git.hungrycats.org Git - xscreensaver/blob - hacks/glx/b_draw.c

   1 #if 0
   2 static const char sccsid[] = "@(#)b_draw.c  4.11 98/06/16 xlockmore";
   3 #endif
   4
   5 /*-
   6  * BUBBLE3D (C) 1998 Richard W.M. Jones.
   7  * b_draw.c: This code creates new bubbles, manages them and controls
   8  * them as they are drawn on the screen.
   9  */
  10
  11 #include "bubble3d.h"
  12
  13 typedef struct draw_context {
  14         /* The list of bubbles currently on the screen. */
  15         void      **bubble_list;
  16         int         nr_bubbles;
  17
  18         /* When was the last time we created a new bubble? */
  19         int         bubble_count;
  20 } draw_context;
  21
  22 void       *
  23 glb_draw_init(void)
  24 {
  25         draw_context *c;
  26
  27         GLfloat     mat_specular[] =
  28         {1, 1, 1, 1};
  29         GLfloat     mat_emission[] =
  30         {0, 0, 0, 1};
  31         GLfloat     mat_shininess[] =
  32         {100};
  33         GLfloat     ambient[] =
  34         {0.5, 0.5, 0.5, 1.0};
  35         GLfloat     light_position[][4] =
  36         {
  37                 {0, -1, 0, 0},
  38                 {1, 1, 0, 0},
  39                 {-1, 0, 1, 0}};
  40         GLfloat     light_diffuse[][4] =
  41         {
  42                 {1, 1, 1, 1},
  43                 {1, 1, 1, 1},
  44                 {1, 1, 1, 1}};
  45         GLfloat     light_specular[][4] =
  46         {
  47                 {1, 1, 1, 1},
  48                 {1, 1, 1, 1},
  49                 {1, 1, 1, 1}};
  50
  51         /* Initialize the context. */
  52         c = (struct draw_context *) malloc(sizeof (struct draw_context));
  53
  54         if (c == 0)
  55                 return 0;
  56         c->bubble_list = 0;
  57         c->nr_bubbles = 0;
  58         c->bubble_count = glb_config.create_bubbles_every;
  59
  60         /* Do some GL initialization. */
  61         glClearColor(glb_config.bg_colour[0],
  62                      glb_config.bg_colour[1],
  63                      glb_config.bg_colour[2],
  64                      glb_config.bg_colour[3]);
  65 #if 0
  66         glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, glb_config.bubble_colour);
  67 #else
  68         {
  69                 /*
  70                  * E. Lassauge - 98/06/29
  71                  * Yeahh, cool ! Now that I know how to have random colors I
  72                  * patch this pretty beautiful mode too !!
  73                  */
  74                 GLfloat     fred, fgreen, fblue;
  75                 GLfloat     params[4];
  76
  77                 fred = ((float) (NRAND(100)) / 100.0);
  78                 fgreen = ((float) (NRAND(100)) / 100.0);
  79                 /* I keep more blue */
  80                 fblue = ((float) (NRAND(50)) / 100.0) + 0.50;
  81
  82                 params[0] = fred;
  83                 params[1] = fgreen;
  84                 params[2] = fblue;
  85                 /* For the moment don't play with ALPHA channel */
  86                 params[3] = glb_config.bubble_colour[3];
  87                 glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, params);
  88         }
  89 #endif
  90         glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, mat_specular);
  91         glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, mat_emission);
  92         glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, mat_shininess);
  93
  94 #if GLB_USE_BLENDING
  95         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  96 #endif
  97
  98         glEnable(GL_LIGHTING);
  99         glEnable(GL_LIGHT0);
 100         glEnable(GL_LIGHT1);
 101         glEnable(GL_LIGHT2);
 102 #if GLB_USE_BLENDING
 103         glEnable(GL_BLEND);
 104 #else
 105         glEnable(GL_DEPTH_TEST);
 106 #endif
 107         glEnable(GL_AUTO_NORMAL);
 108         glEnable(GL_NORMALIZE);
 109
 110 #if GLB_USE_BLENDING
 111         glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
 112 #endif
 113         glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambient);
 114         glLightfv(GL_LIGHT0, GL_POSITION, light_position[0]);
 115         glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse[0]);
 116         glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular[0]);
 117         glLightfv(GL_LIGHT1, GL_POSITION, light_position[1]);
 118         glLightfv(GL_LIGHT1, GL_DIFFUSE, light_diffuse[1]);
 119         glLightfv(GL_LIGHT1, GL_SPECULAR, light_specular[1]);
 120         glLightfv(GL_LIGHT2, GL_POSITION, light_position[2]);
 121         glLightfv(GL_LIGHT2, GL_DIFFUSE, light_diffuse[2]);
 122         glLightfv(GL_LIGHT2, GL_SPECULAR, light_specular[2]);
 123
 124         return c;
