bsnes/asnes/chip/cx4/functions.cpp

252 lines
7.1 KiB
C++
Executable File

#ifdef CX4_CPP
#include <math.h>
#define Tan(a) (CosTable[a] ? ((((int32)SinTable[a]) << 16) / CosTable[a]) : 0x80000000)
#define sar(b, n) ((b) >> (n))
#ifdef PI
#undef PI
#endif
#define PI 3.1415926535897932384626433832795
//Wireframe Helpers
void Cx4::C4TransfWireFrame() {
double c4x = (double)C4WFXVal;
double c4y = (double)C4WFYVal;
double c4z = (double)C4WFZVal - 0x95;
double tanval, c4x2, c4y2, c4z2;
//Rotate X
tanval = -(double)C4WFX2Val * PI * 2 / 128;
c4y2 = c4y * ::cos(tanval) - c4z * ::sin(tanval);
c4z2 = c4y * ::sin(tanval) + c4z * ::cos(tanval);
//Rotate Y
tanval = -(double)C4WFY2Val * PI * 2 / 128;
c4x2 = c4x * ::cos(tanval) + c4z2 * ::sin(tanval);
c4z = c4x * -::sin(tanval) + c4z2 * ::cos(tanval);
//Rotate Z
tanval = -(double)C4WFDist * PI * 2 / 128;
c4x = c4x2 * ::cos(tanval) - c4y2 * ::sin(tanval);
c4y = c4x2 * ::sin(tanval) + c4y2 * ::cos(tanval);
//Scale
C4WFXVal = (int16)(c4x * C4WFScale / (0x90 * (c4z + 0x95)) * 0x95);
C4WFYVal = (int16)(c4y * C4WFScale / (0x90 * (c4z + 0x95)) * 0x95);
}
void Cx4::C4CalcWireFrame() {
C4WFXVal = C4WFX2Val - C4WFXVal;
C4WFYVal = C4WFY2Val - C4WFYVal;
if(abs(C4WFXVal) > abs(C4WFYVal)) {
C4WFDist = abs(C4WFXVal) + 1;
C4WFYVal = (256 * (long)C4WFYVal) / abs(C4WFXVal);
C4WFXVal = (C4WFXVal < 0) ? -256 : 256;
} else if(C4WFYVal != 0) {
C4WFDist = abs(C4WFYVal) + 1;
C4WFXVal = (256 * (long)C4WFXVal) / abs(C4WFYVal);
C4WFYVal = (C4WFYVal < 0) ? -256 : 256;
} else {
C4WFDist = 0;
}
}
void Cx4::C4TransfWireFrame2() {
double c4x = (double)C4WFXVal;
double c4y = (double)C4WFYVal;
double c4z = (double)C4WFZVal;
double tanval, c4x2, c4y2, c4z2;
//Rotate X
tanval = -(double)C4WFX2Val * PI * 2 / 128;
c4y2 = c4y * ::cos(tanval) - c4z * ::sin(tanval);
c4z2 = c4y * ::sin(tanval) + c4z * ::cos(tanval);
//Rotate Y
tanval = -(double)C4WFY2Val * PI * 2 / 128;
c4x2 = c4x * ::cos(tanval) + c4z2 * ::sin(tanval);
c4z = c4x * -::sin(tanval) + c4z2 * ::cos(tanval);
//Rotate Z
tanval = -(double)C4WFDist * PI * 2 / 128;
c4x = c4x2 * ::cos(tanval) - c4y2 * ::sin(tanval);
c4y = c4x2 * ::sin(tanval) + c4y2 * ::cos(tanval);
//Scale
C4WFXVal = (int16)(c4x * C4WFScale / 0x100);
C4WFYVal = (int16)(c4y * C4WFScale / 0x100);
}
void Cx4::C4DrawWireFrame() {
uint32 line = readl(0x1f80);
uint32 point1, point2;
int16 X1, Y1, Z1;
int16 X2, Y2, Z2;
uint8 Color;
for(int32 i = ram[0x0295]; i > 0; i--, line += 5) {
if(bus.read(line) == 0xff && bus.read(line + 1) == 0xff) {
int32 tmp = line - 5;
while(bus.read(tmp + 2) == 0xff && bus.read(tmp + 3) == 0xff && (tmp + 2) >= 0) { tmp -= 5; }
point1 = (read(0x1f82) << 16) | (bus.read(tmp + 2) << 8) | bus.read(tmp + 3);
} else {
point1 = (read(0x1f82) << 16) | (bus.read(line) << 8) | bus.read(line + 1);
}
point2 = (read(0x1f82) << 16) | (bus.read(line + 2) << 8) | bus.read(line + 3);
X1=(bus.read(point1 + 0) << 8) | bus.read(point1 + 1);
Y1=(bus.read(point1 + 2) << 8) | bus.read(point1 + 3);
Z1=(bus.read(point1 + 4) << 8) | bus.read(point1 + 5);
X2=(bus.read(point2 + 0) << 8) | bus.read(point2 + 1);
Y2=(bus.read(point2 + 2) << 8) | bus.read(point2 + 3);
Z2=(bus.read(point2 + 4) << 8) | bus.read(point2 + 5);
Color = bus.read(line + 4);
C4DrawLine(X1, Y1, Z1, X2, Y2, Z2, Color);
}
}
