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Moved HLSL tess factor code to separate file

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Moved shader code which computes tessellation factors and
tessellation parameterization into a separate source file.
This commit is contained in:
David G Yu 2019-04-24 17:51:39 -07:00
parent fda4ded404
commit aa0def2b95
4 changed files with 554 additions and 526 deletions
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1
opensubdiv/osd/CMakeLists.txt
View File

@ -213,6 +213,7 @@ if( DXSDK_FOUND )
list(APPEND KERNEL_FILES
hlslComputeKernel.hlsl
hlslPatchCommon.hlsl
hlslPatchCommonTess.hlsl
hlslPatchBSpline.hlsl
hlslPatchGregory.hlsl
hlslPatchGregoryBasis.hlsl

526
opensubdiv/osd/hlslPatchCommon.hlsl
View File

@ -26,20 +26,6 @@
// Patches.Common
//----------------------------------------------------------
// For now, fractional spacing is supported only with screen space tessellation
#ifndef OSD_ENABLE_SCREENSPACE_TESSELLATION
#undef OSD_FRACTIONAL_EVEN_SPACING
#undef OSD_FRACTIONAL_ODD_SPACING
#endif
#if defined OSD_FRACTIONAL_EVEN_SPACING
#define OSD_PARTITIONING "fractional_even"
#elif defined OSD_FRACTIONAL_ODD_SPACING
#define OSD_PARTITIONING "fractional_odd"
#else
#define OSD_PARTITIONING "integer"
#endif
struct InputVertex {
float4 position : POSITION;
float3 normal : NORMAL;
@ -70,13 +56,6 @@ struct OutputVertex {
#endif
};
struct HS_CONSTANT_FUNC_OUT {
float tessLevelInner[2] : SV_InsideTessFactor;
float tessLevelOuter[4] : SV_TessFactor;
float4 tessOuterLo : TRANSITIONLO;
float4 tessOuterHi : TRANSITIONHI;
};
// osd shaders need following functions defined
float4x4 OsdModelViewMatrix();
float4x4 OsdProjectionMatrix();
@ -430,511 +409,6 @@ OsdComputeBSplineBoundaryPoints(inout float3 cpt[16], int3 patchParam)
}
}
// ----------------------------------------------------------------------------
// Tessellation
// ----------------------------------------------------------------------------
//
// Organization of B-spline and Bezier control points.
//
// Each patch is defined by 16 control points (labeled 0-15).
//
// The patch will be evaluated across the domain from (0,0) at
// the lower-left to (1,1) at the upper-right. When computing
// adaptive tessellation metrics, we consider refined vertex-vertex
// and edge-vertex points along the transition edges of the patch
// (labeled vv* and ev* respectively).
//
// The two segments of each transition edge are labeled Lo and Hi,
// with the Lo segment occurring before the Hi segment along the
// transition edge's domain parameterization. These Lo and Hi segment
// tessellation levels determine how domain evaluation coordinates
// are remapped along transition edges. The Hi segment value will
// be zero for a non-transition edge.
//
// (0,1) (1,1)
//
// vv3 ev23 vv2
// | Lo3 | Hi3 |
// --O-----------O-----+-----O-----------O--
// | 12 | 13 14 | 15 |
// | | | |
// | | | |
// Hi0 | | | | Hi2
// | | | |
// O-----------O-----------O-----------O
// | 8 | 9 10 | 11 |
// | | | |
// ev03 --+ | | +-- ev12
// | | | |
// | 4 | 5 6 | 7 |
// O-----------O-----------O-----------O
// | | | |
// Lo0 | | | | Lo2
// | | | |
// | | | |
// | 0 | 1 2 | 3 |
// --O-----------O-----+-----O-----------O--
// | Lo1 | Hi1 |
// vv0 ev01 vv1
//
// (0,0) (1,0)
//
#define OSD_MAX_TESS_LEVEL 64
float OsdComputePostProjectionSphereExtent(float3 center, float diameter)
{
float4 p = mul(OsdProjectionMatrix(), float4(center, 1.0));
return abs(diameter * OsdProjectionMatrix()[1][1] / p.w);
}
float OsdComputeTessLevel(float3 p0, float3 p1)
{
// Adaptive factor can be any computation that depends only on arg values.
// Project the diameter of the edge's bounding sphere instead of using the
// length of the projected edge itself to avoid problems near silhouettes.
p0 = mul(OsdModelViewMatrix(), float4(p0, 1.0)).xyz;
p1 = mul(OsdModelViewMatrix(), float4(p1, 1.0)).xyz;
float3 center = (p0 + p1) / 2.0;
float diameter = distance(p0, p1);
float projLength = OsdComputePostProjectionSphereExtent(center, diameter);
float tessLevel = max(1.0, OsdTessLevel() * projLength);
// We restrict adaptive tessellation levels to half of the device
// supported maximum because transition edges are split into two
// halves and the sum of the two corresponding levels must not exceed
// the device maximum. We impose this limit even for non-transition
// edges because a non-transition edge must be able to match up with
// one half of the transition edge of an adjacent transition patch.
return min(tessLevel, OSD_MAX_TESS_LEVEL / 2);
}
void
OsdGetTessLevelsUniform(int3 patchParam,
out float4 tessOuterLo, out float4 tessOuterHi)
{
// Uniform factors are simple powers of two for each level.
// The maximum here can be increased if we know the maximum
// refinement level of the mesh:
// min(OSD_MAX_TESS_LEVEL, pow(2, MaximumRefinementLevel-1)
int refinementLevel = OsdGetPatchRefinementLevel(patchParam);
float tessLevel = min(OsdTessLevel(), OSD_MAX_TESS_LEVEL) /
pow(2, refinementLevel-1);
// tessLevels of transition edge should be clamped to 2.
int transitionMask = OsdGetPatchTransitionMask(patchParam);
float4 tessLevelMin = float4(1,1,1,1)
+ float4(((transitionMask & 8) >> 3),
((transitionMask & 1) >> 0),
((transitionMask & 2) >> 1),
((transitionMask & 4) >> 2));
tessOuterLo = max(float4(tessLevel,tessLevel,tessLevel,tessLevel),
tessLevelMin);
tessOuterHi = float4(0,0,0,0);
}
void
OsdGetTessLevelsRefinedPoints(float3 cp[16], int3 patchParam,
out float4 tessOuterLo, out float4 tessOuterHi)
{
// Each edge of a transition patch is adjacent to one or two patches
// at the next refined level of subdivision. We compute the corresponding
// vertex-vertex and edge-vertex refined points along the edges of the
// patch using Catmull-Clark subdivision stencil weights.
