From 53f68bb7b0dce309723675c4b97f726a469031c0 Mon Sep 17 00:00:00 2001
From: Joel Stålnacke <joel@saker.fi>
Date: Sun, 13 Oct 2024 15:09:24 +0300
Subject: Added more math functions and sanity checks

No +/-Inf or NaN in my vectors please :)
---
 lib/build.sh |  2 +-
 lib/types.h  |  2 ++
 lib/vec2.c   | 21 +++++++++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

(limited to 'lib')

diff --git a/lib/build.sh b/lib/build.sh
index 725c237..f305939 100755
--- a/lib/build.sh
+++ b/lib/build.sh
@@ -7,7 +7,7 @@ fail() {
 
 CC=cc
 CFLAGS="-std=c99 -Wall -Wextra -Wpedantic -D_POSIX_C_SOURCE=200809L"
-LDFLAGS="-fPIC"
+LDFLAGS="-fPIC -lm"
 SOURCES="test.c vec2.c world.c log.c"
 output="build"
 
diff --git a/lib/types.h b/lib/types.h
index 0619c8a..8618df9 100644
--- a/lib/types.h
+++ b/lib/types.h
@@ -8,3 +8,5 @@ vec2 dp_vec2_add(vec2, vec2);
 vec2 dp_vec2_sub(vec2, vec2);
 vec2 dp_vec2_mul(vec2, float scalar);
 vec2 dp_vec2_dot(vec2, vec2);
+float dp_vec2_length(vec2);
+vec2 dp_vec2_normal(vec2);
diff --git a/lib/vec2.c b/lib/vec2.c
index b417e9c..d795d50 100644
--- a/lib/vec2.c
+++ b/lib/vec2.c
@@ -1,9 +1,16 @@
+#include <assert.h>
+#include <math.h>
+
 #include "types.h"
 
 vec2
 dp_vec2_new(float x, float y)
 {
 	vec2 new;
+	
+	assert(isfinite(x));
+	assert(isfinite(y));
+
 	new.x = x;
 	new.y = y;
 	return new;
@@ -44,3 +51,17 @@ dp_vec2_dot(vec2 a, vec2 b)
 	dot.y = a.y * b.y;
 	return dot;
 }
+
+float
+dp_vec2_length(vec2 v)
+{
+	return sqrtf(powf(v.x, 2.f) + powf(v.y, 2.f));
+}
+
+vec2
+dp_vec2_normal(vec2 v)
+{
+	float a;
+	a = 1.f / dp_vec2_length(v);
+	return dp_vec2_mul(v, a);
+}
-- 
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