add rotation parsing

1 files changed, 88 insertions, 0 deletions

diff --git a/src/transform.c b/src/transform.c
index 7c50a5e..6e4db56 100644
--- a/src/transform.c
+++ b/src/transform.c
@@ -1,11 +1,15 @@
 #include <stdlib.h>
 #include <string.h>
+#include <math.h>
 
 #include <kalmia.h>
 #include <ezxml.h>
 #include "transform.h"
 
 
+#define TWO_PI 6.2831853071796f
+
+
 int kai_parse_matrix(ka_matrix_t *m, ezxml_t tag)
 {
 	if (strcmp("matrix", ezxml_name(tag)) != 0)
@@ -21,3 +25,87 @@ int kai_parse_matrix(ka_matrix_t *m, ezxml_t tag)
 	
 	return 0;
 }
+
+
+int kai_parse_rotate(ka_matrix_t *m, ezxml_t tag)
+{
+	if (strcmp("rotate", ezxml_name(tag)) != 0)
+		return -1;
+	
+	char *str = ezxml_txt(tag);
+	char *end;
+	int i;
+	double rot[4];
+	for (i=0; i<4; i++) {
+		rot[i] = strtod(str, &end);
+		str = end;
+	}
+
+	double x, y, z, angle;
+	x = rot[0];
+	y = rot[1];
+	z = rot[2];
+	angle = rot[3];
+
+	/* normalize length */
+	double axis_len = (x*x) + (y*y) + (z*z);
+	axis_len = sqrt(axis_len);
+	x /= axis_len;
+	y /= axis_len;
+	z /= axis_len;
+
+	/* convert angle to radians */
+	angle *= TWO_PI / 360;
+
+	/* compute rotation matrix entries */
+	double co = cos(angle);
+	double unco = 1 - co;
+	double si = sin(angle);
+
+	(*m)[0] = (x*x*unco) + co;
+	(*m)[1] = (x*y*unco) - (z*si);
+	(*m)[2] = (x*z*unco) + (y*si);
+	(*m)[3] = 0.0f;
+	(*m)[4] = (y*x*unco) + (z*si);
+	(*m)[5] = (y*y*unco) + co;
+	(*m)[6] = (y*z*unco) - (x*si);
+	(*m)[7] = 0.0f;
+	(*m)[8] = (z*x*unco) - (y*si);
+	(*m)[9] = (z*y*unco) + (x*si);
+	(*m)[10] = (z*z*unco) + co;
+	(*m)[11] = 0.0f;
+	(*m)[12] = 0.0f;
+	(*m)[13] = 0.0f;
+	(*m)[14] = 0.0f;
+	(*m)[15] = 1.0f;
+
+	return 0;
+}
+
+
+int kai_parse_translate(ka_matrix_t *m, ezxml_t tag)
+{
+	if (strcmp("translate", ezxml_name(tag)) != 0)
+		return -1;
+
+	char *str = ezxml_txt(tag);
+	char *end;
+	int i;
+	double move[3];
+	for (i=0; i<3; i++) {
+		move[i] = strtod(str, &end);
+		str = end;
+	}
+
+	memset(*m, 0, sizeof(ka_matrix_t));
+
+	(*m)[0] = 1.0f;
+	(*m)[3] = move[0];
+	(*m)[5] = 1.0f;
+	(*m)[7] = move[1];
+	(*m)[10] = 1.0f;
+	(*m)[11] = move[2];
+	(*m)[15] = 1.0f;
+	
+	return 0;
+}