// For simplicity, we let the optimizer discard unused computation.
float3 vv0 = (cp[0] + cp[2] + cp[8] + cp[10]) * 0.015625 +
(cp[1] + cp[4] + cp[6] + cp[9]) * 0.09375 + cp[5] * 0.5625;
float3 ev01 = (cp[1] + cp[2] + cp[9] + cp[10]) * 0.0625 +
(cp[5] + cp[6]) * 0.375;
float3 vv1 = (cp[1] + cp[3] + cp[9] + cp[11]) * 0.015625 +
(cp[2] + cp[5] + cp[7] + cp[10]) * 0.09375 + cp[6] * 0.5625;
float3 ev12 = (cp[5] + cp[7] + cp[9] + cp[11]) * 0.0625 +
(cp[6] + cp[10]) * 0.375;
float3 vv2 = (cp[5] + cp[7] + cp[13] + cp[15]) * 0.015625 +
(cp[6] + cp[9] + cp[11] + cp[14]) * 0.09375 + cp[10] * 0.5625;
float3 ev23 = (cp[5] + cp[6] + cp[13] + cp[14]) * 0.0625 +
(cp[9] + cp[10]) * 0.375;
float3 vv3 = (cp[4] + cp[6] + cp[12] + cp[14]) * 0.015625 +
(cp[5] + cp[8] + cp[10] + cp[13]) * 0.09375 + cp[9] * 0.5625;
float3 ev03 = (cp[4] + cp[6] + cp[8] + cp[10]) * 0.0625 +
(cp[5] + cp[9]) * 0.375;
tessOuterLo = float4(0,0,0,0);
tessOuterHi = float4(0,0,0,0);
int transitionMask = OsdGetPatchTransitionMask(patchParam);
if ((transitionMask & 8) != 0) {
tessOuterLo[0] = OsdComputeTessLevel(vv0, ev03);
tessOuterHi[0] = OsdComputeTessLevel(vv3, ev03);
} else {
tessOuterLo[0] = OsdComputeTessLevel(cp[5], cp[9]);
}
if ((transitionMask & 1) != 0) {
tessOuterLo[1] = OsdComputeTessLevel(vv0, ev01);
tessOuterHi[1] = OsdComputeTessLevel(vv1, ev01);
} else {
tessOuterLo[1] = OsdComputeTessLevel(cp[5], cp[6]);
}
if ((transitionMask & 2) != 0) {
tessOuterLo[2] = OsdComputeTessLevel(vv1, ev12);
tessOuterHi[2] = OsdComputeTessLevel(vv2, ev12);
} else {
tessOuterLo[2] = OsdComputeTessLevel(cp[6], cp[10]);
}
if ((transitionMask & 4) != 0) {
tessOuterLo[3] = OsdComputeTessLevel(vv3, ev23);
tessOuterHi[3] = OsdComputeTessLevel(vv2, ev23);
} else {
tessOuterLo[3] = OsdComputeTessLevel(cp[9], cp[10]);
}
}
void
OsdGetTessLevelsLimitPoints(OsdPerPatchVertexBezier cpBezier[16],
int3 patchParam, out float4 tessOuterLo, out float4 tessOuterHi)
{
// Each edge of a transition patch is adjacent to one or two patches
// at the next refined level of subdivision. When the patch control
// points have been converted to the Bezier basis, the control points
// at the four corners are on the limit surface (since a Bezier patch
// interpolates its corner control points). We can compute an adaptive
// tessellation level for transition edges on the limit surface by
// evaluating a limit position at the mid point of each transition edge.
tessOuterLo = float4(0,0,0,0);
tessOuterHi = float4(0,0,0,0);
int transitionMask = OsdGetPatchTransitionMask(patchParam);
#if defined OSD_PATCH_ENABLE_SINGLE_CREASE
// PERFOMANCE: we just need to pick the correct corner points from P, P1, P2
float3 p0 = OsdEvalBezier(cpBezier, patchParam, float2(0.0, 0.0));
float3 p3 = OsdEvalBezier(cpBezier, patchParam, float2(1.0, 0.0));
float3 p12 = OsdEvalBezier(cpBezier, patchParam, float2(0.0, 1.0));
float3 p15 = OsdEvalBezier(cpBezier, patchParam, float2(1.0, 1.0));
if ((transitionMask & 8) != 0) {
float3 ev03 = OsdEvalBezier(cpBezier, patchParam, float2(0.0, 0.5));
tessOuterLo[0] = OsdComputeTessLevel(p0, ev03);
tessOuterHi[0] = OsdComputeTessLevel(p12, ev03);
} else {
tessOuterLo[0] = OsdComputeTessLevel(p0, p12);
}
if ((transitionMask & 1) != 0) {
float3 ev01 = OsdEvalBezier(cpBezier, patchParam, float2(0.5, 0.0));
tessOuterLo[1] = OsdComputeTessLevel(p0, ev01);
tessOuterHi[1] = OsdComputeTessLevel(p3, ev01);
} else {
tessOuterLo[1] = OsdComputeTessLevel(p0, p3);
}
if ((transitionMask & 2) != 0) {
float3 ev12 = OsdEvalBezier(cpBezier, patchParam, float2(1.0, 0.5));
tessOuterLo[2] = OsdComputeTessLevel(p3, ev12);
tessOuterHi[2] = OsdComputeTessLevel(p15, ev12);
} else {
tessOuterLo[2] = OsdComputeTessLevel(p3, p15);
}
if ((transitionMask & 4) != 0) {
float3 ev23 = OsdEvalBezier(cpBezier, patchParam, float2(0.5, 1.0));
tessOuterLo[3] = OsdComputeTessLevel(p12, ev23);
tessOuterHi[3] = OsdComputeTessLevel(p15, ev23);
} else {
tessOuterLo[3] = OsdComputeTessLevel(p12, p15);
}
#else
if ((transitionMask & 8) != 0) {
float3 ev03 = OsdEvalBezier(cpBezier, patchParam, float2(0.0, 0.5));
