OpenSubdiv/examples/common/hlslPtexCommon.hlsl
Takahito Tejima 8fc0e5db93 Move Ptex code from osd to examples.
we're teasing out ptex specific data from core osd entities,
so there's no reason to keep ptex texturing utilities in core osd.
move them into example libs and let clients assemble shader snippets
as needed.

Also removing older ptex texturing code (without mipmap)
2015-05-07 13:56:48 -07:00

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<uint> 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<uint> 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<uint> 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<uint> 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<uint> 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<uint> 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] = {float4(0,0,0,0), float4(0,0,0,0), float4(0,0,0,0)},
DUCP[3] = {float4(0,0,0,0), float4(0,0,0,0), float4(0,0,0,0)};
evalQuadraticBSpline(y, B, D);
for (int i = 0; i < 3; ++i) {
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<uint> 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<uint> 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<uint> 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<uint> packings)
{
float4 du, dv;
return PtexMipmapLookupQuadratic(du, dv, patchCoord, level, data, packings);
}