Serious-Engine/Sources/Engine/Graphics/Fog.cpp

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/* Copyright (c) 2002-2012 Croteam Ltd. All rights reserved. */
#include "Engine/StdH.h"
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#include <Engine/Base/Memory.h>
#include <Engine/Base/FileName.h>
#include <Engine/Base/Statistics_Internal.h>
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#include <Engine/Math/Matrix.h>
#include <Engine/Math/Functions.h>
#include <Engine/Graphics/Color.h>
#include <Engine/Graphics/GfxLibrary.h>
#include <Engine/Graphics/Fog_internal.h>
#include <Engine/Graphics/GfxProfile.h>
#include <Engine/Graphics/ImageInfo.h>
// asm shortcuts
#define O offset
#define Q qword ptr
#define D dword ptr
#define W word ptr
#define B byte ptr
// current fog parameters
BOOL _fog_bActive = FALSE;
CFogParameters _fog_fp;
CTexParams _fog_tpLocal;
FLOAT _fog_fViewerH = 0.0f;
FLOAT3D _fog_vViewPosAbs;
FLOAT3D _fog_vViewDirAbs;
FLOAT3D _fog_vHDirAbs;
FLOAT3D _fog_vHDirView;
FLOAT _fog_fMulZ=0;
FLOAT _fog_fMulH=0;
FLOAT _fog_fAddH=0;
ULONG _fog_ulAlpha=0;
ULONG _fog_ulTexture=0;
ULONG _fog_ulFormat=0;
PIX _fog_pixSizeH=0;
PIX _fog_pixSizeL=0;
FLOAT _fog_fStart=0; // where in height fog starts
FLOAT _fog_fEnd=0; // where in height fog ends
UBYTE *_fog_pubTable=NULL;
extern INDEX gfx_bRenderFog;
extern BOOL _bMultiPlayer;
// prepares fog and haze parameters and eventualy converts texture
ULONG PrepareTexture( UBYTE *pubTexture, PIX pixSizeI, PIX pixSizeJ)
{
// need to upload from RGBA format
const PIX pixTextureSize = pixSizeI*pixSizeJ;
#if (defined USE_PORTABLE_C)
STUBBED("PrepareTexture");
#elif (defined __MSVC_INLINE__)
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__asm {
mov esi,D [pubTexture]
mov edi,D [pubTexture]
mov ecx,D [pixTextureSize]
lea edi,[esi+ecx]
pixLoop:
movzx eax,B [esi]
or eax,0xFFFFFF00
bswap eax
mov D [edi],eax
add esi,1
add edi,4
dec ecx
jnz pixLoop
}
#elif (defined __GNU_INLINE__)
__asm__ __volatile__ (
"leal 0(%%esi, %%ecx), %%edi \n\t"
"0: \n\t" // pixLoop
"movzbl (%%esi), %%eax \n\t"
"orl $0xFFFFFF00, %%eax \n\t"
"bswapl %%eax \n\t"
"movl %%eax, (%%edi) \n\t"
"addl $1, %%esi \n\t"
"addl $4, %%edi \n\t"
"decl %%ecx \n\t"
"jnz 0b \n\t" // pixLoop
: // no outputs.
: "S" (pubTexture), "D" (pubTexture), "c" (pixTextureSize)
: "eax", "cc", "memory"
);
#else
#error Write inline ASM for your platform.
