* Since I'm not a native English speaker, my apologies for any grammatical
* mistake.
*
- * My e-mail addresses are
- * vianna@cat.cbpf.br
- * and
+ * My e-mail address is
* m-vianna@usa.net
*
* Marcelo F. Vianna (Jun-01-1997)
* mapping shuld work on PseudoColor, DirectColor, TrueColor using Mesa. Mono
* is not officially supported for both OpenGL and Mesa, but seems to not crash
* Mesa.
-z *
+ *
* In real OpenGL, PseudoColor DO NOT support texture map (as far as I know).
*/
# define PROGCLASS "Stairs"
# define HACK_INIT init_stairs
# define HACK_DRAW draw_stairs
+# define HACK_RESHAPE reshape_stairs
# define stairs_opts xlockmore_opts
-# define DEFAULTS "*cycles: 1 \n" \
- "*delay: 200000 \n" \
+# define DEFAULTS "*delay: 20000 \n" \
+ "*showFPS: False \n" \
"*wireframe: False \n"
# include "xlockmore.h" /* from the xscreensaver distribution */
#else /* !STANDALONE */
ModStruct stairs_description =
{"stairs", "init_stairs", "draw_stairs", "release_stairs",
"draw_stairs", "change_stairs", NULL, &stairs_opts,
- 1000, 1, 1, 1, 1.0, "",
+ 1000, 1, 1, 1, 4, 1.0, "",
"Shows Infinite Stairs, an Escher-like scene", 0, NULL};
#endif
GLint WindH, WindW;
GLfloat step;
Bool direction;
- int AreObjectsDefined[1];
- int sphere_position;
+ int AreObjectsDefined[1];
+ int sphere_position;
+ int sphere_tick;
GLXContext *glx_context;
} stairsstruct;
{0.6, 0.6, 0.6, 1.0};
static float MaterialGray8[] =
{0.8, 0.8, 0.8, 1.0};
+
#endif
static float MaterialYellow[] =
{0.7, 0.7, 0.0, 1.0};
static float positions[] =
{
- -2.5, 4.0, 0.0, /* First one is FUDGED :) */
- -3.0, 3.25, 1.0,
- -3.0, 4.4, 1.5,
- -3.0, 3.05, 2.0,
- -3.0, 4.2, 2.5,
-
- -3.0, 2.85, 3.0,
- -2.5, 4.0, 3.0,
- -2.0, 2.75, 3.0,
- -1.5, 3.9, 3.0,
- -1.0, 2.65, 3.0,
- -0.5, 3.8, 3.0,
- 0.0, 2.55, 3.0,
- 0.5, 3.7, 3.0,
- 1.0, 2.45, 3.0,
- 1.5, 3.6, 3.0,
- 2.0, 2.35, 3.0,
-
- 2.0, 3.5, 2.5,
- 2.0, 2.25, 2.0,
- 2.0, 3.4, 1.5,
- 2.0, 2.15, 1.0,
- 2.0, 3.3, 0.5,
- 2.0, 2.05, 0.0,
- 2.0, 3.2, -0.5,
- 2.0, 1.95, -1.0,
- 2.0, 3.1, -1.5,
- 2.0, 1.85, -2.0,
-
- 1.5, 2.9, -2.0,
- 1.0, 1.65, -2.0,
- 0.5, 2.7, -2.0,
- 0.0, 1.55, -2.0,
- -0.5, 2.5, -2.0,
- -1.0, 1.45, -2.0,
+ -2.5, 4.0, 0.0, /* First one is FUDGED :) */
+ -3.0, 3.25, 1.0,
+ -3.0, 4.4, 1.5,
+ -3.0, 3.05, 2.0,
+ -3.0, 4.2, 2.5,
+
+ -3.0, 2.85, 3.0,
+ -2.5, 4.0, 3.0,
+ -2.0, 2.75, 3.0,
+ -1.5, 3.9, 3.0,
+ -1.0, 2.65, 3.0,
+ -0.5, 3.8, 3.0,
+ 0.0, 2.55, 3.0,
+ 0.5, 3.7, 3.0,
+ 1.0, 2.45, 3.0,
+ 1.5, 3.6, 3.0,
+ 2.0, 2.35, 3.0,
+
+ 2.0, 3.5, 2.5,
+ 2.0, 2.25, 2.0,
+ 2.0, 3.4, 1.5,
+ 2.0, 2.15, 1.0,
+ 2.0, 3.3, 0.5,
+ 2.0, 2.05, 0.0,
+ 2.0, 3.2, -0.5,
+ 2.0, 1.95, -1.0,
+ 2.0, 3.1, -1.5,
+ 2.0, 1.85, -2.0,
+
+ 1.5, 2.9, -2.0,
+ 1.0, 1.65, -2.0,
+ 0.5, 2.7, -2.0,
+ 0.0, 1.55, -2.0,
+ -0.5, 2.5, -2.0,
+ -1.0, 1.45, -2.0,
};
+
