/* * Spinning gears demo for Linux SVGA/Mesa interface in 32K color mode. * * Compile with: gcc vgears.c -I../include -L../lib -lMesaGL -lX11 -lXext * -lvga -lm -o vgears * * This program is in the public domain. * Brian Paul, January 1996 */ #include <vga.h> #include <math.h> #include "GL/svgamesa.h" #include "GL/gl.h" int width = 800, height = 600; SVGAMesaContext vmc; /* * 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 ); 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 ); 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 GLfloat view_rotx=20.0, view_roty=30.0, view_rotz=0.0; static GLint gear1, gear2, gear3; static GLfloat angle = 0.0; static GLuint limit; static GLuint count = 1; static void draw( void ) { angle += 2.0; glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); glPushMatrix(); glRotatef( view_rotx, 1.0, 0.0, 0.0 ); glRotatef( view_roty, 0.0, 1.0, 0.0 ); glRotatef( view_rotz, 0.0, 0.0, 1.0 ); glPushMatrix(); glTranslatef( -3.0, -2.0, 0.0 ); glRotatef( angle, 0.0, 0.0, 1.0 ); glCallList(gear1); glPopMatrix(); glPushMatrix(); glTranslatef( 3.1, -2.0, 0.0 ); glRotatef( -2.0*angle-9.0, 0.0, 0.0, 1.0 ); glCallList(gear2); glPopMatrix(); glPushMatrix(); glTranslatef( -3.1, 4.2, 0.0 ); glRotatef( -2.0*angle-25.0, 0.0, 0.0, 1.0 ); glCallList(gear3); glPopMatrix(); glPopMatrix(); SVGAMesaSwapBuffers(); } static void init( void ) { static GLfloat pos[4] = {5.0, 5.0, 10.0, 1.0 }; 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 }; GLfloat w = (float) width / (float) height; GLfloat h = 1.0; glLightfv( GL_LIGHT0, GL_POSITION, pos ); glEnable( GL_CULL_FACE ); 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 ); glViewport( 0, 0, width, height ); glMatrixMode(GL_PROJECTION); glLoadIdentity(); if (width>height) { GLfloat w = (GLfloat) width / (GLfloat) height; glFrustum( -w, w, -1.0, 1.0, 5.0, 60.0 ); } else { GLfloat h = (GLfloat) height / (GLfloat) width; glFrustum( -1.0, 1.0, -h, h, 5.0, 60.0 ); } glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glTranslatef( 0.0, 0.0, -40.0 ); } void setup( void ) { vga_init(); vga_setmode(G800x600x32K); /* gl_setcontextvga(G800x600x32K);*/ vmc = SVGAMesaCreateContext(GL_TRUE); SVGAMesaMakeCurrent( vmc ); } void end( void ) { SVGAMesaDestroyContext( vmc ); vga_setmode( TEXT ); } int main( int argc, char *argv[] ) { int i; setup(); init(); for (i=0;i<4;i++) { draw(); /*SVGAMesaSwapBuffers();*/ } end(); return 0; }