#endif
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// determine internal format
extern INDEX gap_bAllowGrayTextures;
extern INDEX tex_bFineFog;
if( gap_bAllowGrayTextures) return TS.ts_tfLA8;
if( tex_bFineFog) return TS.ts_tfRGBA8;
return TS.ts_tfRGBA4;
}
// start fog with given parameters
void StartFog( CFogParameters &fp, const FLOAT3D &vViewPosAbs, const FLOATmatrix3D &mAbsToView)
{
ASSERT( !_fog_bActive);
if( _bMultiPlayer) gfx_bRenderFog = 1;
if( !gfx_bRenderFog) return;
_fog_bActive = TRUE;
_fog_fp = fp;
_fog_vHDirAbs = -_fog_fp.fp_vFogDir;
_fog_vViewPosAbs = vViewPosAbs;
_fog_vViewDirAbs(1) = -mAbsToView(3, 1);
_fog_vViewDirAbs(2) = -mAbsToView(3, 2);
_fog_vViewDirAbs(3) = -mAbsToView(3, 3);
_fog_fViewerH = _fog_vViewPosAbs%-_fog_fp.fp_vFogDir;
_fog_vHDirView = _fog_vHDirAbs*mAbsToView;
// calculate fog mapping factors
_fog_fMulZ = 1/(_fog_fp.fp_fFar);
_fog_fMulH = 1/(_fog_fp.fp_fH3-_fog_fp.fp_fH0);
_fog_fAddH = _fog_fp.fp_fH3+_fog_fViewerH;
// calculate fog table size wanted
extern INDEX tex_iFogSize;
tex_iFogSize = Clamp( tex_iFogSize, 4L, 8L);
PIX pixSizeH = ClampUp( _fog_fp.fp_iSizeH, 1L<<tex_iFogSize);
PIX pixSizeL = ClampUp( _fog_fp.fp_iSizeL, 1L<<tex_iFogSize);
BOOL bNoDiscard = TRUE;
// if fog table is not allocated in right size
if( (_fog_pixSizeH!=pixSizeH || _fog_pixSizeL!=pixSizeL) && _fog_pubTable!=NULL) {
FreeMemory( _fog_pubTable); // free it
_fog_pubTable = NULL;
}
// allocate table if needed
if( _fog_pubTable==NULL) {
// allocate byte table (for intensity values) and ULONG table (color values for uploading) right behind!
_fog_pubTable = (UBYTE*)AllocMemory( pixSizeH*pixSizeL * (sizeof(UBYTE)+sizeof(ULONG)));
_fog_pixSizeH = pixSizeH;
_fog_pixSizeL = pixSizeL;
_fog_tpLocal.Clear();
bNoDiscard = FALSE;
}
// update fog alpha value
_fog_ulAlpha = (_fog_fp.fp_colColor&CT_AMASK)>>CT_ASHIFT;
// get parameters
const FLOAT fH0 = _fog_fp.fp_fH0; // lowest point in LUT ->texture t=1
const FLOAT fH1 = _fog_fp.fp_fH1; // bottom of fog in LUT
const FLOAT fH2 = _fog_fp.fp_fH2; // top of fog in LUT
const FLOAT fH3 = _fog_fp.fp_fH3; // highest point in LUT ->texture t=0
const FLOAT fFar = _fog_fp.fp_fFar; // farthest point in LUT ->texture s=1
const FLOAT fDensity = _fog_fp.fp_fDensity;
const AttenuationType at = _fog_fp.fp_atType;
const FogGraduationType fgt = _fog_fp.fp_fgtType;
const FLOAT fHFogSize = fH2-fH1;
const FLOAT fHV = -_fog_fViewerH;
const FLOAT fEpsilon = 0.001f;
ASSERT( fHFogSize>0);
// for each row (height in fog)
for( PIX pixH=0; pixH<pixSizeH; pixH++)
{
// get fog height of the point from row coordinate in texture
FLOAT fHP = fH3+FLOAT(pixH)/pixSizeH*(fH0-fH3);
// sort viewer and point and get A (lower) and B (higher) fog coord
// making sure that they are never same
FLOAT fHA, fHB;
if (fHP<fHV-fEpsilon) {
fHA=fHP;
fHB=fHV;
} else if (fHP>fHV+fEpsilon) {
fHA=fHV;
fHB=fHP;
} else {
fHA=fHV-fEpsilon;
fHB=fHP+fEpsilon;
}
// get distance between the two points in height axis
FLOAT fDH = fHB-fHA;
FLOAT fOoDH = 1/fDH;
// calculate relative part of height that goes through the fog
FLOAT fA2 = (fH2-fHA)*fOoDH;
fA2 = Clamp(fA2,0.0f,1.0f);
FLOAT fA1 = (fH1-fHA)*fOoDH;
fA1 = Clamp(fA1,0.0f,1.0f);
