ref: 5a725b7c6a1c22800656f218e46b5b16b0d21884
dir: /vmodeled/main.c/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <thread.h>
#include <draw.h>
#include <mouse.h>
#include <keyboard.h>
#include <geometry.h>
typedef enum {
SLine,
SCurve,
NStrokes
} Stroke;
typedef enum {
Drawing,
Zooming,
Rotating,
Movingpts,
NStates
} State;
/*
* Vector model - made out of lines and curves
*/
typedef struct VModel VModel;
struct VModel
{
Point2 *pts;
ulong npts;
ulong cap;
/* WIP
* l(ine) → takes 2 points
* c(urve) → takes 3 points
*/
char *strokefmt;
};
typedef struct Object Object;
struct Object
{
RFrame;
VModel *mdl;
void (*scale)(Object*, double);
void (*rotate)(Object*, double);
};
char *strokename[NStrokes] = {
[SLine] "line",
[SCurve] "curve",
};
char *statename[NStates] = {
[Drawing] "drawing",
[Zooming] "zooming",
[Rotating] "rotating",
[Movingpts] "moving",
};
RFrame worldrf;
Object mainobj;
Stroke stroke;
State curstate;
Point2 ptstk[3];
Point2 *ptstkp;
char *vmdlfile;
Image *ptselcol, *guidecol;
void resized(void);
void*
emalloc(ulong n)
{
void *p;
p = malloc(n);
if(p == nil)
sysfatal("malloc: %r");
setmalloctag(p, getcallerpc(&n));
return p;
}
void*
erealloc(void *p, ulong n)
{
void *np;
np = realloc(p, n);
if(np == nil){
if(n == 0)
return nil;
sysfatal("realloc: %r");
}
if(p == nil)
setmalloctag(np, getcallerpc(&p));
else
setrealloctag(np, getcallerpc(&p));
return np;
}
Image*
eallocimage(Display *d, Rectangle r, ulong chan, int repl, ulong col)
{
Image *i;
i = allocimage(d, r, chan, repl, col);
if(i == nil)
sysfatal("allocimage: %r");
return i;
}
Point
toscreen(Point2 p)
{
p = invrframexform(p, worldrf);
return Pt(p.x,p.y);
}
Point2
fromscreen(Point p)
{
return rframexform(Pt2(p.x,p.y,1), worldrf);
}
void
obj_rotate(Object *o, double θ)
{
Matrix R = {
cos(θ), -sin(θ), 0,
sin(θ), cos(θ), 0,
0, 0, 1,
};
o->bx = xform(o->bx, R);
o->by = xform(o->by, R);
}
void
obj_scale(Object *o, double s)
{
o->bx = mulpt2(o->bx, s);
o->by = mulpt2(o->by, s);
}
VModel *
readvmodel(char *file)
{
ulong lineno;
char *s, *args[2];
Biobuf *bin;
VModel *mdl;
bin = Bopen(file, OREAD);
if(bin == nil)
sysfatal("Bopen: %r");
mdl = emalloc(sizeof(VModel));
mdl->pts = nil;
mdl->npts = mdl->cap = 0;
mdl->strokefmt = nil;
lineno = 0;
while(s = Brdline(bin, '\n')){
s[Blinelen(bin)-1] = 0;
lineno++;
switch(*s++){
case '#':
continue;
case 'v':
if(tokenize(s, args, nelem(args)) != nelem(args)){
werrstr("syntax error: %s:%lud 'v' expects %d args",
file, lineno, nelem(args));
free(mdl);
Bterm(bin);
return nil;
}
mdl->cap = ++mdl->npts;
mdl->pts = erealloc(mdl->pts, mdl->cap*sizeof(Point2));
mdl->pts[mdl->npts-1].x = strtod(args[0], nil);
mdl->pts[mdl->npts-1].y = strtod(args[1], nil);