tessOuterLo[0] = OsdComputeTessLevel(cpBezier[0].P, ev03);
tessOuterHi[0] = OsdComputeTessLevel(cpBezier[12].P, ev03);
} else {
tessOuterLo[0] = OsdComputeTessLevel(cpBezier[0].P, cpBezier[12].P);
}
if ((transitionMask & 1) != 0) {
float3 ev01 = OsdEvalBezier(cpBezier, patchParam, float2(0.5, 0.0));
tessOuterLo[1] = OsdComputeTessLevel(cpBezier[0].P, ev01);
tessOuterHi[1] = OsdComputeTessLevel(cpBezier[3].P, ev01);
} else {
tessOuterLo[1] = OsdComputeTessLevel(cpBezier[0].P, cpBezier[3].P);
}
if ((transitionMask & 2) != 0) {
float3 ev12 = OsdEvalBezier(cpBezier, patchParam, float2(1.0, 0.5));
tessOuterLo[2] = OsdComputeTessLevel(cpBezier[3].P, ev12);
tessOuterHi[2] = OsdComputeTessLevel(cpBezier[15].P, ev12);
} else {
tessOuterLo[2] = OsdComputeTessLevel(cpBezier[3].P, cpBezier[15].P);
}
if ((transitionMask & 4) != 0) {
float3 ev23 = OsdEvalBezier(cpBezier, patchParam, float2(0.5, 1.0));
tessOuterLo[3] = OsdComputeTessLevel(cpBezier[12].P, ev23);
tessOuterHi[3] = OsdComputeTessLevel(cpBezier[15].P, ev23);
} else {
tessOuterLo[3] = OsdComputeTessLevel(cpBezier[12].P, cpBezier[15].P);
}
#endif
}
// Round up to the nearest even integer
float OsdRoundUpEven(float x) {
return 2*ceil(x/2);
}
// Round up to the nearest odd integer
float OsdRoundUpOdd(float x) {
return 2*ceil((x+1)/2)-1;
}
// Compute outer and inner tessellation levels taking into account the
// current tessellation spacing mode.
void
OsdComputeTessLevels(inout float4 tessOuterLo, inout float4 tessOuterHi,
out float4 tessLevelOuter, out float2 tessLevelInner)
{
// Outer levels are the sum of the Lo and Hi segments where the Hi
// segments will have lengths of zero for non-transition edges.
#if defined OSD_FRACTIONAL_EVEN_SPACING
// Combine fractional outer transition edge levels before rounding.
float4 combinedOuter = tessOuterLo + tessOuterHi;
// Round the segments of transition edges separately. We will recover the
// fractional parameterization of transition edges after tessellation.
tessLevelOuter = combinedOuter;
if (tessOuterHi[0] > 0) {
tessLevelOuter[0] =
OsdRoundUpEven(tessOuterLo[0]) + OsdRoundUpEven(tessOuterHi[0]);
}
if (tessOuterHi[1] > 0) {
tessLevelOuter[1] =
OsdRoundUpEven(tessOuterLo[1]) + OsdRoundUpEven(tessOuterHi[1]);
}
if (tessOuterHi[2] > 0) {
tessLevelOuter[2] =
OsdRoundUpEven(tessOuterLo[2]) + OsdRoundUpEven(tessOuterHi[2]);
}
if (tessOuterHi[3] > 0) {
tessLevelOuter[3] =
OsdRoundUpEven(tessOuterLo[3]) + OsdRoundUpEven(tessOuterHi[3]);
}
#elif defined OSD_FRACTIONAL_ODD_SPACING
// Combine fractional outer transition edge levels before rounding.
float4 combinedOuter = tessOuterLo + tessOuterHi;
// Round the segments of transition edges separately. We will recover the
// fractional parameterization of transition edges after tessellation.
//
// The sum of the two outer odd segment lengths will be an even number
// which the tessellator will increase by +1 so that there will be a
// total odd number of segments. We clamp the combinedOuter tess levels
// (used to compute the inner tess levels) so that the outer transition
// edges will be sampled without degenerate triangles.
tessLevelOuter = combinedOuter;
if (tessOuterHi[0] > 0) {
tessLevelOuter[0] =
OsdRoundUpOdd(tessOuterLo[0]) + OsdRoundUpOdd(tessOuterHi[0]);
combinedOuter = max(float4(3,3,3,3), combinedOuter);
}
if (tessOuterHi[1] > 0) {
tessLevelOuter[1] =
OsdRoundUpOdd(tessOuterLo[1]) + OsdRoundUpOdd(tessOuterHi[1]);
combinedOuter = max(float4(3,3,3,3), combinedOuter);
}
if (tessOuterHi[2] > 0) {
tessLevelOuter[2] =
OsdRoundUpOdd(tessOuterLo[2]) + OsdRoundUpOdd(tessOuterHi[2]);
combinedOuter = max(float4(3,3,3,3), combinedOuter);
}
if (tessOuterHi[3] > 0) {
tessLevelOuter[3] =
OsdRoundUpOdd(tessOuterLo[3]) + OsdRoundUpOdd(tessOuterHi[3]);
combinedOuter = max(float4(3,3,3,3), combinedOuter);
}
#else
// Round equally spaced transition edge levels before combining.
tessOuterLo = round(tessOuterLo);
tessOuterHi = round(tessOuterHi);
float4 combinedOuter = tessOuterLo + tessOuterHi;
tessLevelOuter = combinedOuter;
#endif
// Inner levels are the averages the corresponding outer levels.
