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Made Triangle.cpp ASM-accurate

Browse source 
It's really starting to look more and more like Pixel really did write
in C90... just look at the declarations I have to shove at the start of
the functions.
This commit is contained in:
Clownacy 2019-02-21 23:24:23 +00:00
parent 293dbd4e03
commit e3549f8703
2 changed files with 70 additions and 51 deletions
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123
src/Triangle.cpp
View file

@ -8,19 +8,19 @@ int16_t gTan[0x21];
void InitTriangleTable()
{
int i;
//Sine
for (int i = 0; i < 0x100; ++i )
for (i = 0; i < 0x100; ++i)
{
float v0 = i * 6.2831998 / 256.0;
gSin[i] = (int)(sinf(v0) * 512.0);
gSin[i] = (int)(sin(i * 6.2831998 / 256.0) * 512.0);
}
//Tangent
for (int i = 0; i < 0x21; ++i )
for (i = 0; i < 0x21; ++i)
{
float a = i * 6.2831855 / 256.0;
float v2 = sinf(a);
float b = v2 / cosf(a);
float b = sinf(a) / cosf(a);
gTan[i] = (int16_t)(b * 8192.0);
}
}
@ -32,70 +32,89 @@ int GetSin(uint8_t deg)
int GetCos(uint8_t deg)
{
return gSin[(uint8_t)(deg + 0x40)];
deg += 0x40;
return gSin[deg];
}
int GetArktan(int x, int y)
uint8_t GetArktan(int x, int y)
{
int xa = -x;
int ya = -y;
x *= -1;
y *= -1;
uint8_t a = 0;
int16_t k;
if (xa <= 0)
if (x > 0)
{
if (ya <= 0)
if (y > 0)
{
if (-xa <= -ya)
if (x > y)
{
while (gTan[a] < (int16_t)(-0x2000 * xa / -ya))
k = (y * 0x2000) / x;
while (k > gTan[a])
++a;
a = -0x40 - a;
}
else
{
while (gTan[a] < (int16_t)(-0x2000 * ya / -xa))
++a;
a += -0x80;
}
}
else if (-xa <= ya)
{
while (gTan[a] < (int16_t)(-0x2000 * xa / ya))
++a;
a += 0x40;
}
else
{
while (gTan[a] < (int16_t)((ya << 13) / -xa))
++a;
a = -0x80 - a;
}
}
else if (ya <= 0)
{
if (-ya >= xa)
{
while (gTan[a] < (int16_t)((xa << 13) / -ya))
++a;
a -= 0x40;
}
else
{
while (gTan[a] < (int16_t)(-0x2000 * ya / xa))
++a;
a = -a;
}
}
else if (xa <= ya)
{
while (gTan[a] < (int16_t)((xa << 13) / ya))
k = (x * 0x2000) / y;
while (k > gTan[a])
++a;
a = 0x40 - a;
}
}
else
{
while (gTan[a] < (int16_t)((ya << 13) / xa))
if (-y < x)
{
k = (-y * 0x2000) / x;
while (k > gTan[a])
++a;
a = 0x100 - a;
}
else
{
k = (x * 0x2000) / -y;
while (k > gTan[a])
++a;
a = 0x100 - 0x40 + a;
}
}
}
else
{
if (y > 0)
{
if (-x > y)
{
k = (y * 0x2000) / -x;
while (k > gTan[a])
++a;
a = 0x80 - a;
}
else
{
k = (-x * 0x2000) / y;
while (k > gTan[a])
++a;
a = 0x40 + a;
}
}
else
{
if (-x > -y)
{
k = (-y * 0x2000) / -x;
while (k > gTan[a])
++a;
a = 0x80 + a;
}
else
{
k = (-x * 0x2000) / -y;
while (k > gTan[a])
++a;
a = 0x100 - 0x40 - a;
}
}
}
return a;

2
src/Triangle.h
View file

@ -5,4 +5,4 @@
void InitTriangleTable();
int GetSin(uint8_t deg);
int GetCos(uint8_t deg);
int GetArktan(int x, int y);
uint8_t GetArktan(int x, int y);