crossxtex/DirectXTex/DirectXTexNormalMaps.cpp

380 lines
12 KiB
C++

//-------------------------------------------------------------------------------------
// DirectXTexNormalMaps.cpp
//
// DirectX Texture Library - Normal map operations
//
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// http://go.microsoft.com/fwlink/?LinkId=248926
//-------------------------------------------------------------------------------------
#include "directxtexp.h"
namespace DirectX
{
#pragma prefast(suppress : 25000, "FXMVECTOR is 16 bytes")
static inline float _EvaluateColor( _In_ FXMVECTOR val, _In_ DWORD flags )
{
XMFLOAT4A f;
static XMVECTORF32 lScale = { 0.2125f, 0.7154f, 0.0721f, 1.f };
static_assert( CNMAP_CHANNEL_RED == 0x1, "CNMAP_CHANNEL_ flag values don't match mask" );
switch( flags & 0xf )
{
case 0:
case CNMAP_CHANNEL_RED: return XMVectorGetX( val );
case CNMAP_CHANNEL_GREEN: return XMVectorGetY( val );
case CNMAP_CHANNEL_BLUE: return XMVectorGetZ( val );
case CNMAP_CHANNEL_ALPHA: return XMVectorGetW( val );
case CNMAP_CHANNEL_LUMINANCE:
{
XMVECTOR v = XMVectorMultiply( val, lScale );
XMStoreFloat4A( &f, v );
return f.x + f.y + f.z;
}
break;
default:
assert(false);
return 0.f;
}
}
static void _EvaluateRow( _In_reads_(width) const XMVECTOR* pSource, _Out_writes_(width+2) float* pDest,
_In_ size_t width, _In_ DWORD flags )
{
assert( pSource && pDest );
assert( width > 0 );
for( size_t x = 0; x < width; ++x )
{
pDest[x+1] = _EvaluateColor( pSource[x], flags );
}
if ( flags & CNMAP_MIRROR_U )
{
// Mirror in U
pDest[0] = _EvaluateColor( pSource[0], flags );
pDest[width+1] = _EvaluateColor( pSource[width-1], flags );
}
else
{
// Wrap in U
pDest[0] = _EvaluateColor( pSource[width-1], flags );
pDest[width+1] = _EvaluateColor( pSource[0], flags );
}
}
static HRESULT _ComputeNMap( _In_ const Image& srcImage, _In_ DWORD flags, _In_ float amplitude,
_In_ DXGI_FORMAT format, _In_ const Image& normalMap )
{
if ( !srcImage.pixels || !normalMap.pixels )
return E_INVALIDARG;
assert( !IsCompressed(format) && !IsTypeless( format ) );
const DWORD convFlags = _GetConvertFlags( format );
if ( !convFlags )
return E_FAIL;
if ( !( convFlags & (CONVF_UNORM | CONVF_SNORM | CONVF_FLOAT) ) )
HRESULT_FROM_WIN32( ERROR_NOT_SUPPORTED );
const size_t width = srcImage.width;
const size_t height = srcImage.height;
if ( width != normalMap.width || height != normalMap.height )
return E_FAIL;
// Allocate temporary space (4 scanlines and 3 evaluated rows)
ScopedAlignedArrayXMVECTOR scanline( reinterpret_cast<XMVECTOR*>( _aligned_malloc( (sizeof(XMVECTOR)*width*4), 16 ) ) );
if ( !scanline )
return E_OUTOFMEMORY;
ScopedAlignedArrayFloat buffer( reinterpret_cast<float*>( _aligned_malloc( ( ( sizeof(float) * ( width + 2 ) ) * 3 ), 16 ) ) );
if ( !buffer )
return E_OUTOFMEMORY;
uint8_t* pDest = normalMap.pixels;
if ( !pDest )
return E_POINTER;
XMVECTOR* row0 = scanline.get();
XMVECTOR* row1 = row0 + width;
XMVECTOR* row2 = row1 + width;
XMVECTOR* target = row2 + width;
float* val0 = buffer.get();
float* val1 = val0 + width + 2;
float* val2 = val1 + width + 2;
const size_t rowPitch = srcImage.rowPitch;
