diff --git a/src/game/bg.c b/src/game/bg.c
index 91f0d0006..c5ca95ec2 100644
--- a/src/game/bg.c
+++ b/src/game/bg.c
@@ -5322,7 +5322,7 @@ bool bgTestHitOnObj(struct coord *arg0, struct coord *arg1, struct coord *arg2,
 
 						if (!(arg0->y < min.y && arg1->y < min.y) && !(arg0->y > max.y && arg1->y > max.y)) {
 							if (bgTestLineIntersectsBbox(arg0, arg2, &min, &max)
-									&& func0002f560(point1, point2, point3, 0, arg0, arg1, arg2, &sp8c, &sp80)) {
+									&& func0002f560(point1, point2, point3, NULL, arg0, arg1, arg2, &sp8c, &sp80)) {
 								tmp = sp8c.x - arg0->x;
 								sqdist = tmp * tmp;
 
@@ -5609,7 +5609,7 @@ bool bgTestHitOnChr(struct model *model, struct coord *arg1, struct coord *arg2,
 
 						if (!(arg1->y < min.y && arg2->y < min.y) && !(arg1->y > max.y && arg2->y > max.y)) {
 							if (bgTestLineIntersectsBbox(arg1, arg3, &min, &max)
-									&& func0002f560(point1, point2, point3, 0, arg1, arg2, arg3, &sp84, &sp78)) {
+									&& func0002f560(point1, point2, point3, NULL, arg1, arg2, arg3, &sp84, &sp78)) {
 								tmp = sp84.x - arg1->x;
 								sqdist = tmp * tmp;
 
@@ -5813,7 +5813,7 @@ bool bgTestHitInVtxBatch(struct coord *arg0, struct coord *arg1, struct coord *a
 
 								if (!(arg0->y > max.y && arg1->y > max.y)) {
 									if (bgTestLineIntersectsBbox(arg0, arg2, &min, &max)
-											&& func0002f560(point1, point2, point3, 0, arg0, arg1, arg2, &spb0, &spa4)) {
+											&& func0002f560(point1, point2, point3, NULL, arg0, arg1, arg2, &spb0, &spa4)) {
 										f32 tmp;
 
 										tmp = spb0.x - arg0->x;
diff --git a/src/game/dlights.c b/src/game/dlights.c
index 499f1637d..e7cc92e55 100644
--- a/src/game/dlights.c
+++ b/src/game/dlights.c
@@ -499,8 +499,8 @@ bool lightsHandleHit(struct coord *gunpos, struct coord *hitpos, s32 roomnum)
 
 	for (i = 0; i < g_Rooms[roomnum].numlights; i++) {
 		if (light->healthy && light->vulnerable) {
-			if (func0002f490(&light->bbox[0], &light->bbox[1], &light->bbox[3], 0, &spa4, &sp98, &sp8c, 0, 0)
-					|| func0002f490(&light->bbox[1], &light->bbox[2], &light->bbox[3], 0, &spa4, &sp98, &sp8c, 0, 0)) {
+			if (func0002f490(&light->bbox[0], &light->bbox[1], &light->bbox[3], NULL, &spa4, &sp98, &sp8c, 0, 0)
+					|| func0002f490(&light->bbox[1], &light->bbox[2], &light->bbox[3], NULL, &spa4, &sp98, &sp8c, 0, 0)) {
 				struct coord soundpos;
 
 				soundpos.x = light->bbox[0].x;
diff --git a/src/include/lib/lib_2f490.h b/src/include/lib/lib_2f490.h
index 31fbd2d1b..56ee9ab4c 100644
--- a/src/include/lib/lib_2f490.h
+++ b/src/include/lib/lib_2f490.h
@@ -4,7 +4,7 @@
 #include "data.h"
 #include "types.h"
 