#define NPOSITIONS ((sizeof positions) / (sizeof positions[0]))
+#define SPHERE_TICKS 8
+
static stairsstruct *stairs = NULL;
static GLuint objects;
}
static void
-draw_block(stairsstruct * sp, GLfloat width, GLfloat height, GLfloat thickness)
-{
- glBegin(GL_QUADS);
- glNormal3f(0, 0, 1);
- glTexCoord2f(0, 0);
- glVertex3f(-width, -height, thickness);
- glTexCoord2f(1, 0);
- glVertex3f(width, -height, thickness);
- glTexCoord2f(1, 1);
- glVertex3f(width, height, thickness);
- glTexCoord2f(0, 1);
- glVertex3f(-width, height, thickness);
- glNormal3f(0, 0, -1);
- glTexCoord2f(0, 0);
- glVertex3f(-width, height, -thickness);
- glTexCoord2f(1, 0);
- glVertex3f(width, height, -thickness);
- glTexCoord2f(1, 1);
- glVertex3f(width, -height, -thickness);
- glTexCoord2f(0, 1);
- glVertex3f(-width, -height, -thickness);
- glNormal3f(0, 1, 0);
- glTexCoord2f(0, 0);
- glVertex3f(-width, height, thickness);
- glTexCoord2f(1, 0);
- glVertex3f(width, height, thickness);
- glTexCoord2f(1, 1);
- glVertex3f(width, height, -thickness);
- glTexCoord2f(0, 1);
- glVertex3f(-width, height, -thickness);
- glNormal3f(0, -1, 0);
- glTexCoord2f(0, 0);
- glVertex3f(-width, -height, -thickness);
- glTexCoord2f(1, 0);
- glVertex3f(width, -height, -thickness);
- glTexCoord2f(1, 1);
- glVertex3f(width, -height, thickness);
- glTexCoord2f(0, 1);
- glVertex3f(-width, -height, thickness);
- glNormal3f(1, 0, 0);
- glTexCoord2f(0, 0);
- glVertex3f(width, -height, thickness);
- glTexCoord2f(1, 0);
- glVertex3f(width, -height, -thickness);
- glTexCoord2f(1, 1);
- glVertex3f(width, height, -thickness);
- glTexCoord2f(0, 1);
- glVertex3f(width, height, thickness);
- glNormal3f(-1, 0, 0);
- glTexCoord2f(0, 0);
- glVertex3f(-width, height, thickness);
- glTexCoord2f(1, 0);
- glVertex3f(-width, height, -thickness);
- glTexCoord2f(1, 1);
- glVertex3f(-width, -height, -thickness);
- glTexCoord2f(0, 1);
- glVertex3f(-width, -height, thickness);
- glEnd();
-}
-
-static void
-draw_degree(stairsstruct * sp, GLfloat w, GLfloat h , GLfloat t)
+draw_block(GLfloat width, GLfloat height, GLfloat thickness)
{
- draw_block(sp, w, h, t);
+ glBegin(GL_QUADS);
+ glNormal3f(0, 0, 1);
+ glTexCoord2f(0, 0);
+ glVertex3f(-width, -height, thickness);
+ glTexCoord2f(1, 0);
+ glVertex3f(width, -height, thickness);
+ glTexCoord2f(1, 1);
+ glVertex3f(width, height, thickness);
+ glTexCoord2f(0, 1);
+ glVertex3f(-width, height, thickness);
+ glNormal3f(0, 0, -1);
+ glTexCoord2f(0, 0);
+ glVertex3f(-width, height, -thickness);
+ glTexCoord2f(1, 0);
+ glVertex3f(width, height, -thickness);
+ glTexCoord2f(1, 1);
+ glVertex3f(width, -height, -thickness);
+ glTexCoord2f(0, 1);
+ glVertex3f(-width, -height, -thickness);
+ glNormal3f(0, 1, 0);
+ glTexCoord2f(0, 0);
+ glVertex3f(-width, height, thickness);
+ glTexCoord2f(1, 0);
