began for maemo

[xscreensaver] / xscreensaver / hacks / glx / tube.c

diff --git a/xscreensaver/hacks/glx/tube.c b/xscreensaver/hacks/glx/tube.c
new file mode 100644 (file)
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+++ b/xscreensaver/hacks/glx/tube.c
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+/* tube, Copyright (c) 2001, 2003, 2007 Jamie Zawinski <jwz@jwz.org>
+ * Utility functions to create tubes and cones in GL.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation.  No representations are made about the suitability of this
+ * software for any purpose.  It is provided "as is" without express or 
+ * implied warranty.
+ */
+
+#include <math.h>
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <stdlib.h>
+
+#ifdef HAVE_COCOA
+# include <OpenGL/gl.h>
+#else
+# include <GL/gl.h>
+#endif
+
+#include "tube.h"
+
+static int
+unit_tube (int faces, int smooth, int caps_p, int wire_p)
+{
+  int i;
+  int polys = 0;
+  GLfloat step = M_PI * 2 / faces;
+  GLfloat s2 = step/2;
+  GLfloat th;
+  GLfloat x, y, x0=0, y0=0;
+  int z = 0;
+
+  /* side walls
+   */
+  glFrontFace(GL_CCW);
+  glBegin (wire_p ? GL_LINES : (smooth ? GL_QUAD_STRIP : GL_QUADS));
+
+  th = 0;
+  x = 1;
+  y = 0;
+
+  if (!smooth)
+    {
+      x0 = cos (s2);
+      y0 = sin (s2);
+    }
+
+  if (smooth) faces++;
+
+  for (i = 0; i < faces; i++)
+    {
+      if (smooth)
+        glNormal3f(x, 0, y);
+      else
+        glNormal3f(x0, 0, y0);
+
+      glVertex3f(x, 0, y);
+      glVertex3f(x, 1, y);
+
+      th += step;
+      x  = cos (th);
+      y  = sin (th);
+
+      if (!smooth)
+        {
+          x0 = cos (th + s2);
+          y0 = sin (th + s2);
+
+          glVertex3f(x, 1, y);
+          glVertex3f(x, 0, y);
+        }
+      polys++;
+    }
+  glEnd();
+
+  /* End caps
+   */
+  if (caps_p)
+    for (z = 0; z <= 1; z++)
+      {
+        glFrontFace(z == 0 ? GL_CCW : GL_CW);
+        glNormal3f(0, (z == 0 ? -1 : 1), 0);
+        glBegin(wire_p ? GL_LINE_LOOP : GL_TRIANGLE_FAN);
+        if (! wire_p) glVertex3f(0, z, 0);
+        for (i = 0, th = 0; i <= faces; i++)
+          {
+            GLfloat x = cos (th);
+            GLfloat y = sin (th);
+            glVertex3f(x, z, y);
+            th += step;
+            polys++;
+          }
+        glEnd();
+      }
+  return polys;
+}
+
+
+static int
+unit_cone (int faces, int smooth, int cap_p, int wire_p)
+{
+  int i;
+  int polys = 0;
+  GLfloat step = M_PI * 2 / faces;
+  GLfloat s2 = step/2;
+  GLfloat th;
+  GLfloat x, y, x0, y0;
+
+  /* side walls
+   */
+  glFrontFace(GL_CW);
+  glBegin(wire_p ? GL_LINES : GL_TRIANGLES);
+
+  th = 0;
+  x = 1;
+  y = 0;
+  x0 = cos (s2);
+  y0 = sin (s2);
+
+  for (i = 0; i < faces; i++)
+    {
+      glNormal3f(x0, 0, y0);
+      glVertex3f(0,  1, 0);
+
+      if (smooth) glNormal3f(x, 0, y);
+      glVertex3f(x, 0, y);
+
+      th += step;
+      x0 = cos (th + s2);
+      y0 = sin (th + s2);
+      x  = cos (th);
+      y  = sin (th);
+
+      if (smooth) glNormal3f(x, 0, y);
+      glVertex3f(x, 0, y);
+      polys++;
+    }
+  glEnd();
+
+  /* End cap
+   */
+  if (cap_p)
+    {
+      glFrontFace(GL_CCW);
+      glNormal3f(0, -1, 0);
+      glBegin(wire_p ? GL_LINE_LOOP : GL_TRIANGLE_FAN);
+      if (! wire_p) glVertex3f(0, 0, 0);
+      for (i = 0, th = 0; i <= faces; i++)
+        {
+          GLfloat x = cos (th);
+          GLfloat y = sin (th);
+          glVertex3f(x, 0, y);
+          th += step;
+          polys++;
+        }
+      glEnd();
+    }
+  return polys;
+}
+
+
+static int
+tube_1 (GLfloat x1, GLfloat y1, GLfloat z1,
+        GLfloat x2, GLfloat y2, GLfloat z2,
+        GLfloat diameter, GLfloat cap_size,
+        int faces, int smooth, int caps_p, int wire_p,
+        int cone_p)
+{
+  GLfloat length, X, Y, Z;
+  int polys = 0;
+
+  if (diameter <= 0) abort();
+
+  X = (x2 - x1);
+  Y = (y2 - y1);
+  Z = (z2 - z1);
+
+  if (X == 0 && Y == 0 && Z == 0)
+    return 0;
+
+  length = sqrt (X*X + Y*Y + Z*Z);
+
+  glPushMatrix();
+
+  glTranslatef(x1, y1, z1);
+  glRotatef (-atan2 (X, Y)               * (180 / M_PI), 0, 0, 1);
+  glRotatef ( atan2 (Z, sqrt(X*X + Y*Y)) * (180 / M_PI), 1, 0, 0);
+  glScalef (diameter, length, diameter);
+
+  /* extend the endpoints of the tube by the cap size in both directions */
+  if (cap_size != 0)
+    {
+      GLfloat c = cap_size/length;
+      glTranslatef (0, -c, 0);
+      glScalef (1, 1+c+c, 1);
+    }
+
+  if (cone_p)
+    polys = unit_cone (faces, smooth, caps_p, wire_p);
+  else
+    polys = unit_tube (faces, smooth, caps_p, wire_p);
+
+  glPopMatrix();
+  return polys;
+}
+
+
+int
+tube (GLfloat x1, GLfloat y1, GLfloat z1,
+      GLfloat x2, GLfloat y2, GLfloat z2,
+      GLfloat diameter, GLfloat cap_size,
+      int faces, int smooth, int caps_p, int wire_p)
+{
+  return tube_1 (x1, y1, z1, x2, y2, z2, diameter, cap_size,
+                 faces, smooth, caps_p, wire_p,
+                 0);
+}
+
+
+int
+cone (GLfloat x1, GLfloat y1, GLfloat z1,
+      GLfloat x2, GLfloat y2, GLfloat z2,
+      GLfloat diameter, GLfloat cap_size,
+      int faces, int smooth, int cap_p, int wire_p)
+{
+  return tube_1 (x1, y1, z1, x2, y2, z2, diameter, cap_size,
+                 faces, smooth, cap_p, wire_p,
+                 1);
+}