Test glCopyTexSubImage2D by drawing gears as texture on sides of a box.

1 files changed, 486 insertions, 0 deletions

diff --git a/progs/demos/gearbox.c b/progs/demos/gearbox.c
new file mode 100644
index 0000000000..fa4cbe726f
--- /dev/null
+++ b/progs/demos/gearbox.c
@@ -0,0 +1,486 @@
+/*
+ * Use glCopyTexSubImage2D to draw animated gears on the sides of a box.
+ *
+ * Brian Paul
+ * 27 January 2006
+ */
+
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <GL/glut.h>
+
+#ifndef M_PI
+#define M_PI 3.14159265
+#endif
+
+static GLint WinWidth = 800, WinHeight = 500;
+static GLint TexWidth, TexHeight;
+static GLuint TexObj = 1;
+static GLenum IntFormat = GL_RGB;
+
+static GLboolean WireFrame = GL_FALSE;
+
+static GLint T0 = 0;
+static GLint Frames = 0;
+static GLint Win = 0;
+
+static GLfloat ViewRotX = 20.0, ViewRotY = 30.0, ViewRotZ = 0.0;
+static GLint Gear1, Gear2, Gear3;
+static GLfloat GearRot = 0.0;
+static GLfloat CubeRot = 0.0;
+
+
+/**
+  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 void
+gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
+     GLint teeth, GLfloat tooth_depth)
+{
+  GLint i;
+  GLfloat r0, r1, r2;
+  GLfloat angle, da;
+  GLfloat u, v, len;
+
+  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;
+
+  glShadeModel(GL_FLAT);
+
+  glNormal3f(0.0, 0.0, 1.0);
+
+  /* draw front face */
+  glBegin(GL_QUAD_STRIP);
+  for (i = 0; i <= teeth; i++) {
+    angle = i * 2.0 * M_PI / teeth;
+    glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
+    glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
+    if (i < teeth) {
+      glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
+      glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5);
+    }
+  }
+  glEnd();
+
+  /* draw front sides of teeth */
+  glBegin(GL_QUADS);
+  da = 2.0 * M_PI / teeth / 4.0;
+  for (i = 0; i < teeth; i++) {
+    angle = i * 2.0 * M_PI / teeth;
+
+    glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
+    glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
+    glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), width * 0.5);
+    glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5);
+  }
+  glEnd();
+
+  glNormal3f(0.0, 0.0, -1.0);
+
+  /* draw back face */
+  glBegin(GL_QUAD_STRIP);
+  for (i = 0; i <= teeth; i++) {
+    angle = i * 2.0 * M_PI / teeth;
+    glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
+    glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
+    if (i < teeth) {
+      glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5);
+      glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
+    }
+  }
+  glEnd();
+
+  /* draw back sides of teeth */
+  glBegin(GL_QUADS);
+  da = 2.0 * M_PI / teeth / 4.0;
+  for (i = 0; i < teeth; i++) {
+    angle = i * 2.0 * M_PI / teeth;
+
+    glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5);
+    glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), -width * 0.5);
+    glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
+    glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
+  }
+  glEnd();
+
+  /* draw outward faces of teeth */
+  glBegin(GL_QUAD_STRIP);
+  for (i = 0; i < teeth; i++) {
+    angle = i * 2.0 * M_PI / teeth;
+
+    glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
+    glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
+    u = r2 * cos(angle + da) - r1 * cos(angle);
+    v = r2 * sin(angle + da) - r1 * sin(angle);
+    len = sqrt(u * u + v * v);
+    u /= len;
+    v /= len;
+    glNormal3f(v, -u, 0.0);
+    glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
+    glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
+    glNormal3f(cos(angle), sin(angle), 0.0);
+    glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), width * 0.5);
+    glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), -width * 0.5);
+    u = r1 * cos(angle + 3 * da) - r2 * cos(angle + 2 * da);
+    v = r1 * sin(angle + 3 * da) - r2 * sin(angle + 2 * da);
+    glNormal3f(v, -u, 0.0);
