// intialize callback that gets called once for intialization
static void
_init_gl(Evas_Object *obj)
{
GLData *gld = evas_object_data_get(obj, "gld");
Evas_GL_API *gl = gld->glapi;
GLfloat vVertices[] = { 0.0f, 0.5f, 0.0f,
-0.5f, -0.5f, 0.0f,
0.5f, -0.5f, 0.0f };
if (!init_shaders(gld))
{
_printf("Error Initializing Shaders\n");
g_assert(FALSE);
}
gl->glGenBuffers(1, &gld->vbo);
gl->glBindBuffer(GL_ARRAY_BUFFER, gld->vbo);
gl->glBufferData(GL_ARRAY_BUFFER, 3 * 3 * 4, vVertices, GL_STATIC_DRAW);
}
/* Draw a gear wheel. You'll probably want to call this function when
* building a display list since we do a lot of trig here.
*
* Input: inner_radius - radius of hole at center
* outer_radius - radius at center of teeth
* width - width of gear
* teeth - number of teeth
* tooth_depth - depth of tooth
*/
static Gear *
make_gear(GLData *gld, GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
GLint teeth, GLfloat tooth_depth)
{
GLint i;
GLfloat r0, r1, r2;
GLfloat da;
GLfloat *v;
Gear *gear;
double s[5], c[5];
GLfloat normal[3];
const int tris_per_tooth = 20;
Evas_GL_API *gl = gld->glapi;
gear = (Gear*)malloc(sizeof(Gear));
if (gear == NULL)
return NULL;
r0 = inner_radius;
r1 = outer_radius - tooth_depth / 2.0;
r2 = outer_radius + tooth_depth / 2.0;
da = 2.0 * M_PI / teeth / 4.0;
gear->vertices = calloc(teeth * tris_per_tooth * 3 * 6,
sizeof *gear->vertices);
s[4] = 0;
c[4] = 1;
v = gear->vertices;
for (i = 0; i < teeth; i++)
{
s[0] = s[4];
c[0] = c[4];
s[1] = sin(i * 2.0 * M_PI / teeth + da);
c[1] = cos(i * 2.0 * M_PI / teeth + da);
s[2] = sin(i * 2.0 * M_PI / teeth + da * 2);
c[2] = cos(i * 2.0 * M_PI / teeth + da * 2);
s[3] = sin(i * 2.0 * M_PI / teeth + da * 3);
c[3] = cos(i * 2.0 * M_PI / teeth + da * 3);
s[4] = sin(i * 2.0 * M_PI / teeth + da * 4);
c[4] = cos(i * 2.0 * M_PI / teeth + da * 4);
normal[0] = 0.0;
normal[1] = 0.0;
normal[2] = 1.0;
v = vert(v, r2 * c[1], r2 * s[1], width * 0.5, normal);
v = vert(v, r2 * c[1], r2 * s[1], width * 0.5, normal);
v = vert(v, r2 * c[2], r2 * s[2], width * 0.5, normal);
v = vert(v, r1 * c[0], r1 * s[0], width * 0.5, normal);
v = vert(v, r1 * c[3], r1 * s[3], width * 0.5, normal);
v = vert(v, r0 * c[0], r0 * s[0], width * 0.5, normal);
v = vert(v, r1 * c[4], r1 * s[4], width * 0.5, normal);
v = vert(v, r0 * c[4], r0 * s[4], width * 0.5, normal);
v = vert(v, r0 * c[4], r0 * s[4], width * 0.5, normal);
v = vert(v, r0 * c[0], r0 * s[0], width * 0.5, normal);
v = vert(v, r0 * c[4], r0 * s[4], -width * 0.5, normal);
v = vert(v, r0 * c[0], r0 * s[0], -width * 0.5, normal);
normal[0] = 0.0;
normal[1] = 0.0;
normal[2] = -1.0;
v = vert(v, r0 * c[4], r0 * s[4], -width * 0.5, normal);
v = vert(v, r0 * c[4], r0 * s[4], -width * 0.5, normal);
v = vert(v, r1 * c[4], r1 * s[4], -width * 0.5, normal);
v = vert(v, r0 * c[0], r0 * s[0], -width * 0.5, normal);
v = vert(v, r1 * c[3], r1 * s[3], -width * 0.5, normal);
v = vert(v, r1 * c[0], r1 * s[0], -width * 0.5, normal);
v = vert(v, r2 * c[2], r2 * s[2], -width * 0.5, normal);
v = vert(v, r2 * c[1], r2 * s[1], -width * 0.5, normal);
v = vert(v, r1 * c[0], r1 * s[0], width * 0.5, normal);
v = vert(v, r1 * c[0], r1 * s[0], width * 0.5, normal);
v = vert(v, r1 * c[0], r1 * s[0], -width * 0.5, normal);
v = vert(v, r2 * c[1], r2 * s[1], width * 0.5, normal);
v = vert(v, r2 * c[1], r2 * s[1], -width * 0.5, normal);
v = vert(v, r2 * c[2], r2 * s[2], width * 0.5, normal);
v = vert(v, r2 * c[2], r2 * s[2], -width * 0.5, normal);
v = vert(v, r1 * c[3], r1 * s[3], width * 0.5, normal);
v = vert(v, r1 * c[3], r1 * s[3], -width * 0.5, normal);
v = vert(v, r1 * c[4], r1 * s[4], width * 0.5, normal);
v = vert(v, r1 * c[4], r1 * s[4], -width * 0.5, normal);
v = vert(v, r1 * c[4], r1 * s[4], -width * 0.5, normal);
}
gear->count = (v - gear->vertices) / 6;
gl->glGenBuffers(1, &gear->vbo);
gl->glBindBuffer(GL_ARRAY_BUFFER, gear->vbo);
gl->glBufferData(GL_ARRAY_BUFFER, gear->count * 6 * 4,
gear->vertices, GL_STATIC_DRAW);
return gear;
}
