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gfx3d: change lighting engine almost entirely to fixed point, and substantially improve accuracy of specular component

This commit is contained in:
zeromus 2010-07-03 11:35:10 +00:00
parent 25c2789ca5
commit 4dbec12893
4 changed files with 139 additions and 87 deletions
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138
desmume/src/gfx3d.cpp
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@ -385,7 +385,7 @@ u32 control = 0;
//light state:
static u32 lightColor[4] = {0,0,0,0};
static u32 lightDirection[4] = {0,0,0,0};
static s32 lightDirection[4] = {0,0,0,0};
//material state:
static u16 dsDiffuse, dsAmbient, dsSpecular, dsEmission;
//used for indexing the shininess table during parameters to shininess command
@ -400,8 +400,8 @@ static u32 envMode=0;
static u32 lightMask=0;
//other things:
static int texCoordinateTransform = 0;
static CACHE_ALIGN float cacheLightDirection[4][4];
static CACHE_ALIGN float cacheHalfVector[4][4];
static CACHE_ALIGN s32 cacheLightDirection[4][4];
static CACHE_ALIGN s32 cacheHalfVector[4][4];
//------------------
#define RENDER_FRONT_SURFACE 0x80
@ -587,7 +587,24 @@ void gfx3d_reset()
//=================================================================================
//=================================================================================
#define vec3dot(a, b) (((a[0]) * (b[0])) + ((a[1]) * (b[1])) + ((a[2]) * (b[2])))
inline float vec3dot(float* a, float* b) {
return (((a[0]) * (b[0])) + ((a[1]) * (b[1])) + ((a[2]) * (b[2])));
}
inline s32 mul_fixed32(s32 a, s32 b)
{
s64 temp = ((s64)a)*((s64)b);
return (s32)(temp>>12);
}
inline s32 vec3dot_fixed32(s32* a, s32* b) {
const s64 va[] = {a[0],a[1],a[2]};
const s64 vb[] = {b[0],b[1],b[2]};
s64 dot = va[0]*vb[0]+va[1]*vb[1]+va[2]*vb[2];
return (s32)(dot>>12);
}
#define SUBMITVERTEX(ii, nn) polylist->list[polylist->count].vertIndexes[ii] = tempVertInfo.map[nn];
//Submit a vertex to the GE
static void SetVertex()
@ -776,26 +793,46 @@ static void gfx3d_glTexImage_cache()
static void gfx3d_glLightDirection_cache(int index)
{
u32 v = lightDirection[index];
s32 v = lightDirection[index];
// Convert format into floating point value
cacheLightDirection[index][0] = normalTable[v&1023];
cacheLightDirection[index][1] = normalTable[(v>>10)&1023];
cacheLightDirection[index][2] = normalTable[(v>>20)&1023];
s16 x = ((v<<22)>>22)<<3;
s16 y = ((v<<12)>>22)<<3;
s16 z = ((v<<2)>>22)<<3;
cacheLightDirection[index][0] = x;
cacheLightDirection[index][1] = y;
cacheLightDirection[index][2] = z;
cacheLightDirection[index][3] = 0;
/* Multiply the vector by the directional matrix */
CACHE_ALIGN float temp[16] = {mtxCurrent[2][0]/4096.0f,mtxCurrent[2][1]/4096.0f,mtxCurrent[2][2]/4096.0f,mtxCurrent[2][3]/4096.0f,mtxCurrent[2][4]/4096.0f,mtxCurrent[2][5]/4096.0f,mtxCurrent[2][6]/4096.0f,mtxCurrent[2][7]/4096.0f,mtxCurrent[2][8]/4096.0f,mtxCurrent[2][9]/4096.0f,mtxCurrent[2][10]/4096.0f,mtxCurrent[2][11]/4096.0f,mtxCurrent[2][12]/4096.0f,mtxCurrent[2][13]/4096.0f,mtxCurrent[2][14]/4096.0f,mtxCurrent[2][15]/4096.0f};
MatrixMultVec3x3(temp, cacheLightDirection[index]);
//Multiply the vector by the directional matrix
MatrixMultVec3x3_fixed(mtxCurrent[2], cacheLightDirection[index]);
/* Calculate the half vector */
float lineOfSight[4] = {0.0f, 0.0f, -1.0f, 0.0f};
//Calculate the half angle vector
s32 lineOfSight[4] = {0, 0, (-1)<<12, 0};
for(int i = 0; i < 4; i++)
{
cacheHalfVector[index][i] = ((cacheLightDirection[index][i] + lineOfSight[i]) / 2.0f);
cacheHalfVector[index][i] = ((cacheLightDirection[index][i] + lineOfSight[i]));
}
//normalize the half angle vector
//can't believe the hardware really does this... but yet it seems...