+ glVertex3f(width, height, thickness);
+ glTexCoord2f(1, 1);
+ glVertex3f(width, height, -thickness);
+ glTexCoord2f(0, 1);
+ glVertex3f(-width, height, -thickness);
+ glNormal3f(0, -1, 0);
+ glTexCoord2f(0, 0);
+ glVertex3f(-width, -height, -thickness);
+ glTexCoord2f(1, 0);
+ glVertex3f(width, -height, -thickness);
+ glTexCoord2f(1, 1);
+ glVertex3f(width, -height, thickness);
+ glTexCoord2f(0, 1);
+ glVertex3f(-width, -height, thickness);
+ glNormal3f(1, 0, 0);
+ glTexCoord2f(0, 0);
+ glVertex3f(width, -height, thickness);
+ glTexCoord2f(1, 0);
+ glVertex3f(width, -height, -thickness);
+ glTexCoord2f(1, 1);
+ glVertex3f(width, height, -thickness);
+ glTexCoord2f(0, 1);
+ glVertex3f(width, height, thickness);
+ glNormal3f(-1, 0, 0);
+ glTexCoord2f(0, 0);
+ glVertex3f(-width, height, thickness);
+ glTexCoord2f(1, 0);
+ glVertex3f(-width, height, -thickness);
+ glTexCoord2f(1, 1);
+ glVertex3f(-width, -height, -thickness);
+ glTexCoord2f(0, 1);
+ glVertex3f(-width, -height, thickness);
+ glEnd();
}
static void
-draw_stairs_internal(ModeInfo *mi)
+draw_stairs_internal(ModeInfo * mi)
{
stairsstruct *sp = &stairs[MI_SCREEN(mi)];
- GLfloat X;
-
- glPushMatrix();
- glPushMatrix();
- glTranslatef(-3.0, 0.1, 2.0);
- for (X=0; X< 2; X++) {
- draw_degree(sp, 0.5, 2.7+0.1*X, 0.5);
- glTranslatef( 0.0, 0.1,-1.0);
- }
+ GLfloat X;
+
+ glPushMatrix();
+ glPushMatrix();
+ glTranslatef(-3.0, 0.1, 2.0);
+ for (X = 0; X < 2; X++) {
+ draw_block(0.5, 2.7 + 0.1 * X, 0.5);
+ glTranslatef(0.0, 0.1, -1.0);
+ }
glPopMatrix();
- glTranslatef(-3.0, 0.0, 3.0);
- glPushMatrix();
-
- for (X=0; X< 6; X++) {
- draw_degree(sp, 0.5, 2.6-0.1*X, 0.5);
- glTranslatef( 1.0,-0.1, 0.0);
- }
- glTranslatef(-1.0,-0.9,-1.0);
- for (X=0; X< 5; X++) {
- draw_degree(sp, 0.5, 3.0-0.1*X, 0.5);
- glTranslatef( 0.0, 0.0,-1.0);
- }
- glTranslatef(-1.0,-1.1, 1.0);
- for (X=0; X< 3; X++) {
- draw_degree(sp, 0.5, 3.5-0.1*X, 0.5);
- glTranslatef(-1.0,-0.1, 0.0);
- }
+ glTranslatef(-3.0, 0.0, 3.0);
+ glPushMatrix();
+
+ for (X = 0; X < 6; X++) {
+ draw_block(0.5, 2.6 - 0.1 * X, 0.5);
+ glTranslatef(1.0, -0.1, 0.0);
+ }
+ glTranslatef(-1.0, -0.9, -1.0);
+ for (X = 0; X < 5; X++) {
+ draw_block(0.5, 3.0 - 0.1 * X, 0.5);
+ glTranslatef(0.0, 0.0, -1.0);
+ }
+ glTranslatef(-1.0, -1.1, 1.0);
+ for (X = 0; X < 3; X++) {
+ draw_block(0.5, 3.5 - 0.1 * X, 0.5);
+ glTranslatef(-1.0, -0.1, 0.0);
+ }
glPopMatrix();
glPopMatrix();
- glPushMatrix();
- glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialYellow);
-
- glTranslatef((GLfloat) positions[sp->sphere_position],
- (GLfloat) positions[sp->sphere_position + 1],
- (GLfloat) positions[sp->sphere_position + 2]);
- if (sp->sphere_position == 0) /* FUDGE soo its not so obvious */
- mySphere(0.48);
- else
- mySphere(0.5);
- glPopMatrix();