mdl->pts[mdl->npts-1].w = 1;
break;
case 'l':
case 'c':
mdl->strokefmt = strdup(s-1);
break;
}
}
Bterm(bin);
return mdl;
}
int
writevmodel(VModel *mdl, char *file)
{
Point2 *p;
Biobuf *bout;
bout = Bopen(file, OWRITE);
if(bout == nil)
sysfatal("Bopen: %r");
for(p = mdl->pts; p < mdl->pts+mdl->npts; p++)
if(Bprint(bout, "v %g %g\n", p->x, p->y) == Beof)
goto saveerr;
if(Bprint(bout, "%s\n", mdl->strokefmt) == Beof){
saveerr:
Bterm(bout);
sysfatal("error saving model: %r");
}
Bterm(bout);
return 0;
}
void
drawvmodel(Image *dst, VModel *mdl)
{
int i;
char *s;
Point pts[3];
Point2 *p;
p = mdl->pts;
for(s = mdl->strokefmt; s != nil && p-mdl->pts < mdl->npts; s++)
switch(*s){
case 'l':
for(i = 0; i < nelem(pts)-1; i++)
pts[i] = toscreen(invrframexform(p[i], mainobj));
line(dst, pts[0], pts[1], 0, 0, 0, display->white, ZP);
for(i = 0; i < nelem(pts)-1; i++){
fillellipse(dst, pts[i], 2, 2, ptselcol, ZP);
draw(dst, rectaddpt(Rect(0,0,1,1), pts[i]), display->black, nil, ZP);
}
p += 2;
break;
case 'c':
for(i = 0; i < nelem(pts); i++)
pts[i] = toscreen(invrframexform(p[i], mainobj));
bezspline(dst, pts, nelem(pts), 0, 0, 0, display->white, ZP);
for(i = 0; i < nelem(pts); i++){
fillellipse(dst, pts[i], 2, 2, ptselcol, ZP);
draw(dst, rectaddpt(Rect(0,0,1,1), pts[i]), display->black, nil, ZP);
}
p += 3;
break;
}
}
void
drawaxes(void)
{
line(screen, toscreen(Pt2(0,512,1)), toscreen(Pt2(0,-512,1)), 0, 0, 0, display->white, ZP);
line(screen, toscreen(Pt2(512,0,1)), toscreen(Pt2(-512,0,1)), 0, 0, 0, display->white, ZP);
}
void
drawstrokepts(void)
{
Point2 *sp;
Point pt;
sp = ptstkp;
while(sp-- > ptstk){
pt = toscreen(invrframexform(*sp, mainobj));
fillellipse(screen, pt, 2, 2, guidecol, ZP);
draw(screen, rectaddpt(Rect(0,0,1,1), pt), display->black, nil, ZP);
}
}
void
drawinfo(void)
{
Point p;
char buf[128];
p = Pt(10,3);
snprint(buf, sizeof buf, "fmt %s", mainobj.mdl->strokefmt);
string(screen, addpt(screen->r.min, p), display->white, ZP, font, buf);
p.y += font->height;
snprint(buf, sizeof buf, "op %s", strokename[stroke]);
string(screen, addpt(screen->r.min, p), display->white, ZP, font, buf);
p.y += font->height;
snprint(buf, sizeof buf, "s %s", statename[curstate]);
string(screen, addpt(screen->r.min, p), display->white, ZP, font, buf);
}
void
drawguides(void)
{
Point p, hingepts[3];
Point2 hinge[3];
char buf[128];
double θ;
int i;
if(curstate == Rotating){
hinge[2] = Pt2(1,0,1);
hinge[2] = invrframexform(hinge[2], mainobj);
θ = atan2(hinge[2].y, hinge[2].x);
hinge[0] = Vec2(1,0);
hinge[2] = normvec2(Vec2(hinge[2].x,hinge[2].y));
hinge[1] = normvec2(divpt2(addpt2(hinge[0], hinge[2]), 2));
line(screen, toscreen(Pt2(0,0,1)), toscreen(addpt2(Pt2(0,0,1), mulpt2(hinge[2], 50))), 0, 0, 0, guidecol, ZP);