void Cx4::C4DrawLine(int32 X1, int32 Y1, int16 Z1, int32 X2, int32 Y2, int16 Z2, uint8 Color) {
//Transform coordinates
C4WFXVal = (int16)X1;
C4WFYVal = (int16)Y1;
C4WFZVal = Z1;
C4WFScale = read(0x1f90);
C4WFX2Val = read(0x1f86);
C4WFY2Val = read(0x1f87);
C4WFDist = read(0x1f88);
C4TransfWireFrame2();
X1 = (C4WFXVal + 48) << 8;
Y1 = (C4WFYVal + 48) << 8;
C4WFXVal = (int16)X2;
C4WFYVal = (int16)Y2;
C4WFZVal = Z2;
C4TransfWireFrame2();
X2 = (C4WFXVal + 48) << 8;
Y2 = (C4WFYVal + 48) << 8;
//Get line info
C4WFXVal = (int16)(X1 >> 8);
C4WFYVal = (int16)(Y1 >> 8);
C4WFX2Val = (int16)(X2 >> 8);
C4WFY2Val = (int16)(Y2 >> 8);
C4CalcWireFrame();
X2 = (int16)C4WFXVal;
Y2 = (int16)C4WFYVal;
//Render line
for(int32 i = C4WFDist ? C4WFDist : 1; i > 0; i--) {
if(X1 > 0xff && Y1 > 0xff && X1 < 0x6000 && Y1 < 0x6000) {
uint16 addr = (((Y1 >> 8) >> 3) << 8) - (((Y1 >> 8) >> 3) << 6) + (((X1 >> 8) >> 3) << 4) + ((Y1 >> 8) & 7) * 2;
uint8 bit = 0x80 >> ((X1 >> 8) & 7);
ram[addr + 0x300] &= ~bit;
ram[addr + 0x301] &= ~bit;
if(Color & 1) ram[addr + 0x300] |= bit;
if(Color & 2) ram[addr + 0x301] |= bit;
}
X1 += X2;
Y1 += Y2;
}
}
void Cx4::C4DoScaleRotate(int row_padding) {
int16 A, B, C, D;
//Calculate matrix
int32 XScale = readw(0x1f8f);
int32 YScale = readw(0x1f92);
if(XScale & 0x8000)XScale = 0x7fff;
if(YScale & 0x8000)YScale = 0x7fff;
if(readw(0x1f80) == 0) { //no rotation
A = (int16)XScale;
B = 0;
C = 0;
D = (int16)YScale;
} else if(readw(0x1f80) == 128) { //90 degree rotation
A = 0;
B = (int16)(-YScale);
C = (int16)XScale;
D = 0;
} else if(readw(0x1f80) == 256) { //180 degree rotation
A = (int16)(-XScale);
B = 0;
C = 0;
D = (int16)(-YScale);
} else if(readw(0x1f80) == 384) { //270 degree rotation
A = 0;
B = (int16)YScale;
C = (int16)(-XScale);
D = 0;
} else {
A = (int16) sar(CosTable[readw(0x1f80) & 0x1ff] * XScale, 15);
B = (int16)(-sar(SinTable[readw(0x1f80) & 0x1ff] * YScale, 15));
C = (int16) sar(SinTable[readw(0x1f80) & 0x1ff] * XScale, 15);
D = (int16) sar(CosTable[readw(0x1f80) & 0x1ff] * YScale, 15);
}
//Calculate Pixel Resolution
uint8 w = read(0x1f89) & ~7;
uint8 h = read(0x1f8c) & ~7;
//Clear the output RAM
memset(ram, 0, (w + row_padding / 4) * h / 2);
int32 Cx = (int16)readw(0x1f83);
int32 Cy = (int16)readw(0x1f86);
//Calculate start position (i.e. (Ox, Oy) = (0, 0))
//The low 12 bits are fractional, so (Cx<<12) gives us the Cx we want in
//the function. We do Cx*A etc normally because the matrix parameters
//already have the fractional parts.
int32 LineX = (Cx << 12) - Cx * A - Cx * B;
int32 LineY = (Cy << 12) - Cy * C - Cy * D;
//Start loop
uint32 X, Y;
uint8 byte;
int32 outidx = 0;
uint8 bit = 0x80;
for(int32 y = 0; y < h; y++) {
X = LineX;
Y = LineY;
for(int32 x = 0; x < w; x++) {
if((X >> 12) >= w || (Y >> 12) >= h) {
byte = 0;
} else {
uint32 addr = (Y >> 12) * w + (X >> 12);
byte = read(0x600 + (addr >> 1));
if(addr & 1) { byte >>= 4; }
}
//De-bitplanify
if(byte & 1) ram[outidx ] |= bit;
if(byte & 2) ram[outidx + 1] |= bit;
if(byte & 4) ram[outidx + 16] |= bit;
if(byte & 8) ram[outidx + 17] |= bit;
bit >>= 1;
if(!bit) {
bit = 0x80;
outidx += 32;
}
X += A; //Add 1 to output x => add an A and a C
Y += C;
}
outidx += 2 + row_padding;
if(outidx & 0x10) {
outidx &= ~0x10;
} else {
outidx -= w * 4 + row_padding;
}
LineX += B; //Add 1 to output y => add a B and a D
LineY += D;
}
}
#endif