- sp->sphere_position += 3;
- if (sp->sphere_position >= NPOSITIONS)
- sp->sphere_position = 0;
+ glPushMatrix();
+ glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialYellow);
+
+ {
+ int pos = sp->sphere_position;
+ int ppos = sp->sphere_position - 3;
+ int npos = sp->sphere_position + 3;
+ GLfloat spx, spy, spz;
+ GLfloat dx, dy, dz;
+ int div;
+
+ if (ppos < 0) ppos += NPOSITIONS;
+ if (npos >= NPOSITIONS) npos -= NPOSITIONS;
+
+ if (sp->sphere_tick < 0)
+ {
+ dx = positions[ppos] - positions[pos];
+ dy = positions[ppos+1] - positions[pos+1];
+ dz = positions[ppos+2] - positions[pos+2];
+ div = SPHERE_TICKS + sp->sphere_tick;
+ }
+ else
+ {
+ dx = positions[npos] - positions[pos];
+ dy = positions[npos+1] - positions[pos+1];
+ dz = positions[npos+2] - positions[ppos+2];
+ div = SPHERE_TICKS - sp->sphere_tick;
+ }
+
+ spx = positions[pos];
+ spy = positions[pos+1];
+ spz = positions[pos+2];
+ if (div != 0)
+ {
+ spx += dx / div;
+ spy += dy / div;
+ spz += dz / div;
+ }
+
+
+ spy -= 0.5; /* move the bottom of the ball closer to the stairs */
+
+
+#ifdef DEBUG
+ fprintf(stderr, "%3d %3d %2.2f %2.2f %2.2f %2.2f %2.2f %2.2f\n",
+ sp->sphere_position, sp->sphere_tick,
+ dx, dy, dz,
+ spx, spy, spz);
+
+ glBegin(GL_LINE_LOOP); /* path 1 */
+ glVertex3f(positions[pos], positions[pos+1], positions[pos+2]);
+ glVertex3f(positions[npos], positions[npos+1], positions[npos+2]);
+ glEnd();
+
+ glBegin(GL_LINE_LOOP); /* path 2 */
+ glVertex3f(positions[pos], positions[pos+1], positions[pos+2]);
+ glVertex3f(positions[ppos], positions[ppos+1], positions[ppos+2]);
+ glEnd();
+
+ glBegin(GL_LINE_LOOP); /* base origin */
+ glVertex3f(positions[pos], positions[pos+1]-10, positions[pos+2]);
+ glVertex3f(positions[pos], positions[pos+1]+10, positions[pos+2]);
+ glEnd();
+
+ glBegin(GL_LINE_LOOP); /* base origin */
+ glVertex3f(positions[pos]-10, positions[pos+1], positions[pos+2]);
+ glVertex3f(positions[pos]+10, positions[pos+1], positions[pos+2]);
+ glEnd();
+
+ glBegin(GL_LINE_LOOP); /* base origin */
+ glVertex3f(positions[pos], positions[pos+1], positions[pos+2]-10);
+ glVertex3f(positions[pos], positions[pos+1], positions[pos+2]+10);
+ glEnd();
+#endif /* DEBUG */
+
+ glTranslatef(spx, spy, spz);
+
+#ifdef DEBUG /* ball origin */
+ glBegin(GL_LINE_LOOP); glVertex3f(0,-2,0); glVertex3f(0,2,0); glEnd();
+ glBegin(GL_LINE_LOOP); glVertex3f(-2,0,0); glVertex3f(2,0,0); glEnd();
+ glBegin(GL_LINE_LOOP); glVertex3f(0,0,-2); glVertex3f(0,0,2); glEnd();
+#endif /* DEBUG */
+ }
+
+ if (sp->sphere_position == 0) /* FUDGE soo its not so obvious */
+ mySphere(0.48);
+ else
+ mySphere(0.5);
+ glPopMatrix();
+
+ if (++sp->sphere_tick >= SPHERE_TICKS-1)
+ {
+ sp->sphere_tick = -(SPHERE_TICKS-2);
+ sp->sphere_position += 3;
+ sp->sphere_position += 3;
