#if 0
static const char sccsid[] = "@(#)b_draw.c 4.11 98/06/16 xlockmore";
#endif
/*-
* BUBBLE3D (C) 1998 Richard W.M. Jones.
* b_draw.c: This code creates new bubbles, manages them and controls
* them as they are drawn on the screen.
*/
#include "bubble3d.h"
typedef struct draw_context {
/* The list of bubbles currently on the screen. */
void **bubble_list;
int nr_bubbles;
/* When was the last time we created a new bubble? */
int bubble_count;
glb_data *d;
} draw_context;
void *
glb_draw_init(void)
{
draw_context *c;
GLfloat mat_specular[] =
{1, 1, 1, 1};
GLfloat mat_emission[] =
{0, 0, 0, 1};
GLfloat mat_shininess[] =
{100};
GLfloat ambient[] =
{0.5, 0.5, 0.5, 1.0};
GLfloat light_position[][4] =
{
{0, -1, 0, 0},
{1, 1, 0, 0},
{-1, 0, 1, 0}};
GLfloat light_diffuse[][4] =
{
{1, 1, 1, 1},
{1, 1, 1, 1},
{1, 1, 1, 1}};
GLfloat light_specular[][4] =
{
{1, 1, 1, 1},
{1, 1, 1, 1},
{1, 1, 1, 1}};
/* Initialize the context. */
c = (struct draw_context *) malloc(sizeof (struct draw_context));
if (c == 0)
return 0;
c->bubble_list = 0;
c->nr_bubbles = 0;
c->bubble_count = glb_config.create_bubbles_every;
/* Do some GL initialization. */
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, glb_config.bubble_colour);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, mat_specular);
glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, mat_emission);
glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, mat_shininess);
if (glb_config.transparent_p)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_LIGHT1);
glEnable(GL_LIGHT2);
if (glb_config.transparent_p)
glEnable(GL_BLEND);
else
glEnable(GL_DEPTH_TEST);
glEnable(GL_AUTO_NORMAL);
glEnable(GL_NORMALIZE);
if (glb_config.transparent_p)
glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambient);
glLightfv(GL_LIGHT0, GL_POSITION, light_position[0]);
glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse[0]);
glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular[0]);
glLightfv(GL_LIGHT1, GL_POSITION, light_position[1]);
glLightfv(GL_LIGHT1, GL_DIFFUSE, light_diffuse[1]);
glLightfv(GL_LIGHT1, GL_SPECULAR, light_specular[1]);
glLightfv(GL_LIGHT2, GL_POSITION, light_position[2]);
glLightfv(GL_LIGHT2, GL_DIFFUSE, light_diffuse[2]);
glLightfv(GL_LIGHT2, GL_SPECULAR, light_specular[2]);
c->d = glb_sphere_init();
return c;
}
static void
delete_bubble(draw_context * c, int j)
{
int i;
glb_bubble_delete(c->bubble_list[j]);
for (i = j; i < c->nr_bubbles - 1; ++i)
c->bubble_list[i] = c->bubble_list[i + 1];
c->nr_bubbles--;
}
void
glb_draw_end(void *cc)
{
draw_context *c = (draw_context *) cc;
int i;
for (i = 0; i < c->nr_bubbles; ++i) {
delete_bubble(c, i);
i--;
}
glb_sphere_end (c->d);
free(c->bubble_list);
free(c);
}
static int
create_new_bubbles(draw_context * c)
{
int n, i;
double r = glb_drand();
GLfloat size, speed, scale_incr, x, y, z;
void *b[4];
void **old_bubble_list;
/* How many bubbles to make? */
if (r < glb_config.p_bubble_group[0])
n = 1;
else if (r < glb_config.p_bubble_group[1])
n = 2;
else if (r < glb_config.p_bubble_group[2])
n = 3;
else
n = 4;
/* Initial position of top-most bubble in group. */
x = glb_drand() * 4 - 2;
y = glb_config.screen_bottom;
z = glb_drand() * 2 - 2;
/* What size? */
size = glb_config.min_size
+ glb_drand() * (glb_config.max_size - glb_config.min_size);
/* What speed? */
speed = glb_config.min_speed
+ glb_drand() * (glb_config.max_speed - glb_config.min_speed);
/* Work out the scaling increment. Bubbles should increase by scale_factor
* as they go from bottom to top of screen.
*/
scale_incr = (size * glb_config.scale_factor - size)
/ ((glb_config.screen_top - glb_config.screen_bottom) / speed);
/* Create the bubble(s). */
for (i = 0; i < n; ++i) {
if ((b[i] = glb_bubble_new(c->d, x, y, z, size, speed, scale_incr)) == 0) {
/* Out of memory - recover. */
i--;
while (i >= 0)
glb_bubble_delete(b[i]);
return 0;
}
/* Create the next bubble below the last bubble. */
y -= size * 3;
}
/* Add the bubbles to the list. */
c->nr_bubbles += n;
old_bubble_list = c->bubble_list;
if (c->bubble_list == 0) {
c->bubble_list = (void **) malloc(c->nr_bubbles * sizeof (void *));
} else {
c->bubble_list = (void **) realloc(c->bubble_list,
c->nr_bubbles * sizeof (void *));
}
if (c->bubble_list == 0) {
/* Out of memory - recover. */
for (i = 0; i < n; ++i)
glb_bubble_delete(b[i]);
c->bubble_list = old_bubble_list;
c->nr_bubbles -= n;
return 0;
}
for (i = 0; i < n; ++i)
c->bubble_list[c->nr_bubbles - i - 1] = b[i];
return 1;
}
void
glb_draw_step(void *cc)
{
draw_context *c = (draw_context *) cc;
int i;
/* Consider creating a new bubble or bubbles. */
if (c->nr_bubbles < glb_config.max_bubbles &&
c->bubble_count++ > glb_config.create_bubbles_every) {
if (create_new_bubbles(c))
c->bubble_count = 0;
}
/* Clear the display. */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
/* XXX Draw the background here ... */
/* Draw all the bubbles on the display. */
for (i = 0; i < c->nr_bubbles; ++i) {
void *b = c->bubble_list[i];
glb_bubble_step(b);
glb_bubble_draw(c->d, b);
/* Has the bubble reached the top of the screen? */
if (glb_bubble_get_y(b) >= glb_config.screen_top) {
delete_bubble(c, i);
i--;
}
}
}