+    glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5);
+    glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5);
+    glNormal3f(cos(angle), sin(angle), 0.0);
+  }
+
+  glVertex3f(r1 * cos(0), r1 * sin(0), width * 0.5);
+  glVertex3f(r1 * cos(0), r1 * sin(0), -width * 0.5);
+
+  glEnd();
+
+  glShadeModel(GL_SMOOTH);
+
+  /* draw inside radius cylinder */
+  glBegin(GL_QUAD_STRIP);
+  for (i = 0; i <= teeth; i++) {
+    angle = i * 2.0 * M_PI / teeth;
+    glNormal3f(-cos(angle), -sin(angle), 0.0);
+    glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
+    glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
+  }
+  glEnd();
+
+}
+
+static void
+cleanup(void)
+{
+   glDeleteTextures(1, &TexObj);
+   glDeleteLists(Gear1, 1);
+   glDeleteLists(Gear2, 1);
+   glDeleteLists(Gear3, 1);
+   glutDestroyWindow(Win);
+}
+
+
+static void
+DrawGears(void)
+{
+   if (WireFrame) {
+      glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+   }
+
+   glPushMatrix();
+      glRotatef(20/*ViewRotX*/, 1.0, 0.0, 0.0);
+      glRotatef(ViewRotY, 0.0, 1.0, 0.0);
+      glRotatef(ViewRotZ, 0.0, 0.0, 1.0);
+
+      glPushMatrix();
+         glTranslatef(-3.0, -2.0, 0.0);
+         glRotatef(GearRot, 0.0, 0.0, 1.0);
+         glCallList(Gear1);
+      glPopMatrix();
+
+      glPushMatrix();
+         glTranslatef(3.1, -2.0, 0.0);
+         glRotatef(-2.0 * GearRot - 9.0, 0.0, 0.0, 1.0);
+         glCallList(Gear2);
+      glPopMatrix();
+
+      glPushMatrix();
+         glTranslatef(-3.1, 4.2, 0.0);
+         glRotatef(-2.0 * GearRot - 25.0, 0.0, 0.0, 1.0);
+         glCallList(Gear3);
+      glPopMatrix();
+
+  glPopMatrix();
+
+  glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+}
+
+
+static void
+DrawCube(void)
+{
+   static const GLfloat texcoords[4][2] = {
+      { 0, 0 }, { 1, 0 }, { 1, 1 }, { 0, 1 }
+   };
+   static const GLfloat vertices[4][2] = {
+      { -1, -1 }, { 1, -1 }, { 1, 1 }, { -1, 1 }
+   };
+   static const GLfloat xforms[6][4] = {
+      {   0, 0, 1, 0 },
+      {  90, 0, 1, 0 },
+      { 180, 0, 1, 0 },
+      { 270, 0, 1, 0 },
+      {  90, 1, 0, 0 },
+      { -90, 1, 0, 0 }
+   };
+   static const GLfloat mat[4] = { 1.0, 1.0, 0.5, 1.0 };
+   GLint i, j;
+
+   glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, mat);
+   glEnable(GL_TEXTURE_2D);
+
+   glPushMatrix();
+      glRotatef(ViewRotX, 1.0, 0.0, 0.0);
+      glRotatef(15, 1, 0, 0);
+      glRotatef(CubeRot, 0, 1, 0);
+      glScalef(4, 4, 4);
+
+      for (i = 0; i < 6; i++) {
+         glPushMatrix();
+            glRotatef(xforms[i][0], xforms[i][1], xforms[i][2], xforms[i][3]);
+            glTranslatef(0, 0, 1.1);
+            glBegin(GL_POLYGON);
+               glNormal3f(0, 0, 1);
+               for (j = 0; j < 4; j++) {
+                  glTexCoord2fv(texcoords[j]);
+                  glVertex2fv(vertices[j]);
+               }
+            glEnd();
+         glPopMatrix();
+      }
+   glPopMatrix();
+
+   glDisable(GL_TEXTURE_2D);
+}
+
+
+static void
+draw(void)
+{
+   float ar;
+
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+   glTranslatef(0.0, 0.0, -40.0);
+
+   glDisable(GL_SCISSOR_TEST);
+   glClear(GL_DEPTH_BUFFER_BIT);
+   glEnable(GL_SCISSOR_TEST);
+
+   /* draw gears */
+   glViewport(0, 0, TexWidth, TexHeight);
+   glScissor(0, 0, TexWidth, TexHeight);
+   glClearColor(0.5, 0.5, 0.8, 0.0);
+   glClearColor(1, 1, 1, 0);
+   glClear(GL_COLOR_BUFFER_BIT);
+
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 60.0);
+   glMatrixMode(GL_MODELVIEW);
+
+   DrawGears();
+
+   glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, TexWidth, TexHeight);
+   
+   /* draw textured cube */
+   glViewport(TexWidth, 0, WinWidth - TexWidth, WinHeight);
+   glScissor(TexWidth, 0, WinWidth - TexWidth, WinHeight);
+   glClearColor(0.5, 0.5, 0.8, 0.0);
+   glClear(GL_COLOR_BUFFER_BIT);
+
+   ar = (float) (WinWidth - TexWidth) / WinHeight;
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glFrustum(-ar, ar, -1.0, 1.0, 5.0, 60.0);
+   glMatrixMode(GL_MODELVIEW);
