add maths library and print_dbl

4 files changed, 78 insertions, 8 deletions

diff --git a/stage3/font.c b/stage3/font.c
index f47c9c9..3bbba86 100644
--- a/stage3/font.c
+++ b/stage3/font.c
@@ -3,6 +3,8 @@
 #include "gfx.h"
 #include "heap.h"
 #include "memory.h"
+#include "math.h"
+
 #include "font_builtin.c"
 
 // important: must be a multiple of 2, else code won't work
@@ -197,3 +199,15 @@ void print_hex(u64 x)
 	print_num(x, 16);
 }
 
+void print_dbl(double d, u8 points)
+{
+	if (d < 0) {
+		print_char('-');
+		d = -d;
+	}
+
+	long i = d;
+	print_dec(i);
+	print_char('.');
+	print_num_pad((d - (double) i) * (double) ipow(10, points), 10, points, '0');
+}
diff --git a/stage3/font.h b/stage3/font.h
index 154b58e..03772db 100644
--- a/stage3/font.h
+++ b/stage3/font.h
@@ -16,5 +16,6 @@ void print_dec(u64 x);
 void print_hex(u64 x);
 void print_num(u64 x, u8 base);
 void print_num_pad(u64 x, u8 base, u8 pad_len, char pad_char);
+void print_dbl(double d, u8 points);
 
 #endif
diff --git a/stage3/math.h b/stage3/math.h
new file mode 100644
index 0000000..6f7ae58
--- /dev/null
+++ b/stage3/math.h
@@ -0,0 +1,62 @@
+#ifndef MATH_H
+#define MATH_H
+
+// for now, stuff will be added in this file as it is needed
+
+#define PI 3.14159265358979323846
+
+/*double get_pi()
+{
+	double pi;
+	asm("fldpi; fstpl %0":"=m"(pi));
+	return pi;
+}*/
+
+static inline double sin(double x)
+{
+	asm("fldl %1; fsin; fstpl %0":"=m"(x):"m"(x));
+	return x;
+}
+
+static inline double rad(double x)
+{
+	return PI / 180.0 * x;
+}
+
+static inline double deg(double x)
+{
+	return 180.0 / PI * x;
+}
+
+static inline double fabs(double x)
+{
+	asm("fldl %1; fabs; fstpl %0":"=m"(x):"m"(x));
+	return x;
+}
+
+static inline double atan2(double x, double y)
+{
+	asm("fldl %1; fldl %2; fpatan; fstpl %0":"=m"(x):"m"(x),"m"(y));
+	return x;
+}
+
+static inline double sqrt(double x)
+{
+	asm("fldl %0; fsqrt; fstpl %0":"=m"(x):"m"(x));
+	return x;
+}
+
+static inline double acos(double x)
+{
+	return atan2(sqrt(1-x*x),x);
+}
+
+static inline long ipow(long b, unsigned long exp)
+{
+	long x = 1;
+	for (unsigned long i = 0; i < exp; i++)
+		x *= b;
+	return x;
+}
+
+#endif
diff --git a/stage3/shell.c b/stage3/shell.c
index 0f56a04..055c296 100644
--- a/stage3/shell.c
+++ b/stage3/shell.c
@@ -7,6 +7,7 @@
 #include "pci.h"
 #include "memory.h"
 #include "io.h"
+#include "math.h"
 
 static void cmd_echo(str arg)
 {
@@ -177,14 +178,6 @@ static void cmd_uname(str arg)
 	print(S("\n"));
 }
 
-static u64 ipow(u64 b, u64 exp)
-{
-	u64 x = 1;
-	for (u64 i = 0; i < exp; i++)
-		x *= b;
-	return x;
-}
-
 static void print_bytes(usize bytes)
 {
 	static char fmt[] = { ' ', 'K', 'M', 'G', 'T' };