tessLevelInner[0] = (combinedOuter[1] + combinedOuter[3]) * 0.5;
tessLevelInner[1] = (combinedOuter[0] + combinedOuter[2]) * 0.5;
}
void
OsdGetTessLevelsUniform(int3 patchParam,
out float4 tessLevelOuter, out float2 tessLevelInner,
out float4 tessOuterLo, out float4 tessOuterHi)
{
OsdGetTessLevelsUniform(patchParam, tessOuterLo, tessOuterHi);
OsdComputeTessLevels(tessOuterLo, tessOuterHi,
tessLevelOuter, tessLevelInner);
}
void
OsdGetTessLevelsAdaptiveRefinedPoints(float3 cpRefined[16], int3 patchParam,
out float4 tessLevelOuter, out float2 tessLevelInner,
out float4 tessOuterLo, out float4 tessOuterHi)
{
OsdGetTessLevelsRefinedPoints(cpRefined, patchParam,
tessOuterLo, tessOuterHi);
OsdComputeTessLevels(tessOuterLo, tessOuterHi,
tessLevelOuter, tessLevelInner);
}
void
OsdGetTessLevelsAdaptiveLimitPoints(OsdPerPatchVertexBezier cpBezier[16],
int3 patchParam,
out float4 tessLevelOuter, out float2 tessLevelInner,
out float4 tessOuterLo, out float4 tessOuterHi)
{
OsdGetTessLevelsLimitPoints(cpBezier, patchParam,
tessOuterLo, tessOuterHi);
OsdComputeTessLevels(tessOuterLo, tessOuterHi,
tessLevelOuter, tessLevelInner);
}
void
OsdGetTessLevels(float3 cp0, float3 cp1, float3 cp2, float3 cp3,
int3 patchParam,
out float4 tessLevelOuter, out float2 tessLevelInner)
{
float4 tessOuterLo = float4(0,0,0,0);
float4 tessOuterHi = float4(0,0,0,0);
#if defined OSD_ENABLE_SCREENSPACE_TESSELLATION
tessOuterLo[0] = OsdComputeTessLevel(cp0, cp1);
tessOuterLo[1] = OsdComputeTessLevel(cp0, cp3);
tessOuterLo[2] = OsdComputeTessLevel(cp2, cp3);
tessOuterLo[3] = OsdComputeTessLevel(cp1, cp2);
tessOuterHi = float4(0,0,0,0);
#else
OsdGetTessLevelsUniform(patchParam, tessOuterLo, tessOuterHi);
#endif
OsdComputeTessLevels(tessOuterLo, tessOuterHi,
tessLevelOuter, tessLevelInner);
}
#if defined OSD_FRACTIONAL_EVEN_SPACING || defined OSD_FRACTIONAL_ODD_SPACING
float
OsdGetTessFractionalSplit(float t, float level, float levelUp)
{
// Fractional tessellation of an edge will produce n segments where n
// is the tessellation level of the edge (level) rounded up to the
// nearest even or odd integer (levelUp). There will be n-2 segments of
// equal length (dx1) and two additional segments of equal length (dx0)
// that are typically shorter than the other segments. The two additional
// segments should be placed symmetrically on opposite sides of the
// edge (offset).
#if defined OSD_FRACTIONAL_EVEN_SPACING
if (level <= 2) return t;
float base = pow(2.0,floor(log2(levelUp)));
float offset = 1.0/(int(2*base-levelUp)/2 & int(base/2-1));
#elif defined OSD_FRACTIONAL_ODD_SPACING
if (level <= 1) return t;
float base = pow(2.0,floor(log2(levelUp)));
float offset = 1.0/(((int(2*base-levelUp)/2+1) & int(base/2-1))+1);
#endif
float dx0 = (1.0 - (levelUp-level)/2) / levelUp;
float dx1 = (1.0 - 2.0*dx0) / (levelUp - 2.0*ceil(dx0));
if (t < 0.5) {
float x = levelUp/2 - round(t*levelUp);
return 0.5 - (x*dx1 + int(x*offset > 1) * (dx0 - dx1));
} else if (t > 0.5) {
float x = round(t*levelUp) - levelUp/2;
return 0.5 + (x*dx1 + int(x*offset > 1) * (dx0 - dx1));
} else {
return t;
}
}
#endif
float
OsdGetTessTransitionSplit(float t, float lo, float hi)
{
#if defined OSD_FRACTIONAL_EVEN_SPACING
float loRoundUp = OsdRoundUpEven(lo);
float hiRoundUp = OsdRoundUpEven(hi);
// Convert the parametric t into a segment index along the combined edge.
float ti = round(t * (loRoundUp + hiRoundUp));
if (ti <= loRoundUp) {
float t0 = ti / loRoundUp;
return OsdGetTessFractionalSplit(t0, lo, loRoundUp) * 0.5;
} else {
float t1 = (ti - loRoundUp) / hiRoundUp;
return OsdGetTessFractionalSplit(t1, hi, hiRoundUp) * 0.5 + 0.5;
}
#elif defined OSD_FRACTIONAL_ODD_SPACING
float loRoundUp = OsdRoundUpOdd(lo);
float hiRoundUp = OsdRoundUpOdd(hi);
// Convert the parametric t into a segment index along the combined edge.
// The +1 below is to account for the extra segment produced by the
// tessellator since the sum of two odd tess levels will be rounded
// up by one to the next odd integer tess level.
float ti = round(t * (loRoundUp + hiRoundUp + 1));
if (ti <= loRoundUp) {
float t0 = ti / loRoundUp;
return OsdGetTessFractionalSplit(t0, lo, loRoundUp) * 0.5;
} else if (ti > (loRoundUp+1)) {
float t1 = (ti - (loRoundUp+1)) / hiRoundUp;
return OsdGetTessFractionalSplit(t1, hi, hiRoundUp) * 0.5 + 0.5;
} else {
return 0.5;
}
#else
// Convert the parametric t into a segment index along the combined edge.
float ti = round(t * (lo + hi));
if (ti <= lo) {
return (ti / lo) * 0.5;
} else {
return ((ti - lo) / hi) * 0.5 + 0.5;
}
#endif
}
float2
OsdGetTessParameterization(float2 uv, float4 tessOuterLo, float4 tessOuterHi)
{
float2 UV = uv;
if (UV.x == 0 && tessOuterHi[0] > 0) {
UV.y = OsdGetTessTransitionSplit(UV.y, tessOuterLo[0], tessOuterHi[0]);
} else
if (UV.y == 0 && tessOuterHi[1] > 0) {
UV.x = OsdGetTessTransitionSplit(UV.x, tessOuterLo[1], tessOuterHi[1]);
} else
if (UV.x == 1 && tessOuterHi[2] > 0) {
UV.y = OsdGetTessTransitionSplit(UV.y, tessOuterLo[2], tessOuterHi[2]);
} else
if (UV.y == 1 && tessOuterHi[3] > 0) {
UV.x = OsdGetTessTransitionSplit(UV.x, tessOuterLo[3], tessOuterHi[3]);
}
return UV;
}
// ----------------------------------------------------------------------------
// BSpline
// ----------------------------------------------------------------------------

549
opensubdiv/osd/hlslPatchCommonTess.hlsl Normal file
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@ -0,0 +1,549 @@
//
// Copyright 2013-2019 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.