+
+   DrawCube();
+
+   /* finish up */
+   glutSwapBuffers();
+
+   Frames++;
+   {
+      GLint t = glutGet(GLUT_ELAPSED_TIME);
+      if (t - T0 >= 5000) {
+         GLfloat seconds = (t - T0) / 1000.0;
+         GLfloat fps = Frames / seconds;
+         printf("%d frames in %6.3f seconds = %6.3f FPS\n", Frames, seconds, fps);
+         T0 = t;
+         Frames = 0;
+      }
+   }
+}
+
+
+static void
+idle(void)
+{
+  static double t0 = -1.;
+  double dt, t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;
+  if (t0 < 0.0)
+    t0 = t;
+  dt = t - t0;
+  t0 = t;
+
+  GearRot += 70.0 * dt;  /* 70 degrees per second */
+  GearRot = fmod(GearRot, 360.0); /* prevents eventual overflow */
+
+  CubeRot += 15.0 * dt;
+
+  glutPostRedisplay();
+}
+
+
+/* change view angle, exit upon ESC */
+static void
+key(unsigned char k, int x, int y)
+{
+   (void) x;
+   (void) y;
+   switch (k) {
+   case 'w':
+      WireFrame = !WireFrame;
+      break;
+   case 'z':
+      ViewRotZ += 5.0;
+      break;
+   case 'Z':
+      ViewRotZ -= 5.0;
+      break;
+   case 27:  /* Escape */
+      cleanup();
+      exit(0);
+      break;
+   default:
+      return;
+   }
+   glutPostRedisplay();
+}
+
+/* change view angle */
+static void
+special(int k, int x, int y)
+{
+   (void) x;
+   (void) y;
+   switch (k) {
+   case GLUT_KEY_UP:
+      ViewRotX += 5.0;
+      break;
+   case GLUT_KEY_DOWN:
+      ViewRotX -= 5.0;
+      break;
+   case GLUT_KEY_LEFT:
+      ViewRotY += 5.0;
+      break;
+   case GLUT_KEY_RIGHT:
+      ViewRotY -= 5.0;
+      break;
+   default:
+      return;
+   }
+   glutPostRedisplay();
+}
+
+
+/* new window size or exposure */
+static void
+reshape(int width, int height)
+{
+  WinWidth = width;
+  WinHeight = height;
+}
+
+
+static void
+init(int argc, char *argv[])
+{
+  static GLfloat pos[4] = {5.0, 5.0, 10.0, 0.0};
+  static GLfloat red[4] = {0.8, 0.1, 0.0, 1.0};
+  static GLfloat green[4] = {0.0, 0.8, 0.2, 1.0};
+  static GLfloat blue[4] = {0.2, 0.2, 1.0, 1.0};
+  GLint i;
+
+  glLightfv(GL_LIGHT0, GL_POSITION, pos);
+#if 0
+  glEnable(GL_CULL_FACE);
+#endif
+  glEnable(GL_LIGHTING);
+  glEnable(GL_LIGHT0);
+  glEnable(GL_DEPTH_TEST);
+
+  /* make the gears */
+  Gear1 = glGenLists(1);
+  glNewList(Gear1, GL_COMPILE);
+  glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red);
+  gear(1.0, 4.0, 1.0, 20, 0.7);
+  glEndList();
+
+  Gear2 = glGenLists(1);
+  glNewList(Gear2, GL_COMPILE);
+  glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green);
+  gear(0.5, 2.0, 2.0, 10, 0.7);
+  glEndList();
+
+  Gear3 = glGenLists(1);
+  glNewList(Gear3, GL_COMPILE);
+  glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue);
+  gear(1.3, 2.0, 0.5, 10, 0.7);
+  glEndList();
+
+  glEnable(GL_NORMALIZE);
+
+  /* xxx make size dynamic */
+  TexWidth = 256;
+  TexHeight = 256;
+
+   glBindTexture(GL_TEXTURE_2D, TexObj);
+   glTexImage2D(GL_TEXTURE_2D, 0, IntFormat, TexWidth, TexHeight, 0,
+                GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+   glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+
+  for ( i=1; i<argc; i++ ) {
+    if (strcmp(argv[i], "-info")==0) {
+      printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
+      printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
+      printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
+      printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
+    }
+  }
+}
+
+
+static void 
+visible(int vis)
+{
+  if (vis == GLUT_VISIBLE)
+    glutIdleFunc(idle);
+  else
+    glutIdleFunc(NULL);
+}
+
+
+int
+main(int argc, char *argv[])
+{
+   glutInit(&argc, argv);
+   glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
+
+   glutInitWindowSize(WinWidth, WinHeight);
+   Win = glutCreateWindow("gearbox");
+   init(argc, argv);
+
+   glutDisplayFunc(draw);
+   glutReshapeFunc(reshape);
+   glutKeyboardFunc(key);
+   glutSpecialFunc(special);
+   glutVisibilityFunc(visible);
+
+   glutMainLoop();
+   return 0;             /* ANSI C requires main to return int. */
+}