-bool func0002f490(struct vec3s16 *arg0, struct vec3s16 *arg1, struct vec3s16 *arg2, s32 arg3, struct coord *arg4, struct coord *arg5, struct coord *arg6, struct coord *arg7, struct coord *arg8);
-bool func0002f560(struct coord *arg0, struct coord *arg1, struct coord *arg2, s32 arg3, struct coord *arg4, struct coord *arg5, struct coord *arg6, struct coord *arg7, struct coord *arg8);
+bool func0002f490(struct vec3s16 *arg0, struct vec3s16 *arg1, struct vec3s16 *arg2, struct coord *arg3, struct coord *arg4, struct coord *arg5, struct coord *arg6, struct coord *arg7, struct coord *arg8);
+bool func0002f560(struct coord *arg0, struct coord *arg1, struct coord *arg2, struct coord *arg3, struct coord *arg4, struct coord *arg5, struct coord *arg6, struct coord *arg7, struct coord *arg8);
 
 #endif
diff --git a/src/lib/collision.c b/src/lib/collision.c
index 6631869cf..ae8b28ea8 100644
--- a/src/lib/collision.c
+++ b/src/lib/collision.c
@@ -2710,7 +2710,7 @@ bool cd0002aac0IntTile(struct coord *arg0, struct coord *arg1, struct coord *arg
 		if (func0002f490((struct vec3s16 *)&tile->vertices[0][0],
 					(struct vec3s16 *)&tile->vertices[i - 1][0],
 					(struct vec3s16 *)&tile->vertices[i][0],
-					0, arg0, arg1, arg2, arg4, arg5)) {
+					NULL, arg0, arg1, arg2, arg4, arg5)) {
 			return true;
 		}
 	}
@@ -2725,7 +2725,7 @@ bool cd0002ab98FltTile(struct coord *arg0, struct coord *arg1, struct coord *arg
 