//
// ----------------------------------------------------------------------------
// Tessellation
// ----------------------------------------------------------------------------
// For now, fractional spacing is supported only with screen space tessellation
#ifndef OSD_ENABLE_SCREENSPACE_TESSELLATION
#undef OSD_FRACTIONAL_EVEN_SPACING
#undef OSD_FRACTIONAL_ODD_SPACING
#endif
#if defined OSD_FRACTIONAL_EVEN_SPACING
#define OSD_PARTITIONING "fractional_even"
#elif defined OSD_FRACTIONAL_ODD_SPACING
#define OSD_PARTITIONING "fractional_odd"
#else
#define OSD_PARTITIONING "integer"
#endif
struct HS_CONSTANT_FUNC_OUT {
float tessLevelInner[2] : SV_InsideTessFactor;
float tessLevelOuter[4] : SV_TessFactor;
float4 tessOuterLo : TRANSITIONLO;
float4 tessOuterHi : TRANSITIONHI;
};
//
// Organization of B-spline and Bezier control points.
//
// Each patch is defined by 16 control points (labeled 0-15).
//
// The patch will be evaluated across the domain from (0,0) at
// the lower-left to (1,1) at the upper-right. When computing
// adaptive tessellation metrics, we consider refined vertex-vertex
// and edge-vertex points along the transition edges of the patch
// (labeled vv* and ev* respectively).
//
// The two segments of each transition edge are labeled Lo and Hi,
// with the Lo segment occurring before the Hi segment along the
// transition edge's domain parameterization. These Lo and Hi segment
// tessellation levels determine how domain evaluation coordinates
// are remapped along transition edges. The Hi segment value will
// be zero for a non-transition edge.
//
// (0,1) (1,1)
//
// vv3 ev23 vv2
// | Lo3 | Hi3 |
// --O-----------O-----+-----O-----------O--
// | 12 | 13 14 | 15 |
// | | | |
// | | | |
// Hi0 | | | | Hi2
// | | | |
// O-----------O-----------O-----------O
// | 8 | 9 10 | 11 |
// | | | |
// ev03 --+ | | +-- ev12
// | | | |
// | 4 | 5 6 | 7 |
// O-----------O-----------O-----------O
// | | | |
// Lo0 | | | | Lo2
// | | | |
// | | | |
// | 0 | 1 2 | 3 |
// --O-----------O-----+-----O-----------O--
// | Lo1 | Hi1 |
// vv0 ev01 vv1
//
// (0,0) (1,0)
//
#define OSD_MAX_TESS_LEVEL 64
float OsdComputePostProjectionSphereExtent(float3 center, float diameter)
{
float4 p = mul(OsdProjectionMatrix(), float4(center, 1.0));
return abs(diameter * OsdProjectionMatrix()[1][1] / p.w);
}
float OsdComputeTessLevel(float3 p0, float3 p1)
{
// Adaptive factor can be any computation that depends only on arg values.
// Project the diameter of the edge's bounding sphere instead of using the
// length of the projected edge itself to avoid problems near silhouettes.
p0 = mul(OsdModelViewMatrix(), float4(p0, 1.0)).xyz;
p1 = mul(OsdModelViewMatrix(), float4(p1, 1.0)).xyz;
float3 center = (p0 + p1) / 2.0;
float diameter = distance(p0, p1);
float projLength = OsdComputePostProjectionSphereExtent(center, diameter);
float tessLevel = max(1.0, OsdTessLevel() * projLength);
// We restrict adaptive tessellation levels to half of the device
// supported maximum because transition edges are split into two
// halves and the sum of the two corresponding levels must not exceed
// the device maximum. We impose this limit even for non-transition
// edges because a non-transition edge must be able to match up with
// one half of the transition edge of an adjacent transition patch.
return min(tessLevel, OSD_MAX_TESS_LEVEL / 2);
}
void
OsdGetTessLevelsUniform(int3 patchParam,
out float4 tessOuterLo, out float4 tessOuterHi)
{
// Uniform factors are simple powers of two for each level.
// The maximum here can be increased if we know the maximum
// refinement level of the mesh:
// min(OSD_MAX_TESS_LEVEL, pow(2, MaximumRefinementLevel-1)
int refinementLevel = OsdGetPatchRefinementLevel(patchParam);
float tessLevel = min(OsdTessLevel(), OSD_MAX_TESS_LEVEL) /
pow(2, refinementLevel-1);
// tessLevels of transition edge should be clamped to 2.
int transitionMask = OsdGetPatchTransitionMask(patchParam);
float4 tessLevelMin = float4(1,1,1,1)
+ float4(((transitionMask & 8) >> 3),
((transitionMask & 1) >> 0),
((transitionMask & 2) >> 1),
((transitionMask & 4) >> 2));
tessOuterLo = max(float4(tessLevel,tessLevel,tessLevel,tessLevel),
tessLevelMin);
tessOuterHi = float4(0,0,0,0);
}
void
OsdGetTessLevelsRefinedPoints(float3 cp[16], int3 patchParam,
out float4 tessOuterLo, out float4 tessOuterHi)
{
// Each edge of a transition patch is adjacent to one or two patches
// at the next refined level of subdivision. We compute the corresponding
// vertex-vertex and edge-vertex refined points along the edges of the
// patch using Catmull-Clark subdivision stencil weights.
