// 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; }