FLOAT fA = fA2-fA1;
fA = Clamp(fA,0.0f,1.0f);
// if not constant graduation
if( fgt!=FGT_CONSTANT) {
// calculate fog height for two points, limited to be inside fog
FLOAT fFH0 = (fHFogSize-Clamp(fHA-fH1, 0.0f, fHFogSize));
FLOAT fFH1 = (fHFogSize-Clamp(fHB-fH1, 0.0f, fHFogSize));
// multiply the heights by graduation factor
fFH0 *= _fog_fp.fp_fGraduation;
fFH1 *= _fog_fp.fp_fGraduation;
FLOAT fDens;
// if linear graduation
if (fgt==FGT_LINEAR) {
// get linear integrated density factor
fDens = (fFH0+fFH1)/2.0f;
// if exponential graduation
} else {
ASSERT(fgt==FGT_EXP);
// sort the two heights and make sure they are not same
FLOAT fFA, fFB;
if (fFH0<fFH1-fEpsilon) {
fFA=fFH0;
fFB=fFH1;
} else if (fFH0>fFH1+fEpsilon) {
fFA=fFH1;
fFB=fFH0;
} else {
fFA=fFH1-fEpsilon;
fFB=fFH0+fEpsilon;
}
// calculate exponential integrated density factor normally
fDens = 1.0f+(exp(-fFB)-exp(-fFA))/(fFB-fFA);
}
// limit the intergrated density factor
fDens = Clamp(fDens, 0.0f, 1.0f);
// relative size multiplied by integrated density factor gives total fog sum
fA *= fDens;
}
// do per-row loop
switch(at)
{
// linear fog
case AT_LINEAR: {
// calculate linear step for the fog parameter
FLOAT fT = 0.0f;
FLOAT fTStep = 1.0f/pixSizeL *fFar*fDensity*fA *255;
// fog is just clamped fog parameter in each pixel
for( INDEX pixL=0; pixL<pixSizeL; pixL++) {
_fog_pubTable[pixH*pixSizeL+pixL] = Clamp( FloatToInt(fT), 0L, 255L);
fT += fTStep;
}
} break;
// exp fog
case AT_EXP: {
// calculate linear step for the fog parameter
FLOAT fT = 0.0f;
FLOAT fTStep = 1.0f/pixSizeL*fFar*fDensity*fA;
// fog is exp(-t) function of fog parameter, now calculate
// step (actually multiplication) for the fog
FLOAT fExp = 255.0f;
FLOAT fExpMul = exp(-fTStep);
for( INDEX pixL=0; pixL<pixSizeL; pixL++) {
_fog_pubTable[pixH*pixSizeL+pixL] = 255-FloatToInt(fExp);
fExp *= fExpMul;
}
} break;
case AT_EXP2: {
// calculate linear step for the fog parameter
FLOAT fT = 0.0f;
FLOAT fTStep = 1.0f/pixSizeL*fFar*fDensity*fA;
// fog is exp(-t^2) function of fog parameter, now calculate
// first and second order step (actually multiplication) for the fog
FLOAT fExp2 = 255.0f;
FLOAT fExp2Mul = exp(-fTStep*fTStep);
FLOAT fExp2MulMul = exp(-2*fTStep*fTStep);
for( INDEX pixL=0; pixL<pixSizeL; pixL++) {
_fog_pubTable[pixH*pixSizeL+pixL] = 255-FloatToInt(fExp2);
fExp2 *= fExp2Mul;
fExp2Mul *= fExp2MulMul;
}
} break;
}
}
// determine where fog starts and ends
_fog_fStart = LowerLimit(0.0f);
_fog_fEnd = UpperLimit(0.0f);
INDEX pix;
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if( _fog_pubTable[pixSizeL-1]) {
// going from bottom
for( pix=pixSizeH-1; pix>0; pix--) {
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if( (_fog_pubTable[(pix+1)*pixSizeL-1]*_fog_ulAlpha)>>8) break;
}
if( pix<(pixSizeH-1)) _fog_fEnd = (FLOAT)(pix+1) / (FLOAT)(pixSizeH-1);
} else {
// going from top
for( pix=0; pix<pixSizeH; pix++) {
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if( (_fog_pubTable[(pix+1)*pixSizeL-1]*_fog_ulAlpha)>>8) break;
}
if( pix>0) _fog_fStart = (FLOAT)(pix-1) / (FLOAT)(pixSizeH-1);
}
// prepare and upload the fog table
_fog_tpLocal.tp_bSingleMipmap = TRUE;