// For simplicity, we let the optimizer discard unused computation.
float3 vv0 = (cp[0] + cp[2] + cp[8] + cp[10]) * 0.015625 +
(cp[1] + cp[4] + cp[6] + cp[9]) * 0.09375 + cp[5] * 0.5625;
float3 ev01 = (cp[1] + cp[2] + cp[9] + cp[10]) * 0.0625 +
(cp[5] + cp[6]) * 0.375;
float3 vv1 = (cp[1] + cp[3] + cp[9] + cp[11]) * 0.015625 +
(cp[2] + cp[5] + cp[7] + cp[10]) * 0.09375 + cp[6] * 0.5625;
float3 ev12 = (cp[5] + cp[7] + cp[9] + cp[11]) * 0.0625 +
(cp[6] + cp[10]) * 0.375;
float3 vv2 = (cp[5] + cp[7] + cp[13] + cp[15]) * 0.015625 +
(cp[6] + cp[9] + cp[11] + cp[14]) * 0.09375 + cp[10] * 0.5625;
float3 ev23 = (cp[5] + cp[6] + cp[13] + cp[14]) * 0.0625 +
(cp[9] + cp[10]) * 0.375;
float3 vv3 = (cp[4] + cp[6] + cp[12] + cp[14]) * 0.015625 +
(cp[5] + cp[8] + cp[10] + cp[13]) * 0.09375 + cp[9] * 0.5625;
float3 ev03 = (cp[4] + cp[6] + cp[8] + cp[10]) * 0.0625 +
(cp[5] + cp[9]) * 0.375;
tessOuterLo = float4(0,0,0,0);
tessOuterHi = float4(0,0,0,0);
int transitionMask = OsdGetPatchTransitionMask(patchParam);
if ((transitionMask & 8) != 0) {
tessOuterLo[0] = OsdComputeTessLevel(vv0, ev03);
tessOuterHi[0] = OsdComputeTessLevel(vv3, ev03);
} else {
tessOuterLo[0] = OsdComputeTessLevel(cp[5], cp[9]);
}
if ((transitionMask & 1) != 0) {
tessOuterLo[1] = OsdComputeTessLevel(vv0, ev01);
tessOuterHi[1] = OsdComputeTessLevel(vv1, ev01);
} else {
tessOuterLo[1] = OsdComputeTessLevel(cp[5], cp[6]);
}
if ((transitionMask & 2) != 0) {
tessOuterLo[2] = OsdComputeTessLevel(vv1, ev12);
tessOuterHi[2] = OsdComputeTessLevel(vv2, ev12);
} else {
tessOuterLo[2] = OsdComputeTessLevel(cp[6], cp[10]);
}
if ((transitionMask & 4) != 0) {
tessOuterLo[3] = OsdComputeTessLevel(vv3, ev23);
tessOuterHi[3] = OsdComputeTessLevel(vv2, ev23);
} else {
tessOuterLo[3] = OsdComputeTessLevel(cp[9], cp[10]);
}
}
void
OsdGetTessLevelsLimitPoints(OsdPerPatchVertexBezier cpBezier[16],
int3 patchParam, out float4 tessOuterLo, out float4 tessOuterHi)
{
// Each edge of a transition patch is adjacent to one or two patches
// at the next refined level of subdivision. When the patch control
// points have been converted to the Bezier basis, the control points
// at the four corners are on the limit surface (since a Bezier patch
// interpolates its corner control points). We can compute an adaptive
// tessellation level for transition edges on the limit surface by
// evaluating a limit position at the mid point of each transition edge.
tessOuterLo = float4(0,0,0,0);
tessOuterHi = float4(0,0,0,0);
int transitionMask = OsdGetPatchTransitionMask(patchParam);
#if defined OSD_PATCH_ENABLE_SINGLE_CREASE
// PERFOMANCE: we just need to pick the correct corner points from P, P1, P2
float3 p0 = OsdEvalBezier(cpBezier, patchParam, float2(0.0, 0.0));
float3 p3 = OsdEvalBezier(cpBezier, patchParam, float2(1.0, 0.0));
float3 p12 = OsdEvalBezier(cpBezier, patchParam, float2(0.0, 1.0));
float3 p15 = OsdEvalBezier(cpBezier, patchParam, float2(1.0, 1.0));
if ((transitionMask & 8) != 0) {
float3 ev03 = OsdEvalBezier(cpBezier, patchParam, float2(0.0, 0.5));
tessOuterLo[0] = OsdComputeTessLevel(p0, ev03);
tessOuterHi[0] = OsdComputeTessLevel(p12, ev03);
} else {
tessOuterLo[0] = OsdComputeTessLevel(p0, p12);
}
if ((transitionMask & 1) != 0) {
float3 ev01 = OsdEvalBezier(cpBezier, patchParam, float2(0.5, 0.0));
tessOuterLo[1] = OsdComputeTessLevel(p0, ev01);
tessOuterHi[1] = OsdComputeTessLevel(p3, ev01);
} else {
tessOuterLo[1] = OsdComputeTessLevel(p0, p3);
}
if ((transitionMask & 2) != 0) {
float3 ev12 = OsdEvalBezier(cpBezier, patchParam, float2(1.0, 0.5));
tessOuterLo[2] = OsdComputeTessLevel(p3, ev12);
tessOuterHi[2] = OsdComputeTessLevel(p15, ev12);
} else {
tessOuterLo[2] = OsdComputeTessLevel(p3, p15);
}
if ((transitionMask & 4) != 0) {
float3 ev23 = OsdEvalBezier(cpBezier, patchParam, float2(0.5, 1.0));
tessOuterLo[3] = OsdComputeTessLevel(p12, ev23);
tessOuterHi[3] = OsdComputeTessLevel(p15, ev23);
} else {
tessOuterLo[3] = OsdComputeTessLevel(p12, p15);
}
#else
if ((transitionMask & 8) != 0) {
float3 ev03 = OsdEvalBezier(cpBezier, patchParam, float2(0.0, 0.5));
tessOuterLo[0] = OsdComputeTessLevel(cpBezier[0].P, ev03);
tessOuterHi[0] = OsdComputeTessLevel(cpBezier[12].P, ev03);
} else {
tessOuterLo[0] = OsdComputeTessLevel(cpBezier[0].P, cpBezier[12].P);
}
if ((transitionMask & 1) != 0) {
float3 ev01 = OsdEvalBezier(cpBezier, patchParam, float2(0.5, 0.0));
tessOuterLo[1] = OsdComputeTessLevel(cpBezier[0].P, ev01);
tessOuterHi[1] = OsdComputeTessLevel(cpBezier[3].P, ev01);
} else {
tessOuterLo[1] = OsdComputeTessLevel(cpBezier[0].P, cpBezier[3].P);
}
if ((transitionMask & 2) != 0) {
float3 ev12 = OsdEvalBezier(cpBezier, patchParam, float2(1.0, 0.5));
tessOuterLo[2] = OsdComputeTessLevel(cpBezier[3].P, ev12);
tessOuterHi[2] = OsdComputeTessLevel(cpBezier[15].P, ev12);
} else {
tessOuterLo[2] = OsdComputeTessLevel(cpBezier[3].P, cpBezier[15].P);
}
if ((transitionMask & 4) != 0) {
float3 ev23 = OsdEvalBezier(cpBezier, patchParam, float2(0.5, 1.0));
tessOuterLo[3] = OsdComputeTessLevel(cpBezier[12].P, ev23);
tessOuterHi[3] = OsdComputeTessLevel(cpBezier[15].P, ev23);
} else {
tessOuterLo[3] = OsdComputeTessLevel(cpBezier[12].P, cpBezier[15].P);
}
#endif
}
// Round up to the nearest even integer
float OsdRoundUpEven(float x) {
return 2*ceil(x/2);
}
// Round up to the nearest odd integer
float OsdRoundUpOdd(float x) {
return 2*ceil((x+1)/2)-1;
}
// Compute outer and inner tessellation levels taking into account the
// current tessellation spacing mode.
