// ss5a.c // gcc -o ss5a ss5a.c -lgd -lpng -lm // // The perspective sucks // The light pressure of tilted thrusters is treated here as constant. // The actual light pressure is proportional to cos^2( sun angle ) // This assumes a 4:3 ratio, with gauges down the right side #define RMMKDIR "rm -rf ss5adir ; mkdir ss5adir" #define PNG2SWF "png2swf -o ss5a.swf -r 10 ss5adir/*.png" // tried to antialias with imagemagick - broke swftools, sigh //#define PNGFMT "ss5atmp.png" //#define CONVERT "convert ss5atmp.png -resize 800x600 ss5adir/a%04d.png" //#define FSZ 40 // this scales the font and the whole drawing #define PNGFMT "ss5adir/a%04d.png" #define CONVERT "" #define FSZ 20 // this scales the font and the whole drawing #define FNT "DejaVuMonoSans" #define SCALE 0.09 // size of serversat #define Z0 24.0 // depth scaling for cheesy perspective #define ACC 14 // acceleration in degrees/minute^2 #define TSTART 0 #define TIME1 120 // acceleration time in seconds #define TEND 240 #define TDELTA 2.0 // display timestep #define NSTARS 500 // background stars (this shows transparency) #define MOVE 0.3 // how much the background stars move #define LINETHICK 1 #define XSIZE 40*FSZ #define YSIZE 30*FSZ #define MINUTE 60 #define HOUR 3600 #include "gd.h" #include #include #include #include #include #define PI 3.14159265359 #define DEG2RAD(x) ((x)*PI/180.) // #define WIRING 1 // show solar cell wires gdImagePtr im; int black, white, gray, dgray, trans ; int xgauge = ( XSIZE + YSIZE ) / 2 ; // down the right edge double scale = SCALE * YSIZE ; // scale serversat in pixels // starting values double anglerad = 0.0 ; double time = 0.0 ; double angle_vel = 0.0 ; double angle_acc = 0.0 ; double angle = 0.0 ; double min_vel = 0.0 ; double max_vel = ACC * TIME1 / MINUTE ; double angle_min = 0.0 ; double angle_max = ACC * TIME1 * TIME1 / ( MINUTE * MINUTE ) ; double min_acc = -ACC ; double max_acc = ACC ; //-------------------------------------------------------------------- // fixed rectangle subroutines, swap order if needed // gdImageRectangle silently fails unless it gets left, bottom, right, top void RectE( gdImagePtr imm, double rx1, double ry1, double rx2, double ry2, int rcolor ) { if( rx1 < rx2 ) { if( ry1 < ry2 ) { gdImageRectangle( imm, rx1, ry1, rx2, ry2, rcolor ); } else { gdImageRectangle( imm, rx1, ry2, rx2, ry1, rcolor ); } } else { if( ry1 < ry2 ) { gdImageRectangle( imm, rx2, ry1, rx1, ry2, rcolor ); } else { gdImageRectangle( imm, rx2, ry2, rx1, ry1, rcolor ); } } } void RectF( gdImagePtr imm, double rx1, double ry1, double rx2, double ry2, int rcolor ) { if( rx1 < rx2 ) { if( ry1 < ry2 ) { gdImageFilledRectangle( imm, rx1, ry1, rx2, ry2, rcolor ); } else { gdImageFilledRectangle( imm, rx1, ry2, rx2, ry1, rcolor ); } } else { if( ry1 < ry2 ) { gdImageFilledRectangle( imm, rx2, ry1, rx1, ry2, rcolor ); } else { gdImageFilledRectangle( imm, rx2, ry2, rx1, ry1, rcolor ); } } } //-------------------------------------------------------------------- // rotation, transformation, scaling -------- // // This is very weak. I would love to be able to make multiple // rotations of a serversat along multiple axes. gdPoint sr( double inx, double iny, double inz ) { gdPoint retvar ; // rotate, IN ONE PLANE ONLY // z is into the plane, away from observer double rx = inx ; double ry = iny * cos( anglerad ) - inz * sin( anglerad ) ; double rz = iny * sin( anglerad ) + inz * cos( anglerad ) ; // depth transform - THIS IS PROBABLY INCORRECT double trx = rx*(1.0+rz/Z0) ; double try = ry*(1.0+rz/Z0) ; retvar.x = (int) ( 0.5*YSIZE + scale * trx ) ; retvar.y = (int) ( 0.5*YSIZE - scale * try ) ; return retvar; } // draw random star field and move it with time ---------------------------- // uses all globals // star array, overlaps right edge, unscaled double starx[NSTARS], stary[NSTARS]; void makestars() { int nstar ; for( nstar = 0 ; nstar < NSTARS ; nstar++ ) { starx[nstar] = drand48() * ( XSIZE + MOVE*TEND ) ; stary[nstar] = drand48() * YSIZE ; } } void drawstars() { int nstar, xs, ys ; for( nstar = 0 ; nstar < NSTARS ; nstar++ ) { xs = (int) ( starx[nstar] - MOVE*time ) ; ys = (int) stary[nstar] ; if ( xs < YSIZE ) { gdImageSetPixel( im, xs, ys, white); } } } // draw gauges --------------------------------- // uses globals #define YCLOCK (4*FSZ) #define YACC (10*FSZ) #define YVEL (16*FSZ) #define YANG (22*FSZ) #define F2 (4*FSZ/5) #define F4 (FSZ/4) #define RCLOCK (3*FSZ+8) #define SECHAND (3*FSZ) #define MINHAND1 (2*FSZ) #define MINHAND2 (2*FSZ+5) #define MINWID 40 int gleft = YSIZE + 2*FSZ ; int gright = XSIZE - 2*FSZ ; int gscale( double gvar, double gmin, double gmax ) { return ( (int) ( gleft + (gvar-gmin) * ( (double)(gright-gleft))/(gmax-gmin) ) ) ; } void drawgauges() { double wangle ; // working angle int cx1, cy1, cx2, cy2 ; char s[80]; int ic ; // clock at xgauge, 100 ----------------------------- gdImageArc( im, xgauge, YCLOCK, 2*RCLOCK, 2*RCLOCK, 0, 360, white ); // clock / 60 for( ic = 0; ic < 60 ; ic += 1 ) { wangle = PI * ic / 30 ; if ( ic%15 == 0 ) { cx1 = xgauge + (int)(0.5 + (RCLOCK-6)*sin(wangle)) ; cy1 = YCLOCK - (int)(0.5 + (RCLOCK-6)*cos(wangle)) ; } else if( ic%5 == 0 ) { cx1 = xgauge + (int)(0.5 + (RCLOCK-4)*sin(wangle)) ; cy1 = YCLOCK - (int)(0.5 + (RCLOCK-4)*cos(wangle)) ; } else { cx1 = xgauge + (int)(0.5 + (RCLOCK-2)*sin(wangle)) ; cy1 = YCLOCK - (int)(0.5 + (RCLOCK-2)*cos(wangle)) ; } cx2 = xgauge + (int)(0.5 + RCLOCK *sin(wangle) ) ; cy2 = YCLOCK - (int)(0.5 + RCLOCK *cos(wangle) ) ; gdImageLine( im, cx1, cy1, cx2, cy2, white ) ; } // second hand wangle = 2.0 * PI * time / MINUTE ; cx1 = xgauge+(int)(0.5 + SECHAND*sin(wangle) ) ; cy1 = YCLOCK-(int)(0.5 + SECHAND*cos(wangle) ) ; gdImageLine( im, xgauge, YCLOCK, cx1, cy1, white ) ; // minute hand (two strokes ) wangle = 2.0 * PI * (time + MINWID) / HOUR ; cx1 = xgauge+(int)(0.5 + MINHAND1*sin(wangle) ) ; cy1 = YCLOCK-(int)(0.5 + MINHAND1*cos(wangle) ) ; wangle = 2.0 * PI * (time ) / HOUR ; cx2 = xgauge+(int)(0.5 + MINHAND2*sin(wangle) ) ; cy2 = YCLOCK-(int)(0.5 + MINHAND2*cos(wangle) ) ; gdImageLine( im, xgauge, YCLOCK, cx1, cy1, white ) ; gdImageLine( im, cx2, cy2, cx1, cy1, white ); wangle = 2.0 * PI * (time - MINWID) / HOUR ; cx1 = xgauge+(int)(0.5 + MINHAND1*sin(wangle) ) ; cy1 = YCLOCK-(int)(0.5 + MINHAND1*cos(wangle) ) ; gdImageLine( im, cx2, cy2, cx1, cy1, white ); gdImageLine( im, xgauge, YCLOCK, cx1, cy1, white ) ; // text clock sprintf( s, "%3.0f secs", time ); gdImageStringFT( im, NULL, white, FNT, FSZ, 0.0, xgauge-2*FSZ, 9*FSZ, s ); // angular acceleration gauge ---------------- gdImageStringFT( im, NULL, white, FNT, FSZ, 0.0, YSIZE, YACC+2*FSZ-F4, "acceleration" ); gdImageStringFT( im, NULL, white, FNT, F2, 0.0, YSIZE, YACC+5*FSZ, "degrees/min^2" ); sprintf( s, "%3.0f", min_acc ); gdImageStringFT( im, NULL, white, FNT, FSZ, 0.0, YSIZE-FSZ, YACC+4*FSZ, s ); sprintf( s, "%2.0f", max_acc ); gdImageStringFT( im, NULL, white, FNT, FSZ, 0.0, gright+F4, YACC+4*FSZ, s ); cx1 = gscale( angle_acc, min_acc, max_acc ) ; cx2 = gscale( 0, min_acc, max_acc ) ; RectE( im, gleft, YACC+2*FSZ, gright, YACC+4*FSZ, white ); RectF( im, cx1, YACC+2*FSZ, cx2, YACC+4*FSZ, white ); // angular velocity gauge --------------------- gdImageStringFT( im, NULL, white, FNT, FSZ, 0.0, YSIZE, YVEL+2*FSZ-F4, "velocity" ); gdImageStringFT( im, NULL, white, FNT, F2, 0.0, YSIZE, YVEL+5*FSZ, "degrees/min" ); sprintf( s, "%2.0f", min_vel ); gdImageStringFT( im, NULL, white, FNT, FSZ, 0.0, YSIZE, YVEL+4*FSZ, s ); sprintf( s, "%2.0f", max_vel ); gdImageStringFT( im, NULL, white, FNT, FSZ, 0.0, gright+F4, YVEL+4*FSZ, s ); cx1 = gscale( angle_vel, min_vel, max_vel ) ; cx2 = gscale( 0, min_vel, max_vel ) ; RectE( im, gleft, YVEL+2*FSZ, gright, YVEL+4*FSZ, white ); RectF( im, cx1, YVEL+2*FSZ, cx2, YVEL+4*FSZ, white ); // angle gauge ------------------------------- gdImageStringFT( im, NULL, white, FNT, FSZ, 0.0, YSIZE, YANG+2*FSZ-F4, "angle" ); gdImageStringFT( im, NULL, white, FNT, F2, 0.0, YSIZE, YANG+5*FSZ, "degrees" ); sprintf( s, "%2.0f", angle_min ); gdImageStringFT( im, NULL, white, FNT, FSZ, 0.0, YSIZE, YANG+4*FSZ, s ); sprintf( s, "%2.0f", angle_max ); gdImageStringFT( im, NULL, white, FNT, FSZ, 0.0, gright+F4, YANG+4*FSZ, s ); cx1 = gscale( angle, angle_min, angle_max ) ; cx2 = gscale( 0, angle_min, angle_max ) ; RectE( im, gleft, YANG+2*FSZ, gright, YANG+4*FSZ, white ); RectF( im, cx1, YANG+2*FSZ, cx2, YANG+4*FSZ, white ); } // draw circle --------------------------------- // uses some globals // fill inner circle with area factor "fill" // draw outer circle with full radius // used for main solar cell, and thrusters #define NPTS 100 gdPoint pointsf[NPTS]; // filled circle points gdPoint pointse[NPTS]; // edge circle points void drawcircle( int color, double fill, double centerx, double centery, double radius ) { int cntr ; double dangle = (2.0 * PI)/( NPTS-1 ); double sradius = radius*sqrt(fill) ; double c, s; for( cntr=0 ; cntr < NPTS ; cntr++ ) { c = cos( dangle * cntr ) ; s = sin( dangle * cntr ) ; pointsf[cntr] = sr( centerx + sradius*c , centery + sradius*s, 0.0 ) ; pointse[cntr] = sr( centerx + radius*c , centery + radius*s, 0.0 ) ; } gdImageFilledPolygon( im, pointsf, NPTS, color ); gdImagePolygon( im, pointse, NPTS, color ); } // ---------------------------------------------------------------------------- // perpendicular arrow void arrow( int acolor, double acenterx, double acentery, double alength ) { gdPoint pointsa[8]; double xwid = 0.05*alength ; double xhead = 0.15*alength ; double zhead = 0.3*alength ; pointsa[0] = sr( acenterx, acentery, alength ); pointsa[1] = sr( acenterx+xhead, acentery, alength-zhead ); pointsa[2] = sr( acenterx+xwid, acentery, alength-zhead ); pointsa[3] = sr( acenterx+xwid, acentery, 0.0 ); pointsa[4] = sr( acenterx-xwid, acentery, 0.0 ); pointsa[5] = sr( acenterx-xwid, acentery, alength-zhead ); pointsa[6] = sr( acenterx-xhead, acentery, alength-zhead ); pointsa[7] = sr( acenterx, acentery, alength ); gdImageFilledPolygon( im, pointsa, 8, acolor ); } // ---------------------------------------------------------------------------- // cell wiring stuff // draw scalable rectangle void RectS( double scolor, double sx1, double sy1, double sx2, double sy2) { gdPoint pointss[5]; pointss[0] = sr( sx1, sy1, 0.0 ); pointss[1] = sr( sx2, sy1, 0.0 ); pointss[2] = sr( sx2, sy2, 0.0 ); pointss[3] = sr( sx1, sy2, 0.0 ); pointss[4] = sr( sx1, sy1, 0.0 ); gdImageFilledPolygon( im, pointss, 5, scolor ); } // draw cell wiring --------------------------------- // This draws a cheesy wiring grid on the front of the cell