const uint8_t* pSrc = srcImage.pixels;
// Read first scanline row into 'row1'
if ( !_LoadScanline( row1, width, pSrc, rowPitch, srcImage.format ) )
return E_FAIL;
// Setup 'row0'
if ( flags & CNMAP_MIRROR_V )
{
// Mirror first row
memcpy_s( row0, rowPitch, row1, rowPitch );
}
else
{
// Read last row (Wrap V)
if ( !_LoadScanline( row0, width, pSrc + (rowPitch * (height-1)), rowPitch, srcImage.format ) )
return E_FAIL;
}
// Evaluate the initial rows
_EvaluateRow( row0, val0, width, flags );
_EvaluateRow( row1, val1, width, flags );
pSrc += rowPitch;
for( size_t y = 0; y < height; ++y )
{
// Load next scanline of source image
if ( y < (height-1) )
{
if ( !_LoadScanline( row2, width, pSrc, rowPitch, srcImage.format ) )
return E_FAIL;
}
else
{
if ( flags & CNMAP_MIRROR_V )
{
// Use last row of source image
if ( !_LoadScanline( row2, width, srcImage.pixels + (rowPitch * (height-1)), rowPitch, srcImage.format ) )
return E_FAIL;
}
else
{
// Use first row of source image (Wrap V)
if ( !_LoadScanline( row2, width, srcImage.pixels, rowPitch, srcImage.format ) )
return E_FAIL;
}
}
// Evaluate row
_EvaluateRow( row2, val2, width, flags );
// Generate target scanline
XMVECTOR *dptr = target;
for( size_t x = 0; x < width; ++x )
{
// Compute normal via central differencing
float totDelta = ( val0[x] - val0[x+2] ) + ( val1[x] - val1[x+2] ) + ( val2[x] - val2[x+2] );
float deltaZX = totDelta * amplitude / 6.f;
totDelta = ( val0[x] - val2[x] ) + ( val0[x+1] - val2[x+1] ) + ( val0[x+2] - val2[x+2] );
float deltaZY = totDelta * amplitude / 6.f;
XMVECTOR vx = XMVectorSetZ( g_XMNegIdentityR0, deltaZX ); // (-1.0f, 0.0f, deltaZX)
XMVECTOR vy = XMVectorSetZ( g_XMNegIdentityR1, deltaZY ); // (0.0f, -1.0f, deltaZY)
XMVECTOR normal = XMVector3Normalize( XMVector3Cross( vx, vy ) );
// Compute alpha (1.0 or an occlusion term)
float alpha = 1.f;
if ( flags & CNMAP_COMPUTE_OCCLUSION )
{
float delta = 0.f;
float c = val1[x+1];
float t = val0[x] - c; if ( t > 0.f ) delta += t;
t = val0[x+1] - c; if ( t > 0.f ) delta += t;
t = val0[x+2] - c; if ( t > 0.f ) delta += t;
t = val1[x] - c; if ( t > 0.f ) delta += t;
// Skip current pixel
t = val1[x+2] - c; if ( t > 0.f ) delta += t;
t = val2[x] - c; if ( t > 0.f ) delta += t;
t = val2[x+1] - c; if ( t > 0.f ) delta += t;
t = val2[x+2] - c; if ( t > 0.f ) delta += t;
// Average delta (divide by 8, scale by amplitude factor)
delta *= 0.125f * amplitude;
if ( delta > 0.f )
{
// If < 0, then no occlusion
float r = sqrtf( 1.f + delta*delta );
alpha = (r - delta) / r;
}
}
// Encode based on target format
if ( convFlags & CONVF_UNORM )
{
// 0.5f*normal + 0.5f -or- invert sign case: -0.5f*normal + 0.5f
XMVECTOR n1 = XMVectorMultiplyAdd( (flags & CNMAP_INVERT_SIGN) ? g_XMNegativeOneHalf : g_XMOneHalf, normal, g_XMOneHalf );
*dptr++ = XMVectorSetW( n1, alpha );
}
else if ( flags & CNMAP_INVERT_SIGN )
{
*dptr++ = XMVectorSetW( XMVectorNegate( normal ), alpha );
}
else
{
*dptr++ = XMVectorSetW( normal, alpha );
}
}
if ( !_StoreScanline( pDest, normalMap.rowPitch, format, target, width ) )
return E_FAIL;
// Cycle buffers
float* temp = val0;
