OpenSubdiv/opensubdiv/osd/hlslPtexCommon.hlsl
manuelk 791995cf32 Refactoring Ptex Mipmap and Analytic Displacement code
Moving Takahito's implementation into the core API:
- added <gl/d3d11>PtexCommon.<glsl/hlsl> shader code
- added control to enable Ptex common trunk in <gl/d3d11>DrawRegistryBase classes
- fixed GL & D3D11 ptexViewer examples to use the new API
2013-11-20 15:47:59 -08:00

327 lines
10 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.
//
//----------------------------------------------------------
// Ptex.Common
//----------------------------------------------------------
struct PtexPacking {
int page;
int nMipmap;
int uOffset;
int vOffset;
int adjSizeDiffs[4];
int width;
int height;
};
PtexPacking getPtexPacking(Buffer<int> packings, int faceID)
{
PtexPacking packing;
packing.page = packings[faceID*6+0].x;
packing.nMipmap = packings[faceID*6+1].x;
packing.uOffset = packings[faceID*6+2].x;
packing.vOffset = packings[faceID*6+3].x;
int wh = packings[faceID*6+5].x;
packing.width = 1 << (wh >> 8);
packing.height = 1 << (wh & 0xff);
int adjSizeDiffs = packings[faceID*6+4].x;
packing.adjSizeDiffs[0] = (adjSizeDiffs >> 12) & 0xf;
packing.adjSizeDiffs[1] = (adjSizeDiffs >> 8) & 0xf;
packing.adjSizeDiffs[2] = (adjSizeDiffs >> 4) & 0xf;
packing.adjSizeDiffs[3] = (adjSizeDiffs >> 0) & 0xf;
return packing;
}
int computeMipmapOffsetU(int w, int level)
{
int width = 1 << w;
int m = (0x55555555 & (width | (width-1))) << (w&1);
int x = ~((1 << (w -((level-1)&~1))) - 1);
return (m & x) + ((level+1)&~1);
}
int computeMipmapOffsetV(int h, int level)
{
int height = 1 << h;
int m = (0x55555555 & (height-1)) << ((h+1)&1);;
int x = ~((1 << (h - (level&~1))) - 1 );
return (m & x) + (level&~1);
}
PtexPacking getPtexPacking(Buffer<int> packings, int faceID, int level)
{
PtexPacking packing;
packing.page = packings[faceID*6+0].x;
packing.nMipmap = packings[faceID*6+1].x;
packing.uOffset = packings[faceID*6+2].x;
packing.vOffset = packings[faceID*6+3].x;
//int sizeDiffs = packings[faceID*6+4].x;
int wh = packings[faceID*6+5].x;
int w = wh >> 8;
int h = wh & 0xff;
// clamp max level
level = min(level, packing.nMipmap);
packing.uOffset += computeMipmapOffsetU(w, level);
packing.vOffset += computeMipmapOffsetV(h, level);
packing.width = 1 << (w-level);
packing.height = 1 << (h-level);
return packing;
}
void evalQuadraticBSpline(float u, out float B[3], out float BU[3])
{
B[0] = 0.5 * (u*u - 2.0*u + 1);
B[1] = 0.5 + u - u*u;
B[2] = 0.5 * u*u;
BU[0] = u - 1.0;
BU[1] = 1 - 2 * u;
BU[2] = u;
}
// ----------------------------------------------------------------------------
// Non-Mipmap Lookups
// ----------------------------------------------------------------------------
float4 PtexLookupNearest(float4 patchCoord,
Texture2DArray data,
Buffer<int> packings)
{
float2 uv = patchCoord.xy;
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID);
float2 coords = float2(uv.x * ppack.width + ppack.uOffset,
uv.y * ppack.height + ppack.vOffset);
return data[int3(int(coords.x), int(coords.y), ppack.page)];
}
float4 PtexLookupNearest(float4 patchCoord,
int level,
Texture2DArray data,
Buffer<int> packings)
{
float2 uv = patchCoord.xy;
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID, level);
float2 coords = float2(uv.x * ppack.width + ppack.uOffset,
uv.y * ppack.height + ppack.vOffset);
return data[int3(int(coords.x), int(coords.y), ppack.page)];
}
float4 PtexLookup(float4 patchCoord,
int level,
Texture2DArray data,
Buffer<int> packings)
{
float2 uv = patchCoord.xy;
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID, level);
float2 coords = float2(uv.x * ppack.width + ppack.uOffset,
uv.y * ppack.height + ppack.vOffset);
coords -= float2(0.5, 0.5);
int c0X = int(floor(coords.x));
int c1X = int(ceil(coords.x));
int c0Y = int(floor(coords.y));
int c1Y = int(ceil(coords.y));
float t = coords.x - float(c0X);
float s = coords.y - float(c0Y);
float4 d0 = data[int3(c0X, c0Y, ppack.page)];
float4 d1 = data[int3(c0X, c1Y, ppack.page)];
float4 d2 = data[int3(c1X, c0Y, ppack.page)];
float4 d3 = data[int3(c1X, c1Y, ppack.page)];