const ULONG ulFormat = PrepareTexture( _fog_pubTable, _fog_pixSizeL, _fog_pixSizeH);
if( _fog_ulFormat!=ulFormat) {
_fog_ulFormat = ulFormat;
bNoDiscard = FALSE;
} // set'n'upload
gfxSetTextureWrapping( GFX_CLAMP, GFX_CLAMP);
gfxSetTexture( _fog_ulTexture, _fog_tpLocal);
gfxUploadTexture( (ULONG*)(_fog_pubTable + _fog_pixSizeL*_fog_pixSizeH),
_fog_pixSizeL, _fog_pixSizeH, ulFormat, bNoDiscard);
}
// stop fog
void StopFog(void)
{
_fog_bActive = FALSE;
}
// current haze parameters
BOOL _haze_bActive = FALSE;
CHazeParameters _haze_hp;
CTexParams _haze_tpLocal;
PIX _haze_pixSize=0;
FLOAT _haze_fStart=0; // where in depth haze starts
UBYTE *_haze_pubTable=NULL;
FLOAT3D _haze_vViewPosAbs;
FLOAT3D _haze_vViewDirAbs;
FLOAT _haze_fMul=0;
FLOAT _haze_fAdd=0;
ULONG _haze_ulAlpha=0;
ULONG _haze_ulTexture=0;
ULONG _haze_ulFormat=0;
// start haze with given parameters
void StartHaze( CHazeParameters &hp,
const FLOAT3D &vViewPosAbs, const FLOATmatrix3D &mAbsToView)
{
ASSERT( !_haze_bActive);
if( _bMultiPlayer) gfx_bRenderFog = 1;
if( !gfx_bRenderFog) return;
_haze_bActive = TRUE;
_haze_hp = hp;
_haze_vViewPosAbs = vViewPosAbs;
_haze_vViewDirAbs(1) = -mAbsToView(3, 1);
_haze_vViewDirAbs(2) = -mAbsToView(3, 2);
_haze_vViewDirAbs(3) = -mAbsToView(3, 3);
// calculate haze mapping factors
_haze_fMul = 1/(_haze_hp.hp_fFar-_haze_hp.hp_fNear);
_haze_fAdd = -_haze_hp.hp_fNear;
PIX pixSize = _haze_hp.hp_iSize;
BOOL bNoDiscard = TRUE;
// if haze table is not allocated in right size
if( _haze_pixSize!=pixSize && _haze_pubTable!=NULL) {
FreeMemory( _haze_pubTable); // free it
_haze_pubTable = NULL;
}
// allocate table if needed
if( _haze_pubTable==NULL) {
// allocate byte table (for intensity values) and ULONG table (color values for uploading) right behind!
_haze_pubTable = (UBYTE*)AllocMemory(pixSize *(sizeof(UBYTE)+sizeof(ULONG)));
_haze_pixSize = pixSize;
_haze_tpLocal.Clear();
bNoDiscard = FALSE;
}
// update fog alpha value
_haze_ulAlpha = (_haze_hp.hp_colColor&CT_AMASK)>>CT_ASHIFT;
// get parameters
FLOAT fNear = _haze_hp.hp_fNear;
FLOAT fFar = _haze_hp.hp_fFar;
FLOAT fDensity = _haze_hp.hp_fDensity;
AttenuationType at = _haze_hp.hp_atType;
// generate table
INDEX pix;
for( pix=0; pix<pixSize; pix++) {
FLOAT fD = FLOAT(pix)/pixSize*(fFar-fNear);
FLOAT fT = fDensity*fD;
FLOAT fHaze=0.0f;
switch(at) {
case AT_LINEAR: fHaze = Clamp(fT,0.0f,1.0f); break;
case AT_EXP: fHaze = 1-exp(-fT); break;
case AT_EXP2: fHaze = 1-exp(-fT*fT); break;
}
const UBYTE ubValue = NormFloatToByte(fHaze);
_haze_pubTable[pix] = ubValue;
}
// determine where haze starts
for( pix=1; pix<pixSize; pix++) if( (_haze_pubTable[pix]*_haze_ulAlpha)>>8) break;
_haze_fStart = (FLOAT)(pix-1) / (FLOAT)(pixSize-1);
// prepare haze table
_haze_tpLocal.tp_bSingleMipmap = TRUE;
const ULONG ulFormat = PrepareTexture( _haze_pubTable, _haze_pixSize, 1);
if( _haze_ulFormat!=ulFormat) {
_haze_ulFormat = ulFormat;
bNoDiscard = FALSE;
} // set'n'upload
gfxSetTextureWrapping( GFX_CLAMP, GFX_CLAMP);
gfxSetTexture( _haze_ulTexture, _haze_tpLocal);
gfxUploadTexture( (ULONG*)(_haze_pubTable + _haze_pixSize*1), _haze_pixSize, 1, ulFormat, bNoDiscard);
}
// stop haze
void StopHaze(void)
{
_haze_bActive = FALSE;
}