val0 = val1;
val1 = val2;
val2 = temp;
pSrc += rowPitch;
pDest += normalMap.rowPitch;
}
return S_OK;
}
//=====================================================================================
// Entry points
//=====================================================================================
//-------------------------------------------------------------------------------------
// Generates a normal map from a height-map
//-------------------------------------------------------------------------------------
_Use_decl_annotations_
HRESULT ComputeNormalMap( const Image& srcImage, DWORD flags, float amplitude,
DXGI_FORMAT format, ScratchImage& normalMap )
{
if ( !srcImage.pixels || !IsValid(format) || IsCompressed( format ) || IsTypeless( format ) )
return E_INVALIDARG;
static_assert( CNMAP_CHANNEL_RED == 0x1, "CNMAP_CHANNEL_ flag values don't match mask" );
switch( flags & 0xf )
{
case 0:
case CNMAP_CHANNEL_RED:
case CNMAP_CHANNEL_GREEN:
case CNMAP_CHANNEL_BLUE:
case CNMAP_CHANNEL_ALPHA:
case CNMAP_CHANNEL_LUMINANCE:
break;
default:
return E_INVALIDARG;
}
if ( IsCompressed( srcImage.format ) || IsTypeless( srcImage.format ) )
return HRESULT_FROM_WIN32( ERROR_NOT_SUPPORTED );
// Setup target image
normalMap.Release();
HRESULT hr = normalMap.Initialize2D( format, srcImage.width, srcImage.height, 1, 1 );
if ( FAILED(hr) )
return hr;
const Image *img = normalMap.GetImage( 0, 0, 0 );
if ( !img )
{
normalMap.Release();
return E_POINTER;
}
hr = _ComputeNMap( srcImage, flags, amplitude, format, *img );
if ( FAILED(hr) )
{
normalMap.Release();
return hr;
}
return S_OK;
}
_Use_decl_annotations_
HRESULT ComputeNormalMap( const Image* srcImages, size_t nimages, const TexMetadata& metadata,
DWORD flags, float amplitude, DXGI_FORMAT format, ScratchImage& normalMaps )
{
if ( !srcImages || !nimages )
return E_INVALIDARG;
if ( !IsValid(format) || IsCompressed(format) || IsTypeless(format) )
return E_INVALIDARG;
static_assert( CNMAP_CHANNEL_RED == 0x1, "CNMAP_CHANNEL_ flag values don't match mask" );
switch( flags & 0xf )
{
case 0:
case CNMAP_CHANNEL_RED:
case CNMAP_CHANNEL_GREEN:
case CNMAP_CHANNEL_BLUE:
case CNMAP_CHANNEL_ALPHA:
case CNMAP_CHANNEL_LUMINANCE:
break;
default:
return E_INVALIDARG;
}
normalMaps.Release();
TexMetadata mdata2 = metadata;
mdata2.format = format;
HRESULT hr = normalMaps.Initialize( mdata2 );
if ( FAILED(hr) )
return hr;
if ( nimages != normalMaps.GetImageCount() )
{
normalMaps.Release();
return E_FAIL;
}
const Image* dest = normalMaps.GetImages();
if ( !dest )
{
normalMaps.Release();
return E_POINTER;
}
for( size_t index=0; index < nimages; ++index )
{
assert( dest[ index ].format == format );
const Image& src = srcImages[ index ];
if ( IsCompressed( src.format ) || IsTypeless( src.format ) )
{
normalMaps.Release();
return HRESULT_FROM_WIN32( ERROR_NOT_SUPPORTED );
}
if ( src.width != dest[ index ].width || src.height != dest[ index ].height )
{
normalMaps.Release();
return E_FAIL;
}
hr = _ComputeNMap( src, flags, amplitude, format, dest[ index ] );
if ( FAILED(hr) )
{
normalMaps.Release();
return hr;
}
}
return S_OK;
}
}; // namespace