void
OsdComputeTessLevels(inout float4 tessOuterLo, inout float4 tessOuterHi,
out float4 tessLevelOuter, out float2 tessLevelInner)
{
// Outer levels are the sum of the Lo and Hi segments where the Hi
// segments will have lengths of zero for non-transition edges.
#if defined OSD_FRACTIONAL_EVEN_SPACING
// Combine fractional outer transition edge levels before rounding.
float4 combinedOuter = tessOuterLo + tessOuterHi;
// Round the segments of transition edges separately. We will recover the
// fractional parameterization of transition edges after tessellation.
tessLevelOuter = combinedOuter;
if (tessOuterHi[0] > 0) {
tessLevelOuter[0] =
OsdRoundUpEven(tessOuterLo[0]) + OsdRoundUpEven(tessOuterHi[0]);
}
if (tessOuterHi[1] > 0) {
tessLevelOuter[1] =
OsdRoundUpEven(tessOuterLo[1]) + OsdRoundUpEven(tessOuterHi[1]);
}
if (tessOuterHi[2] > 0) {
tessLevelOuter[2] =
OsdRoundUpEven(tessOuterLo[2]) + OsdRoundUpEven(tessOuterHi[2]);
}
if (tessOuterHi[3] > 0) {
tessLevelOuter[3] =
OsdRoundUpEven(tessOuterLo[3]) + OsdRoundUpEven(tessOuterHi[3]);
}
#elif defined OSD_FRACTIONAL_ODD_SPACING
// Combine fractional outer transition edge levels before rounding.
float4 combinedOuter = tessOuterLo + tessOuterHi;
// Round the segments of transition edges separately. We will recover the
// fractional parameterization of transition edges after tessellation.
//
// The sum of the two outer odd segment lengths will be an even number
// which the tessellator will increase by +1 so that there will be a
// total odd number of segments. We clamp the combinedOuter tess levels
// (used to compute the inner tess levels) so that the outer transition
// edges will be sampled without degenerate triangles.
tessLevelOuter = combinedOuter;
if (tessOuterHi[0] > 0) {
tessLevelOuter[0] =
OsdRoundUpOdd(tessOuterLo[0]) + OsdRoundUpOdd(tessOuterHi[0]);
combinedOuter = max(float4(3,3,3,3), combinedOuter);
}
if (tessOuterHi[1] > 0) {
tessLevelOuter[1] =
OsdRoundUpOdd(tessOuterLo[1]) + OsdRoundUpOdd(tessOuterHi[1]);
combinedOuter = max(float4(3,3,3,3), combinedOuter);
}
if (tessOuterHi[2] > 0) {
tessLevelOuter[2] =
OsdRoundUpOdd(tessOuterLo[2]) + OsdRoundUpOdd(tessOuterHi[2]);
combinedOuter = max(float4(3,3,3,3), combinedOuter);
}
if (tessOuterHi[3] > 0) {
tessLevelOuter[3] =
OsdRoundUpOdd(tessOuterLo[3]) + OsdRoundUpOdd(tessOuterHi[3]);
combinedOuter = max(float4(3,3,3,3), combinedOuter);
}
#else
// Round equally spaced transition edge levels before combining.
tessOuterLo = round(tessOuterLo);
tessOuterHi = round(tessOuterHi);
float4 combinedOuter = tessOuterLo + tessOuterHi;
tessLevelOuter = combinedOuter;
#endif
// Inner levels are the averages the corresponding outer levels.
