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Rotate around the center of the object

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hasufell 2014-05-09 17:53:02 +02:00
parent 5bfce60f7e
commit 9658f92b58
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GPG Key ID: 220CD1C5BDEED020
1 changed files with 38 additions and 3 deletions
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41
src/gl_draw.c
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@ -52,6 +52,38 @@ static void draw_obj(uint32_t xrot, uint32_t yrot, uint32_t zrot);
static void draw_Planet_1(void);
static void draw_Planet_2(void);
static void gl_destroy(void);
static HE_vert *find_center(HE_obj const * const obj);
/**
* Find the center of an object and store the coordinates
* in a HE_vert struct.
*
* @param obj the object we want to find the center of
* @return newly allocated HE_vert with empty edge member
* and coordinates which represent the middle of the object
*/
static HE_vert *find_center(HE_obj const * const obj)
{
float x = 0,
y = 0,
z = 0;
uint32_t i;
HE_vert *newvert = malloc(sizeof(HE_vert));
for (i = 0; i < obj->vc; i++) {
x += obj->vertices[i].x;
y += obj->vertices[i].y;
z += obj->vertices[i].z;
}
newvert->x = x / i;
newvert->y = y / i;
newvert->z = z / i;
newvert->edge = NULL;
return newvert;
}
/**
* Call glVertex3f on all of the vertices of the object,
@ -84,6 +116,7 @@ static void draw_obj(uint32_t myxrot, uint32_t myyrot, uint32_t myzrot)
static uint32_t xrot = 0,
yrot = 0,
zrot = 0;
HE_vert *center_vert = find_center(obj);
xrot += myxrot;
yrot += myyrot;
@ -99,9 +132,9 @@ static void draw_obj(uint32_t myxrot, uint32_t myyrot, uint32_t myzrot)
glTranslatef(0.0f, 0.0f, SYSTEM_POS_Z_BACK);
/* pull into middle of universe */
glTranslatef(-obj->faces->edge->vert->x,
-obj->faces->edge->vert->y,
-obj->faces->edge->vert->z + SYSTEM_POS_Z);
glTranslatef(-center_vert->x,
-center_vert->y,
-center_vert->z + SYSTEM_POS_Z);
glBegin(GL_POLYGON);
glColor3f(0.0f, 1.0f, 0.0f);
@ -109,6 +142,8 @@ static void draw_obj(uint32_t myxrot, uint32_t myyrot, uint32_t myzrot)
glEnd();
glPopMatrix();
free(center_vert);
}
/**