s32 halfLength = ((s32)(sqrt((double)vec3dot_fixed32(cacheHalfVector[index],cacheHalfVector[index]))))<<6;
if(halfLength!=0)
{
halfLength = abs(halfLength);
halfLength >>= 6;
for(int i = 0; i < 4; i++)
{
s32 temp = cacheHalfVector[index][i];
temp <<= 6;
temp /= halfLength;
cacheHalfVector[index][i] = temp;
}
}
}
//===============================================================================
static void gfx3d_glMatrixMode(u32 v)
{
@ -1099,15 +1136,11 @@ static void gfx3d_glNormal(s32 v)
last_t = (s32)(((s64)nx * mtxCurrent[3][1] + (s64)ny * mtxCurrent[3][5] + (s64)nz * mtxCurrent[3][9] + (_t<<24))>>24);
}
CACHE_ALIGN float normal[4] = { nx/4096.0f, ny/4096.0f, nz/4096.0f, 1.0f };
CACHE_ALIGN s32 normal[4] = { nx,ny,nz,(1<<12) };
//use the current normal transform matrix
CACHE_ALIGN float temp[16] = {mtxCurrent[2][0]/4096.0f,mtxCurrent[2][1]/4096.0f,mtxCurrent[2][2]/4096.0f,mtxCurrent[2][3]/4096.0f,mtxCurrent[2][4]/4096.0f,mtxCurrent[2][5]/4096.0f,mtxCurrent[2][6]/4096.0f,mtxCurrent[2][7]/4096.0f,mtxCurrent[2][8]/4096.0f,mtxCurrent[2][9]/4096.0f,mtxCurrent[2][10]/4096.0f,mtxCurrent[2][11]/4096.0f,mtxCurrent[2][12]/4096.0f,mtxCurrent[2][13]/4096.0f,mtxCurrent[2][14]/4096.0f,mtxCurrent[2][15]/4096.0f};
MatrixMultVec3x3 (temp, normal);
MatrixMultVec3x3_fixed(mtxCurrent[2],normal);
//apply lighting model
{
u8 diffuse[3] = {
(dsDiffuse)&0x1F,
(dsDiffuse>>5)&0x1F,
@ -1139,39 +1172,48 @@ static void gfx3d_glNormal(s32 v)
(lightColor[i]>>5)&0x1F,
(lightColor[i]>>10)&0x1F };
/* This formula is the one used by the DS */
/* Reference : http://nocash.emubase.de/gbatek.htm#ds3dpolygonlightparameters */
//This formula is the one used by the DS
//Reference : http://nocash.emubase.de/gbatek.htm#ds3dpolygonlightparameters
s32 fixed_diffuse = std::max(0,-vec3dot_fixed32(cacheLightDirection[i],normal));
float diffuseLevel = std::max(0.0f, -vec3dot(cacheLightDirection[i], normal));
float shininessLevel = pow(std::max(0.0f, vec3dot(-cacheHalfVector[i], normal)), 2);
//todo - this could be cached in this form
s32 fixedTempNegativeHalf[] = {-cacheHalfVector[i][0],-cacheHalfVector[i][1],-cacheHalfVector[i][2],-cacheHalfVector[i][3]};
s32 dot = vec3dot_fixed32(fixedTempNegativeHalf, normal);
s32 fixedshininess = 0;
if(dot>0) //prevent shininess on opposite side
{
//we have cos(a). it seems that we need cos(2a). trig identity is a fast way to get it.
//cos^2(a)=(1/2)(1+cos(2a))
//2*cos^2(a)-1=cos(2a)
fixedshininess = 2*mul_fixed32(dot,dot)-4096;
//gbatek is almost right but not quite!
}
//this seems to need to be saturated, or else the table will overflow.
//even without a table, failure to saturate is bad news
fixedshininess = std::min(fixedshininess,4095);
fixedshininess = std::max(fixedshininess,0);
if(dsSpecular & 0x8000)
{
int shininessIndex = (int)(shininessLevel * 128);
if(shininessIndex >= (int)ARRAY_SIZE(gfx3d.state.shininessTable)) {
//we can't print this right now, because when a game triggers this it triggers it _A_LOT_
//so wait until we have per-frame diagnostics.
//this was tested using Princess Debut (US) after proceeding through the intro and getting the tiara.
//After much research, I determined that this was caused by the game feeding in a totally jacked matrix
//to mult4x4 from 0x02129B80 (after feeding two other valid matrices)
//the game seems to internally index these as: ?, 0x37, 0x2B <-- error
//but, man... this is seriously messed up. there must be something going wrong.
//maybe it has something to do with what looks like a mirror room effect that is going on during this time?