+ }
+
+ if (sp->sphere_position >= NPOSITIONS)
+ sp->sphere_position = 0;
}
-static void
-reshape(ModeInfo * mi, int width, int height)
+void
+reshape_stairs(ModeInfo * mi, int width, int height)
{
stairsstruct *sp = &stairs[MI_SCREEN(mi)];
}
static void
-pinit(ModeInfo * mi)
+pinit(void)
{
-/* stairsstruct *sp = &stairs[MI_SCREEN(mi)];*/
-
+ int status;
glClearDepth(1.0);
glClearColor(0.0, 0.0, 0.0, 1.0);
glFrontFace(GL_CCW);
glCullFace(GL_BACK);
- glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialWhite);
+ glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialWhite);
glShadeModel(GL_FLAT);
glEnable(GL_DEPTH_TEST);
glEnable(GL_TEXTURE_2D);
glEnable(GL_CULL_FACE);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
- gluBuild2DMipmaps(GL_TEXTURE_2D, 3, WoodTextureWidth, WoodTextureHeight,
- GL_RGB, GL_UNSIGNED_BYTE, WoodTextureData);
+
+ clear_gl_error();
+ status = gluBuild2DMipmaps(GL_TEXTURE_2D, 3,
+ WoodTextureWidth, WoodTextureHeight,
+ GL_RGB, GL_UNSIGNED_BYTE, WoodTextureData);
+ if (status)
+ {
+ const char *s = (char *) gluErrorString (status);
+ fprintf (stderr, "%s: error mipmapping %dx%d texture: %s\n",
+ progname, WoodTextureWidth, WoodTextureHeight,
+ (s ? s : "(unknown)"));
+ exit (1);
+ }
+ check_gl_error("mipmapping");
+
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
}
sp = &stairs[screen];
sp->step = 0.0;
- sp->direction = LRAND() & 1;
+ sp->direction = LRAND() & 1;
sp->sphere_position = NRAND(NPOSITIONS / 3) * 3;
+ sp->sphere_tick = 0;
if ((sp->glx_context = init_GL(mi)) != NULL) {
- reshape(mi, MI_WIN_WIDTH(mi), MI_WIN_HEIGHT(mi));
+ reshape_stairs(mi, MI_WIDTH(mi), MI_HEIGHT(mi));
glDrawBuffer(GL_BACK);
if (!glIsList(objects))
objects = glGenLists(1);
- pinit(mi);
+ pinit();
} else {
- MI_CLEARWINDOW(mi);
+ MI_CLEARWINDOW(mi);
}
}
glTranslatef(0.0, 0.0, -10.0);
- if (!MI_WIN_IS_ICONIC(mi)) {
+ if (!MI_IS_ICONIC(mi)) {
glScalef(Scale4Window * sp->WindH / sp->WindW, Scale4Window, Scale4Window);
} else {
glScalef(Scale4Iconic * sp->WindH / sp->WindW, Scale4Iconic, Scale4Iconic);
}
glRotatef(44.5, 1, 0, 0);
- glRotatef(50 + ((sp->direction) ? 1 : -1 ) *
- ((sp->step * 100 > 120) ? sp->step * 100 - 120 : 0), 0, 1, 0);
- if (sp->step * 100 >= 360 + 120) { /* stop showing secrets */
- sp->step = 0;
- sp->direction = LRAND() & 1;
- }
- draw_stairs_internal(mi);
+ glRotatef(50 + ((sp->direction) ? 1 : -1) *
+ ((sp->step * 100 > 120) ? sp->step * 100 - 120 : 0), 0, 1, 0);
+ if (sp->step * 100 >= 360 + 120) { /* stop showing secrets */
+ sp->step = 0;
+ sp->direction = LRAND() & 1;
+ }
+ draw_stairs_internal(mi);
glPopMatrix();
+ if (mi->fps_p) do_fps (mi);
glFlush();
glXSwapBuffers(display, window);
return;
glXMakeCurrent(MI_DISPLAY(mi), MI_WINDOW(mi), *(sp->glx_context));
- pinit(mi);
+ pinit();
}
void