Add vec_math module

src/Makefile

@@ -15,8 +15,8 @@ CFLAGS += -O0 -g3
 endif
 
 TARGET = drow-engine
-HEADERS = err.h parser.h types.h print.h filereader.h gl_draw.h
-OBJECTS = main.o parser.o print.o filereader.o gl_draw.o
+HEADERS = err.h parser.h types.h print.h filereader.h gl_draw.h vec_math.h
+OBJECTS = main.o parser.o print.o filereader.o gl_draw.o vec_math.c
 INCS = -I.
 
 CFLAGS += $(shell $(PKG_CONFIG) --cflags gl glu glib-2.0)

src/print.c

@@ -92,3 +92,19 @@ void print_plain_faces(FACE face, uint32_t fc)
 	}
 	printf("\n");
 }
+
+/**
+ * Print all coordinates of a vector.
+ *
+ * @param the vector we want to print
+ */
+void print_vector(vector *vec)
+{
+	printf("vector:\n"
+			"x %f\n"
+			"y %f\n"
+			"z %f\n\n",
+			vec->x,
+			vec->y,
+			vec->z);
+}

src/print.h

@@ -27,6 +27,7 @@ void print_edges(HE_obj *obj);
 void print_vertices(HE_obj *obj);
 void print_faces(HE_obj *obj);
 void print_plain_faces(FACE face, uint32_t fc);
+void print_vector(vector *vec);
 
 
 #endif /* _DROW_ENGINE_PRINT_H */

src/types.h

@@ -30,11 +30,21 @@
 
 typedef uint32_t** FACE;
 
+typedef struct vector vector;
 typedef struct HE_edge HE_edge;
 typedef struct HE_vert HE_vert;
 typedef struct HE_face HE_face;
 typedef struct HE_obj HE_obj;
 
+/**
+ * Represents a vector with x, y, z coordinates.
+ */
+struct vector {
+	float x;
+	float y;
+	float z;
+};
+
 /**
  * Represents a half-edge.
  */

src/vec_math.c

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2011-2014 hasufell
+ *
+ * This file is part of a hasufell project.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation version 2 of the License only.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "err.h"
+#include "types.h"
+
+#include <stdbool.h>
+#include <stdlib.h>
+
+
+/**
+ * Calculate the vector product of a and b
+ * and store it in c.
+ *
+ * @param a vector
+ * @param b vector
+ * @param c vector [out]
+ * @return true/false for success/failure
+ */
+bool vector_product(vector *a, vector *b, vector *c)
+{
+	if (!a || !b)
+		return false;
+
+	c->x = a->y * b->z - a->z * b->y;
+	c->y = a->z * b->x - a->x * b->z;
+	c->z = a->x * b->y - a->y * b->x;
+
+	return true;
+}

src/vec_math.h

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2011-2014 hasufell
+ *
+ * This file is part of a hasufell project.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation version 2 of the License only.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _DROW_ENGINE_VEC_MATH_H
+#define _DROW_ENGINE_VEC_MATH_H
+
+
+#include "types.h"
+
+#include <stdbool.h>
+
+
+bool vector_product(vector *a, vector *b, vector *c);
+
+
+#endif /* _DROW_ENGINE_VEC_MATH_H */