//PROGINFO("ERROR: shininess table out of bounds.\n maybe an emulator error; maybe a non-unit normal; setting to 0\n");
shininessIndex = 0;
}
shininessLevel = gfx3d.state.shininessTable[shininessIndex];
//shininess is 20.12 fixed point, so >>5 gives us .7 which is 128 entries
//the entries are 8bits each so <<4 gives us .12 again, compatible with the lighting formulas below
//(according to other normal nds procedures, we might should fill the bottom bits with 1 or 0 according to rules...)
fixedshininess = gfx3d.state.shininessTable[fixedshininess>>5]<<4;
}
for(int c = 0; c < 3; c++)
{
vertexColor[c] += (int)(((specular[c] * _lightColor[c] * shininessLevel)
+ (diffuse[c] * _lightColor[c] * diffuseLevel)
+ (ambient[c] * _lightColor[c])) / 31.0f);
s32 specComp = ((specular[c] * _lightColor[c] * fixedshininess)>>17); //5 bits for color*color and 12 bits for the shininess
s32 diffComp = ((diffuse[c] * _lightColor[c] * fixed_diffuse)>>17); //5bits for the color*color and 12 its for the diffuse
s32 ambComp = ((ambient[c] * _lightColor[c])>>5); //5bits for color*color
vertexColor[c] += specComp + diffComp + ambComp;
}
}
for(int c=0;c<3;c++)
{
colorRGB[c] = std::min(31,vertexColor[c]);
}
@ -1322,7 +1364,7 @@ static void gfx3d_glLightDirection (u32 v)
{
int index = v>>30;
lightDirection[index] = v;
lightDirection[index] = (s32)(v&0x3FFFFFFF);
gfx3d_glLightDirection_cache(index);
GFX_DELAY(6);
}
@ -1336,10 +1378,10 @@ static void gfx3d_glLightColor (u32 v)
static BOOL gfx3d_glShininess (u32 val)
{
gfx3d.state.shininessTable[shininessInd++] = ((val & 0xFF) / 256.0f);
gfx3d.state.shininessTable[shininessInd++] = (((val >> 8) & 0xFF) / 256.0f);
gfx3d.state.shininessTable[shininessInd++] = (((val >> 16) & 0xFF) / 256.0f);
gfx3d.state.shininessTable[shininessInd++] = (((val >> 24) & 0xFF) / 256.0f);
gfx3d.state.shininessTable[shininessInd++] = ((val & 0xFF));
gfx3d.state.shininessTable[shininessInd++] = (((val >> 8) & 0xFF));
gfx3d.state.shininessTable[shininessInd++] = (((val >> 16) & 0xFF));
gfx3d.state.shininessTable[shininessInd++] = (((val >> 24) & 0xFF));
if (shininessInd < 128) return FALSE;
shininessInd = 0;
@ -2336,7 +2378,7 @@ SFORMAT SF_GFX3D[]={
{ "GSFC", 4, 4, &gfx3d.state.fogColor},
{ "GSFO", 4, 1, &gfx3d.state.fogOffset},
{ "GST4", 2, 32, gfx3d.state.u16ToonTable},
{ "GSST", 4, 128, &gfx3d.state.shininessTable[0]},
{ "GSSU", 1, 128, &gfx3d.state.shininessTable[0]},
{ "GSSI", 4, 1, &shininessInd},
{ "GSAF", 4, 1, &gfx3d.state.activeFlushCommand},
{ "GSPF", 4, 1, &gfx3d.state.pendingFlushCommand},

2
desmume/src/gfx3d.h
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@ -350,7 +350,7 @@ struct GFX3D_State
bool invalidateToon;
u16 u16ToonTable[32];
float shininessTable[128];
u8 shininessTable[128];
};
struct Viewer3d_State

10
desmume/src/matrix.cpp
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@ -52,6 +52,16 @@ void MatrixMultVec4x4 (const s32 *matrix, s32 *vecPtr)
vecPtr[3] = (s32)((x * matrix[3] + y * matrix[7] + z * matrix[11] + w * matrix[15])>>12);
}
void MatrixMultVec3x3_fixed(const s32 *matrix, s32 *vecPtr)
{
s64 x = vecPtr[0];
s64 y = vecPtr[1];
s64 z = vecPtr[2];
vecPtr[0] = (s32)((x * matrix[0] + y * matrix[4] + z * matrix[ 8])>>12);
vecPtr[1] = (s32)((x * matrix[1] + y * matrix[5] + z * matrix[ 9])>>12);
vecPtr[2] = (s32)((x * matrix[2] + y * matrix[6] + z * matrix[10])>>12);
}
//-------------------------
//switched SSE functions: implementations for no SSE

2
desmume/src/matrix.h
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@ -223,7 +223,7 @@ FORCEINLINE void MatrixMultVec4x4_M2(const float *matrix, float *vecPtr)
MatrixMultVec4x4(matrix,vecPtr);
}
void MatrixMultVec3x3_fixed(const s32 *matrix, s32 *vecPtr);
FORCEINLINE void MatrixMultVec3x3(const float * matrix, float * vecPtr)
{
const __m128 vec = _mm_load_ps(vecPtr);