 125 }
 126
 127 static void
 128 delete_bubble(draw_context * c, int j)
 129 {
 130         int         i;
 131
 132         glb_bubble_delete(c->bubble_list[j]);
 133
 134         for (i = j; i < c->nr_bubbles - 1; ++i)
 135                 c->bubble_list[i] = c->bubble_list[i + 1];
 136
 137         c->nr_bubbles--;
 138 }
 139
 140 void
 141 glb_draw_end(void *cc)
 142 {
 143         draw_context *c = (draw_context *) cc;
 144         int         i;
 145
 146         for (i = 0; i < c->nr_bubbles; ++i) {
 147                 delete_bubble(c, i);
 148                 i--;
 149         }
 150         (void) free((void *) c->bubble_list);
 151         (void) free((void *) c);
 152 }
 153
 154 static int
 155 create_new_bubbles(draw_context * c)
 156 {
 157         int         n, i;
 158         double      r = glb_drand();
 159         GLfloat     size, speed, scale_incr, x, y, z;
 160         void       *b[4];
 161         void      **old_bubble_list;
 162
 163         /* How many bubbles to make? */
 164         if (r < glb_config.p_bubble_group[0])
 165                 n = 1;
 166         else if (r < glb_config.p_bubble_group[1])
 167                 n = 2;
 168         else if (r < glb_config.p_bubble_group[2])
 169                 n = 3;
 170         else
 171                 n = 4;
 172
 173         /* Initial position of top-most bubble in group. */
 174         x = glb_drand() * 4 - 2;
 175         y = glb_config.screen_bottom;
 176         z = glb_drand() * 2 - 2;
 177
 178         /* What size? */
 179         size = glb_config.min_size
 180                 + glb_drand() * (glb_config.max_size - glb_config.min_size);
 181
 182         /* What speed? */
 183         speed = glb_config.min_speed
 184                 + glb_drand() * (glb_config.max_speed - glb_config.min_speed);
 185
 186         /* Work out the scaling increment. Bubbles should increase by scale_factor
 187          * as they go from bottom to top of screen.
 188          */
 189         scale_incr = (size * glb_config.scale_factor - size)
 190                 / ((glb_config.screen_top - glb_config.screen_bottom) / speed);
 191
 192         /* Create the bubble(s). */
 193         for (i = 0; i < n; ++i) {
 194                 if ((b[i] = glb_bubble_new(x, y, z, size, speed, scale_incr)) == 0) {
 195                         /* Out of memory - recover. */
 196                         i--;
 197                         while (i >= 0)
 198                                 glb_bubble_delete(b[i]);
 199                         return 0;
 200                 }
 201                 /* Create the next bubble below the last bubble. */
 202                 y -= size * 3;
 203         }
 204
 205         /* Add the bubbles to the list. */
 206         c->nr_bubbles += n;
 207         old_bubble_list = c->bubble_list;
 208         if (c->bubble_list == 0) {
 209                 c->bubble_list = (void **) malloc(c->nr_bubbles * sizeof (void *));
 210         } else {
 211                 c->bubble_list = (void **) realloc(c->bubble_list,
 212                                             c->nr_bubbles * sizeof (void *));
 213         }
 214
 215         if (c->bubble_list == 0) {
 216                 /* Out of memory - recover. */
 217                 for (i = 0; i < n; ++i)
 218                         glb_bubble_delete(b[i]);
 219                 c->bubble_list = old_bubble_list;
 220                 c->nr_bubbles -= n;
 221                 return 0;
 222         }
 223         for (i = 0; i < n; ++i)
 224                 c->bubble_list[c->nr_bubbles - i - 1] = b[i];
 225
 226         return 1;
 227 }
 228
 229 void
 230 glb_draw_step(void *cc)
 231 {
 232         draw_context *c = (draw_context *) cc;
 233         int         i;
 234
 235         /* Consider creating a new bubble or bubbles. */
 236         if (c->nr_bubbles < glb_config.max_bubbles &&
 237             c->bubble_count++ > glb_config.create_bubbles_every) {
 238                 if (create_new_bubbles(c))
 239                         c->bubble_count = 0;
 240         }
 241         /* Clear the display. */
 242         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 243
 244         /* XXX Draw the background here ... */
 245
 246         /* Draw all the bubbles on the display. */
 247         for (i = 0; i < c->nr_bubbles; ++i) {
 248                 void       *b = c->bubble_list[i];
 249
 250                 glb_bubble_step(b);
 251                 glb_bubble_draw(b);
 252
 253                 /* Has the bubble reached the top of the screen? */
 254                 if (glb_bubble_get_y(b) >= glb_config.screen_top) {
 255                         delete_bubble(c, i);
 256                         i--;
 257                 }
 258         }
 259 }