for(i = 0; i < nelem(hinge); i++)
hingepts[i] = toscreen(addpt2(Pt2(0,0,1), mulpt2(hinge[i], i&1? 25: 20)));
bezspline(screen, hingepts, nelem(hingepts), 0, 0, 0, guidecol, ZP);
p = toscreen(addpt2(Pt2(0,0,1), mulpt2(hinge[1], 50)));
snprint(buf, sizeof buf, "%g°", θ/DEG);
string(screen, p, guidecol, ZP, font, buf);
}
}
void
redraw(void)
{
lockdisplay(display);
draw(screen, screen->r, display->black, nil, ZP);
drawaxes();
drawvmodel(screen, mainobj.mdl);
drawstrokepts();
drawguides();
drawinfo();
flushimage(display, 1);
unlockdisplay(display);
}
void
undo(void)
{
VModel *mdl;
char *fmtp;
mdl = mainobj.mdl;
if(mdl->npts < 1)
return;
fmtp = &mdl->strokefmt[strlen(mdl->strokefmt)-1];
switch(*fmtp){
case 'l':
mdl->npts -= 2;
break;
case 'c':
mdl->npts -= 3;
break;
}
*fmtp = 0;
}
void
plot(Mousectl *mc, Keyboardctl *)
{
Point2 p;
VModel *mdl;
char *newfmt;
ulong fmtlen;
p = rframexform(fromscreen(mc->xy), mainobj);
mdl = mainobj.mdl;
if(ptstkp-ptstk < nelem(ptstk)){
*ptstkp++ = p;
switch(stroke){
case SLine:
if(ptstkp-ptstk == 2){
mdl->npts += 2;
if(mdl->npts > mdl->cap){
mdl->cap = mdl->npts;
mdl->pts = erealloc(mdl->pts, mdl->cap*sizeof(Point2));
}
mdl->pts[mdl->npts-2] = ptstk[0];
mdl->pts[mdl->npts-1] = ptstk[1];
ptstkp = &ptstk[0];
if(mdl->strokefmt == nil){
fmtlen = 2;
newfmt = emalloc(fmtlen);
}else{
fmtlen = strlen(mdl->strokefmt)+2;
newfmt = emalloc(fmtlen);
memmove(newfmt, mdl->strokefmt, fmtlen-2);
}
newfmt[fmtlen-2] = 'l';
newfmt[fmtlen-1] = 0;
free(mdl->strokefmt);
mdl->strokefmt = newfmt;
}
break;
case SCurve:
if(ptstkp-ptstk == 3){
mdl->npts += 3;
if(mdl->npts > mdl->cap){
mdl->cap = mdl->npts;
mdl->pts = erealloc(mdl->pts, mdl->cap*sizeof(Point2));
}
mdl->pts[mdl->npts-3] = ptstk[0];
mdl->pts[mdl->npts-2] = ptstk[1];
mdl->pts[mdl->npts-1] = ptstk[2];
ptstkp = &ptstk[0];
if(mdl->strokefmt == nil){
fmtlen = 2;
newfmt = emalloc(fmtlen);
}else{
fmtlen = strlen(mdl->strokefmt)+2;
newfmt = emalloc(fmtlen);
memmove(newfmt, mdl->strokefmt, fmtlen-2);
}
newfmt[fmtlen-2] = 'c';
newfmt[fmtlen-1] = 0;
free(mdl->strokefmt);
mdl->strokefmt = newfmt;
}
break;
}
}
}
void
movept(Mousectl *mc, Keyboardctl *)
{
Point2 p0, p1, *pp;
VModel *mdl;
p1 = fromscreen(mc->xy); /* screen to world */
mdl = mainobj.mdl;
for(pp = mdl->pts; pp < mdl->pts+mdl->npts; pp++){
p0 = invrframexform(*pp, mainobj); /* object to world */
if(vec2len(subpt2(p0, p1)) <= 2){
for(;;){
readmouse(mc);
if(mc->buttons != 1)
break;
*pp = rframexform(fromscreen(mc->xy), mainobj);
redraw();
}
break;
}
}
}
void
zoom(Mousectl *mc, Keyboardctl *)
{
double z; /* zooming factor */
Point oldxy, Δxy;
curstate = Zooming;
oldxy = mc->xy;