float4 result = (1-t) * ((1-s)*d0 + s*d1) + t * ((1-s)*d2 + s*d3);
return result;
}
float4 PtexLookupQuadratic(out float4 du,
out float4 dv,
float4 patchCoord,
int level,
Texture2DArray data,
Buffer<int> packings)
{
float2 uv = patchCoord.xy;
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID, level);
float2 coords = float2(uv.x * ppack.width + ppack.uOffset,
uv.y * ppack.height + ppack.vOffset);
coords -= float2(0.5, 0.5);
int cX = int(round(coords.x));
int cY = int(round(coords.y));
float x = 0.5 - (float(cX) - coords.x);
float y = 0.5 - (float(cY) - coords.y);
float4 d[9];
d[0] = data[int3(cX-1, cY-1, ppack.page)];
d[1] = data[int3(cX-1, cY-0, ppack.page)];
d[2] = data[int3(cX-1, cY+1, ppack.page)];
d[3] = data[int3(cX-0, cY-1, ppack.page)];
d[4] = data[int3(cX-0, cY-0, ppack.page)];
d[5] = data[int3(cX-0, cY+1, ppack.page)];
d[6] = data[int3(cX+1, cY-1, ppack.page)];
d[7] = data[int3(cX+1, cY-0, ppack.page)];
d[8] = data[int3(cX+1, cY+1, ppack.page)];
float B[3], D[3];
float4 BUCP[3], DUCP[3];
evalQuadraticBSpline(y, B, D);
for (int i = 0; i < 3; ++i) {
BUCP[i] = float4(0, 0, 0, 0);
DUCP[i] = float4(0, 0, 0, 0);
for (int j = 0; j < 3; j++) {
float4 A = d[i*3+j];
BUCP[i] += A * B[j];
DUCP[i] += A * D[j];
}
}
evalQuadraticBSpline(x, B, D);
float4 result = float4(0, 0, 0, 0);
du = float4(0, 0, 0, 0);
dv = float4(0, 0, 0, 0);
for (int i = 0; i < 3; ++i) {
result += B[i] * BUCP[i];
du += D[i] * BUCP[i];
dv += B[i] * DUCP[i];
}
du *= ppack.width;
dv *= ppack.height;
return result;
}
// ----------------------------------------------------------------------------
// MipMap Lookups
// ----------------------------------------------------------------------------
float4 PtexMipmapLookupNearest(float4 patchCoord,
int level,
Texture2DArray data,
Buffer<int> packings)
{
#if defined(SEAMLESS_MIPMAP)
// diff level
int faceID = int(patchCoord.w);
float2 uv = patchCoord.xy;
PtexPacking packing = getPtexPacking(packings, faceID);
level += lerp(lerp(packing.adjSizeDiffs[0], packing.adjSizeDiffs[1], uv.x),
lerp(packing.adjSizeDiffs[3], packing.adjSizeDiffs[2], uv.x),
uv.y);
#endif
int levelm = int(floor(level));
int levelp = int(ceil(level));
float t = level - float(levelm);
float4 result = (1-t) * PtexLookupNearest(patchCoord, levelm, data, packings)
+ t * PtexLookupNearest(patchCoord, levelp, data, packings);
return result;
}
float4 PtexMipmapLookup(float4 patchCoord,
float level,
Texture2DArray data,
Buffer<int> packings)
{
#if defined(SEAMLESS_MIPMAP)
// diff level
int faceID = int(patchCoord.w);
float2 uv = patchCoord.xy;
PtexPacking packing = getPtexPacking(packings, faceID);
level += lerp(lerp(packing.adjSizeDiffs[0], packing.adjSizeDiffs[1], uv.x),
lerp(packing.adjSizeDiffs[3], packing.adjSizeDiffs[2], uv.x),
uv.y);
#endif
int levelm = int(floor(level));
int levelp = int(ceil(level));
float t = level - float(levelm);
float4 result = (1-t) * PtexLookup(patchCoord, levelm, data, packings)
+ t * PtexLookup(patchCoord, levelp, data, packings);
return result;
}
float4 PtexMipmapLookupQuadratic(out float4 du,
out float4 dv,
float4 patchCoord,
float level,
Texture2DArray data,
Buffer<int> packings)
{
#if defined(SEAMLESS_MIPMAP)
// diff level
int faceID = int(patchCoord.w);
float2 uv = patchCoord.xy;
PtexPacking packing = getPtexPacking(packings, faceID);
level += lerp(lerp(packing.adjSizeDiffs[0], packing.adjSizeDiffs[1], uv.x),
lerp(packing.adjSizeDiffs[3], packing.adjSizeDiffs[2], uv.x),
uv.y);
#endif
int levelm = int(floor(level));
int levelp = int(ceil(level));
float t = level - float(levelm);
float4 du0, du1, dv0, dv1;
float4 r0 = PtexLookupQuadratic(du0, dv0, patchCoord, levelm, data, packings);
float4 r1 = PtexLookupQuadratic(du1, dv1, patchCoord, levelp, data, packings);
float4 result = lerp(r0, r1, t);
du = lerp(du0, du1, t);
dv = lerp(dv0, dv1, t);
return result;
}
float4 PtexMipmapLookupQuadratic(float4 patchCoord,
float level,
Texture2DArray data,
Buffer<int> packings)
{
float4 du, dv;
return PtexMipmapLookupQuadratic(du, dv, patchCoord, level, data, packings);
}