tessLevelInner[0] = (combinedOuter[1] + combinedOuter[3]) * 0.5;
tessLevelInner[1] = (combinedOuter[0] + combinedOuter[2]) * 0.5;
}
void
OsdGetTessLevelsUniform(int3 patchParam,
out float4 tessLevelOuter, out float2 tessLevelInner,
out float4 tessOuterLo, out float4 tessOuterHi)
{
OsdGetTessLevelsUniform(patchParam, tessOuterLo, tessOuterHi);
OsdComputeTessLevels(tessOuterLo, tessOuterHi,
tessLevelOuter, tessLevelInner);
}
void
OsdGetTessLevelsAdaptiveRefinedPoints(float3 cpRefined[16], int3 patchParam,
out float4 tessLevelOuter, out float2 tessLevelInner,
out float4 tessOuterLo, out float4 tessOuterHi)
{
OsdGetTessLevelsRefinedPoints(cpRefined, patchParam,
tessOuterLo, tessOuterHi);
OsdComputeTessLevels(tessOuterLo, tessOuterHi,
tessLevelOuter, tessLevelInner);
}
void
OsdGetTessLevelsAdaptiveLimitPoints(OsdPerPatchVertexBezier cpBezier[16],
int3 patchParam,
out float4 tessLevelOuter, out float2 tessLevelInner,
out float4 tessOuterLo, out float4 tessOuterHi)
{
OsdGetTessLevelsLimitPoints(cpBezier, patchParam,
tessOuterLo, tessOuterHi);
OsdComputeTessLevels(tessOuterLo, tessOuterHi,
tessLevelOuter, tessLevelInner);
}
void
OsdGetTessLevels(float3 cp0, float3 cp1, float3 cp2, float3 cp3,
int3 patchParam,
out float4 tessLevelOuter, out float2 tessLevelInner)
{
float4 tessOuterLo = float4(0,0,0,0);
float4 tessOuterHi = float4(0,0,0,0);
#if defined OSD_ENABLE_SCREENSPACE_TESSELLATION
tessOuterLo[0] = OsdComputeTessLevel(cp0, cp1);
tessOuterLo[1] = OsdComputeTessLevel(cp0, cp3);
tessOuterLo[2] = OsdComputeTessLevel(cp2, cp3);
tessOuterLo[3] = OsdComputeTessLevel(cp1, cp2);
tessOuterHi = float4(0,0,0,0);
#else
OsdGetTessLevelsUniform(patchParam, tessOuterLo, tessOuterHi);
#endif
OsdComputeTessLevels(tessOuterLo, tessOuterHi,
tessLevelOuter, tessLevelInner);
}
#if defined OSD_FRACTIONAL_EVEN_SPACING || defined OSD_FRACTIONAL_ODD_SPACING
float
OsdGetTessFractionalSplit(float t, float level, float levelUp)
{
// Fractional tessellation of an edge will produce n segments where n
// is the tessellation level of the edge (level) rounded up to the
// nearest even or odd integer (levelUp). There will be n-2 segments of
// equal length (dx1) and two additional segments of equal length (dx0)
// that are typically shorter than the other segments. The two additional
// segments should be placed symmetrically on opposite sides of the
// edge (offset).
#if defined OSD_FRACTIONAL_EVEN_SPACING
if (level <= 2) return t;
float base = pow(2.0,floor(log2(levelUp)));
float offset = 1.0/(int(2*base-levelUp)/2 & int(base/2-1));
#elif defined OSD_FRACTIONAL_ODD_SPACING
if (level <= 1) return t;
float base = pow(2.0,floor(log2(levelUp)));
float offset = 1.0/(((int(2*base-levelUp)/2+1) & int(base/2-1))+1);
#endif
float dx0 = (1.0 - (levelUp-level)/2) / levelUp;
float dx1 = (1.0 - 2.0*dx0) / (levelUp - 2.0*ceil(dx0));
if (t < 0.5) {
float x = levelUp/2 - round(t*levelUp);
return 0.5 - (x*dx1 + int(x*offset > 1) * (dx0 - dx1));
} else if (t > 0.5) {
float x = round(t*levelUp) - levelUp/2;
return 0.5 + (x*dx1 + int(x*offset > 1) * (dx0 - dx1));
} else {
return t;
}
}
#endif
float
OsdGetTessTransitionSplit(float t, float lo, float hi)
{
#if defined OSD_FRACTIONAL_EVEN_SPACING
float loRoundUp = OsdRoundUpEven(lo);
float hiRoundUp = OsdRoundUpEven(hi);
// Convert the parametric t into a segment index along the combined edge.
float ti = round(t * (loRoundUp + hiRoundUp));
if (ti <= loRoundUp) {
float t0 = ti / loRoundUp;
return OsdGetTessFractionalSplit(t0, lo, loRoundUp) * 0.5;
} else {
float t1 = (ti - loRoundUp) / hiRoundUp;
return OsdGetTessFractionalSplit(t1, hi, hiRoundUp) * 0.5 + 0.5;
}
#elif defined OSD_FRACTIONAL_ODD_SPACING
float loRoundUp = OsdRoundUpOdd(lo);
float hiRoundUp = OsdRoundUpOdd(hi);
// Convert the parametric t into a segment index along the combined edge.
// The +1 below is to account for the extra segment produced by the
// tessellator since the sum of two odd tess levels will be rounded
// up by one to the next odd integer tess level.
float ti = round(t * (loRoundUp + hiRoundUp + 1));
if (ti <= loRoundUp) {
float t0 = ti / loRoundUp;
return OsdGetTessFractionalSplit(t0, lo, loRoundUp) * 0.5;
} else if (ti > (loRoundUp+1)) {
float t1 = (ti - (loRoundUp+1)) / hiRoundUp;
return OsdGetTessFractionalSplit(t1, hi, hiRoundUp) * 0.5 + 0.5;
} else {
return 0.5;
}
#else
// Convert the parametric t into a segment index along the combined edge.
float ti = round(t * (lo + hi));
if (ti <= lo) {
return (ti / lo) * 0.5;
} else {
return ((ti - lo) / hi) * 0.5 + 0.5;
}
#endif
}
float2
OsdGetTessParameterization(float2 uv, float4 tessOuterLo, float4 tessOuterHi)
{
float2 UV = uv;
if (UV.x == 0 && tessOuterHi[0] > 0) {
UV.y = OsdGetTessTransitionSplit(UV.y, tessOuterLo[0], tessOuterHi[0]);
} else
if (UV.y == 0 && tessOuterHi[1] > 0) {
UV.x = OsdGetTessTransitionSplit(UV.x, tessOuterLo[1], tessOuterHi[1]);
} else
if (UV.x == 1 && tessOuterHi[2] > 0) {
UV.y = OsdGetTessTransitionSplit(UV.y, tessOuterLo[2], tessOuterHi[2]);
} else
if (UV.y == 1 && tessOuterHi[3] > 0) {
UV.x = OsdGetTessTransitionSplit(UV.x, tessOuterLo[3], tessOuterHi[3]);
}
return UV;
}

4
opensubdiv/osd/hlslPatchShaderSource.cpp
View File

@ -36,6 +36,9 @@ namespace Osd {
static const char *commonShaderSource =
#include "hlslPatchCommon.gen.h"
;
static const char *commonTessShaderSource =
#include "hlslPatchCommonTess.gen.h"
;
static const char *patchLegacyShaderSource =
#include "hlslPatchLegacy.gen.h"
;
@ -63,6 +66,7 @@ std::string
HLSLPatchShaderSource::GetCommonShaderSource() {
std::stringstream ss;
ss << std::string(commonShaderSource);
ss << std::string(commonTessShaderSource);
ss << std::string(patchLegacyShaderSource);
return ss.str();
}