVES
// used for weingarten term
Univar4x4(UV.y, B, D, C);
float3 dUU = float3(0,0,0);
float3 dVV = float3(0,0,0);
float3 dUV = float3(0,0,0);
for (int k=0; k<4; ++k) {
WorldPos += B[k] * BUCP[k];
Tangent += B[k] * DUCP[k];
BiTangent += D[k] * BUCP[k];
dUU += B[k] * CUCP[k];
dVV += C[k] * BUCP[k];
dUV += D[k] * DUCP[k];
}
int level = patch[0].patchCoord.z;
Tangent *= 3 * level;
BiTangent *= 3 * level;
dUU *= 6 * level;
dVV *= 6 * level;
dUV *= 9 * level;
float3 n = cross(Tangent, BiTangent);
float3 normal = normalize(n);
float E = dot(Tangent, Tangent);
float F = dot(Tangent, BiTangent);
float G = dot(BiTangent, BiTangent);
float e = dot(normal, dUU);
float f = dot(normal, dUV);
float g = dot(normal, dVV);
float3 Nu = (f*F-e*G)/(E*G-F*F) * Tangent + (e*F-f*E)/(E*G-F*F) * BiTangent;
float3 Nv = (g*F-f*G)/(E*G-F*F) * Tangent + (f*F-g*E)/(E*G-F*F) * BiTangent;
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));
output.tangent = Tangent;
output.bitangent = BiTangent;
output.Nu = Nu;
output.Nv = Nv;
#else
Univar4x4(UV.y, B, D);
for (int k=0; k<4; ++k) {
WorldPos += B[k] * BUCP[k];
Tangent += B[k] * DUCP[k];
BiTangent += D[k] * BUCP[k];
}
int level = patch[0].patchCoord.z;
Tangent *= 3 * level;
BiTangent *= 3 * level;
float3 normal = normalize(cross(Tangent, BiTangent));
output.tangent = Tangent;
output.bitangent = BiTangent;
#endif
output.position = float4(WorldPos, 1.0f);
output.normal = normal;
output.patchCoord = OsdInterpolatePatchCoord(UV, patch[0].patchCoord);
OSD_DISPLACEMENT_CALLBACK;
output.positionOut = mul(OsdProjectionMatrix(),
float4(output.position.xyz, 1.0f));
output.edgeDistance = 0;
}