shithub: cstory

Download patch

ref: e3549f87038b4880b0c05b25c7129067b542b5c9
parent: 293dbd4e03ab313af57abc17eabae3b0d47f581b
author: Clownacy <Clownacy@users.noreply.github.com>
date: Thu Feb 21 18:24:23 EST 2019 

Made Triangle.cpp ASM-accurate

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.


--- a/src/Triangle.cpp
+++ b/src/Triangle.cpp
@@ -8,19 +8,19 @@
 
 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 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;
-	
-	if (xa <= 0)
+	int16_t k;
+
+	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))
+				k = (x * 0x2000) / y;
+				while (k > gTan[a])
 					++a;
-				a += -0x80;
+				a = 0x40 - a;
 			}
 		}
-		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;
+			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 (ya <= 0)
+	else
 	{
-		if (-ya >= xa)
+		if (y > 0)
 		{
-			while (gTan[a] < (int16_t)((xa << 13) / -ya))
-				++a;
-			a -= 0x40;
+			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
 		{
-			while (gTan[a] < (int16_t)(-0x2000 * ya / xa))
-				++a;
-			a = -a;
+			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;
+			}
 		}
-	}
-	else if (xa <= ya)
-	{
-		while (gTan[a] < (int16_t)((xa << 13) / ya))
-			++a;
-		a = 0x40 - a;
-	}
-	else
-	{
-		while (gTan[a] < (int16_t)((ya << 13) / xa))
-			++a;
 	}
 	
 	return a;
--- a/src/Triangle.h
+++ b/src/Triangle.h
@@ -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);