void drawcellwire( int wcolor, double widthspace, double centerx, double centery, double wsize ) { int icnt ; int nlines = (int) ( 0.6666666*wsize/widthspace-1.0 ) ; double vsize = widthspace*( 1.5*nlines ); // center bar RectS( wcolor, centerx-widthspace, centery-vsize, centerx+widthspace, centery+vsize ); // horizontal lines for( icnt=0 ; icnt<=nlines ; icnt++ ) { RectS( wcolor, -wsize+centerx, (3.0*icnt )*widthspace+centery-vsize, wsize+centerx, (3.0*icnt+1.0)*widthspace+centery-vsize ); } } // this draws dots on the upper left edge, useful for scaling sizes in // openoffice void lineofdots() { int ctr; for( ctr=0; ctr < XSIZE; ctr +=4 ) { gdImageSetPixel( im, ctr, 0, gray ); gdImageSetPixel( im, ctr, 1, gray ); gdImageSetPixel( im, 0, ctr, gray ); gdImageSetPixel( im, 1, ctr, gray ); } } //===================================================================== int main () { FILE *pngout; char comment[80] ; char dirname[80] ; char framename[80] ; double timem ; // time in minutes double t1, t2, t3 ; // thrust value for each cell int frame ; // frame count int npics ; // last frame count npics = (int) ( (double)(TEND/TDELTA) +0.5 ) ; makestars(); // make directory system( RMMKDIR ); for( frame = 0 ; frame <= npics ; frame++ ) { im = gdImageCreateTrueColor(XSIZE, YSIZE); white = gdImageColorAllocate (im, 255, 255, 255); black = gdImageColorAllocate (im, 0, 0, 0); gray = gdImageColorAllocate (im, 127, 127, 127); dgray = gdImageColorAllocate (im, 64, 64, 64); trans = gdImageColorAllocate (im, 1, 1, 1); time = TDELTA*( (double) frame ) ; // start out stopped, display for a while if( time <= 0.0 ) { angle_acc = 0.0 ; angle_vel = 0.0 ; angle = 0.0 ; t1 = 0.5 ; t2 = 0.5 ; t3 = 0.5 ; strcpy( comment, "stopped" ); } // accelerate between 0 seconds and TIME1 seconds else if( time < 1.0*TIME1 ) { timem = time/ MINUTE ; angle_acc = ACC ; angle_vel = ACC * timem ; angle = ACC * 0.5 * timem * timem ; t1 = 0.0 ; t2 = 0.0 ; t3 = 1.0 ; strcpy( comment, "accelerating" ); } // decelerate between TIME1 seconds and 2*TIME1 seconds else if( time < 2.0*TIME1 ) { timem = (2.0*TIME1-time)/ MINUTE ; angle_acc = -ACC ; angle_vel = ACC * timem ; angle = angle_max - ( 0.5 * ACC * timem * timem ); t1 = 1.0 ; t2 = 1.0 ; t3 = 0.0 ; strcpy( comment, "decelerating" ); } // end up stopped, display for a while else { angle_acc = 0.0 ; angle_vel = 0.0 ; angle = angle_max; t1 = 0.5 ; t2 = 0.5 ; t3 = 0.5 ; strcpy( comment, "stopped" ); } anglerad = DEG2RAD( angle ); lineofdots(); // calibration strips drawstars(); // draw stars drawgauges(); // draw gauges // draw serversat ----------------------------------------------- gdImageSetThickness( im, LINETHICK ); drawcircle( gray, 1.0, 0.0000, 0.0000, 3.0000 ); drawcircle( white, t1, -3.4641, 2.0000, 1.0000 ); drawcircle( white, t2, 3.4641, 2.0000, 1.0000 ); drawcircle( white, t3, 0.0000, -4.0000, 1.0000 ); #ifdef WIRING drawcellwire( gray, 0.10, 0.0000, 0.0000, 2.0000 ); #endif // WIRING // arrow and status text RectS( white, -4.5000, -0.0001, 4.5000, 0.0001 ) ; arrow( white, -4.0000, 0.0000, 2.0000 ) ; arrow( white, 4.0000, 0.0000, 2.0000 ) ; gdImageStringFT( im, NULL, white, FNT, 2*FSZ, 0.0, FSZ, 4*FSZ, comment ); // output frame to directory in PNG format sprintf( framename, PNGFMT , frame ); // sprintf( framename, PNGFMT ); pngout = fopen ( framename , "wb"); gdImagePngEx( im, pngout, 1 ); gdImageDestroy (im); fclose (pngout); // sprintf( framename, CONVERT, frame ); // system( framename ); // rescale image to antialias it } system( PNG2SWF ); }