for(;;){
readmouse(mc);
if(mc->buttons != 2)
break;
Δxy = subpt(mc->xy, oldxy);
z = tanh((double)Δxy.y/100) + 1;
mainobj.scale(&mainobj, z);
oldxy = mc->xy;
redraw();
}
curstate = Drawing;
}
void
rota(Mousectl *mc, Keyboardctl *)
{
Point2 p;
double oldθ, θ;
curstate = Rotating;
p = rframexform(fromscreen(mc->xy), mainobj);
oldθ = atan2(p.y, p.x);
for(;;){
readmouse(mc);
if(mc->buttons != 4)
break;
p = rframexform(fromscreen(mc->xy), mainobj);
θ = atan2(p.y, p.x) - oldθ;
mainobj.rotate(&mainobj, θ);
redraw();
}
curstate = Drawing;
}
void
mouse(Mousectl *mc, Keyboardctl *kc)
{
if((mc->buttons & 1) != 0){
if(curstate == Drawing)
plot(mc, kc);
else if(curstate == Movingpts)
movept(mc, kc);
}
if((mc->buttons & 2) != 0)
zoom(mc, kc);
if((mc->buttons & 4) != 0)
rota(mc, kc);
}
void
key(Rune r)
{
switch(r){
case Kdel:
case 'q':
threadexitsall(nil);
case 'w':
writevmodel(mainobj.mdl, vmdlfile);
break;
case 'l':
stroke = SLine;
break;
case 'c':
stroke = SCurve;
break;
case 'm':
curstate = Movingpts;
break;
case 'd':
curstate = Drawing;
break;
case 'z':
undo();
break;
case Kesc:
ptstkp = &ptstk[0];
break;
}
}
void
usage(void)
{
fprint(2, "usage: %s file\n", argv0);
exits("usage");
}
void
threadmain(int argc, char *argv[])
{
Mousectl *mc;
Keyboardctl *kc;
Rune r;
GEOMfmtinstall();
ARGBEGIN{
default: usage();
}ARGEND;
if(argc != 1)
usage();
vmdlfile = argv[0];
if(newwindow(nil) < 0)
sysfatal("newwindow: %r");
if(initdraw(nil, nil, "vmodeled") < 0)
sysfatal("initdraw: %r");
if((mc = initmouse(nil, screen)) == nil)
sysfatal("initmouse: %r");
if((kc = initkeyboard(nil)) == nil)
sysfatal("initkeyboard: %r");
worldrf.p = Pt2(screen->r.min.x+Dx(screen->r)/2,screen->r.max.y-Dy(screen->r)/2,1);
worldrf.bx = Vec2(1, 0);
worldrf.by = Vec2(0,-1);
mainobj.bx = Vec2(1, 0);
mainobj.by = Vec2(0, 1);
mainobj.scale = obj_scale;
mainobj.rotate = obj_rotate;
mainobj.mdl = readvmodel(vmdlfile);
if(mainobj.mdl == nil)
sysfatal("readvmodel: %r");
ptstkp = &ptstk[0];
ptselcol = eallocimage(display, Rect(0,0,1,1), screen->chan, 1, DYellow);
guidecol = eallocimage(display, Rect(0,0,1,1), screen->chan, 1, DPalebluegreen);
display->locking = 1;
unlockdisplay(display);
redraw();
for(;;){
enum { MOUSE, RESIZE, KEYBOARD };
Alt a[] = {
{mc->c, &mc->Mouse, CHANRCV},
{mc->resizec, nil, CHANRCV},
{kc->c, &r, CHANRCV},
{nil, nil, CHANEND}
};
switch(alt(a)){
case MOUSE:
mouse(mc, kc);
break;
case RESIZE:
resized();
break;
case KEYBOARD:
key(r);
break;
}
redraw();
}
}
void
resized(void)
{
lockdisplay(display);
if(getwindow(display, Refnone) < 0)
sysfatal("couldn't resize");
unlockdisplay(display);
worldrf.p = Pt2(screen->r.min.x+Dx(screen->r)/2,screen->r.max.y-Dy(screen->r)/2,1);
redraw();
}