 	for (i = 2; i < numvertices; i++) {
 		if (func0002f560(&tile->vertices[0], &tile->vertices[i - 1], &tile->vertices[i],
-					0, arg0, arg1, arg2, arg4, arg5)) {
+					NULL, arg0, arg1, arg2, arg4, arg5)) {
 			return true;
 		}
 	}
diff --git a/src/lib/lib_2f490_c.c b/src/lib/lib_2f490_c.c
new file mode 100644
index 000000000..079fced21
--- /dev/null
+++ b/src/lib/lib_2f490_c.c
@@ -0,0 +1,215 @@
+#include <ultra64.h>
+#include "constants.h"
+#include "bss.h"
+#include "data.h"
+#include "lib/mtx.h"
+#include "types.h"
+
+static bool implementation(
+		f32 f0, f32 f1, f32 f2,
+		f32 f12, f32 f13, f32 f14,
+		f32 f15, f32 f16, f32 f17,
+		struct coord *arg3, struct coord *t0, struct coord *t1,
+		struct coord *t2, struct coord *t3, struct coord *t4)
+{
+	f32 f3;
+	f32 f4;
+	f32 f5;
+	f32 f6;
+	f32 f7;
+	f32 f8;
+	f32 f9;
+	f32 f10;
+	f32 f11;
+	f32 f18;
+	f32 f19;
+	f32 f20;
+	f32 f21;
+	f32 f22;
+	f32 f23;
+	f32 f24;
+	f32 f25;
+	f32 f26;
+	f32 f27;
+	f32 f28;
+
+	f3 = f12 - f0;
+	f4 = f13 - f1;
+	f5 = f14 - f2;
+	f6 = f15 - f12;
+	f7 = f16 - f13;
+	f8 = f17 - f14;
+	f9 = f15 - f0;
+	f10 = f16 - f1;
+	f11 = f17 - f2;
+
+	if (arg3 != NULL) {
+		f0 += arg3->x;
+		f1 += arg3->y;
+		f2 += arg3->z;
+	}
+
+	f12 = f4 * f8;
+	f13 = f7 * f5;
+	f14 = f5 * f6;
+	f12 = f12 - f13;
+	f15 = f8 * f3;
+	f16 = f3 * f7;
+	f13 = f14 - f15;
+	f14 = f6 * f4;
+	f14 = f16 - f14;
+	f15 = f12 * f0;
+	f16 = f13 * f1;
+	f17 = f14 * f2;
+	f15 = f15 + f16;
+	f15 = f15 + f17;
+
+	f16 = t2->x;
+	f17 = t2->y;
+	f18 = t2->z;
+
+	f19 = f12 * f16;
+	f20 = f13 * f17;
+	f19 = f19 + f20;
+	f20 = f14 * f18;
+	f19 = f19 + f20;
+
+	if (f19 == 0.0f) {
+		return false;
+	}
+
+	f20 = t1->x;
+	f21 = t1->y;
+	f22 = t1->z;
+	f23 = f12 * f20;
+	f24 = f13 * f21;
+	f23 = f15 - f23;
+	f25 = f14 * f22;
+	f23 = f23 - f24;
+	f23 = f23 - f25;
+	f19 = f23 / f19;
+	f23 = f19 * f16;
+	f24 = f19 * f17;
+	f23 = f20 + f23;
+	f25 = f19 * f18;
+	f24 = f21 + f24;
+	f25 = f22 + f25;
+	f26 = f23 - f20;
+	f26 = f16 * f26;
+	f27 = f24 - f21;
+	f27 = f17 * f27;
+	f28 = f25 - f22;
+	f26 = f26 + f27;
+	f27 = f18 * f28;
+	f26 = f26 + f27;
+
+	if (f26 > 0) {
+		return false;
+	}
+
+	f20 = t0->x;
+	f21 = t0->y;
+	f22 = t0->z;
+	f26 = f23 - f20;
+	f26 = f16 * f26;
+	f27 = f24 - f21;
+	f27 = f17 * f27;
+	f28 = f25 - f22;
+	f26 = f26 + f27;
+	f27 = f18 * f28;
+	f26 = f26 + f27;
+
+	if (f26 < 0) {
+		return false;
+	}
+
+	f0 = f23 - f0;
+	f1 = f24 - f1;
+	f2 = f25 - f2;
+	f26 = f6 * f4;
+	f27 = f3 * f7;
+	f26 = f26 - f27;
+
+	if (f26 != 0.0f) {
+		f27 = f0 * f4;
+		f28 = f1 * f3;
+	} else {
+		f26 = f7 * f5;
+		f27 = f4 * f8;
+		f26 = f26 - f27;
+
+		if (f26 != 0.0f) {
+			f27 = f1 * f5;
+			f28 = f2 * f4;
+		} else {
+			f26 = f8 * f3;
+			f27 = f5 * f6;
+			f26 = f26 - f27;
+			f27 = f2 * f3;
+			f28 = f0 * f5;
+		}
+	}
+
+	f27 = f27 - f28;
+	f27 = f27 / f26;
+
+	if (f27 < 0.0f) {
+		return false;
+	}
+
+	if (f3 != 0.0f) {
+		f28 = f27 * f9;
+		f28 = f0 - f28;
+		f28 = f28 / f3;
+	} else if (f4 != 0.0f) {
+		f28 = f27 * f10;
+		f28 = f1 - f28;
+		f28 = f28 / f4;
+	} else {
+		f28 = f27 * f11;
+		f28 = f2 - f28;
+		f28 = f28 / f5;
+	}
+
+	if (f28 >= 0.0f && f28 + f27 <= 1.0f) {
+		if (t3 != NULL) {
+			t3->x = f23;
+			t3->y = f24;
+			t3->z = f25;
+		}
+
+		if (t4 != NULL) {
+			t4->x = f12;
+			t4->y = f13;
+			t4->z = f14;
+		}
+
+		return true;
+	}
+
+	return false;
+}
+
+bool func0002f490(struct vec3s16 *arg0, struct vec3s16 *arg1, struct vec3s16 *arg2,
+		struct coord *arg3, struct coord *t0, struct coord *t1,
+		struct coord *t2, struct coord *t3, struct coord *t4)
+{
+	// Casting arg0/arg1/arg2 properties from s16 to float
+	return implementation(
+			arg0->x, arg0->y, arg0->z,
+			arg1->x, arg1->y, arg1->z,
+			arg2->x, arg2->y, arg2->z,
+			arg3, t0, t1, t2, t3, t4);
+}
+
+bool func0002f560(struct coord *arg0, struct coord *arg1, struct coord *arg2,
+		struct coord *arg3, struct coord *t0, struct coord *t1,
+		struct coord *t2, struct coord *t3, struct coord *t4)
+{
+	// No casting (arg0/arg1/arg2 properties are already floats)
+	return implementation(
+			arg0->x, arg0->y, arg0->z,
+			arg1->x, arg1->y, arg1->z,
+			arg2->x, arg2->y, arg2->z,
+			arg3, t0, t1, t2, t3, t4);
+}