--- /dev/null
+/*
+ * 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. */
+}
projects / mesa.git / commitdiff