-/* celtic, Copyright (c) 2005 Max Froumentin <max@lapin-bleu.net>
+/* celtic, Copyright (c) 2006 Max Froumentin <max@lapin-bleu.net>
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* documentation. No representations are made about the suitability of this
* software for any purpose. It is provided "as is" without express or
* implied warranty.
+ *
+ * A celtic pattern programme inspired by "Les Entrelacs Celtes", by
+ * Christian Mercat, Dossier Pour La Science, no. 47, april/june 2005.
+ * See <http://www.entrelacs.net/>
*/
#include <math.h>
#include "screenhack.h"
#include "erase.h"
-#define SQRT3_2 .86602540378443864676
+#define SQRT_3 1.73205080756887729352
/*-----------------------------------------*/
Display *dpy;
unsigned long cluster_size; /* only used if type is kennicott */
unsigned long delay; /* controls curve drawing speed (step delay
* in microsecs) */
+ unsigned long nsteps; /* only if triangle: number of subdivisions along the side */
unsigned long nb_orbits; /* only used if type is polar */
unsigned long nb_nodes_per_orbit; /* only used if type is polar */
}
-
-static Graph make_triangle_graph(int xmin, int ymin, int width, int height, int step)
- /* make a simple grid graph */
+static Graph make_triangle_graph(int xmin, int ymin, int width, int height, int edge_size)
{
Graph g;
- int row,col,x,y;
- int size=width<height?width:height;
- int n=1+size/SQRT3_2/step;
Node *grid;
+ int row,col;
+ double L=(width<height?width:height)/2.0; /* circumradius of the triangle */
+ double cx=xmin+width/2.0, cy=ymin+height/2.0; /* centre of the triangle */
+ double p2x=cx-L*SQRT_3/2.0, p2y=cy+L/2.0; /* p2 is the bottom left vertex */
+ double x,y;
+ int nsteps=3*L/(SQRT_3*edge_size);
- assert(grid=(Node*)calloc(n*n,sizeof(Node)));
+ assert(grid=(Node*)calloc((nsteps+1)*(nsteps+1),sizeof(Node)));
assert(g=graph_new());
- /* adjust xmin and xmax so that the grid is centered */
- xmin+=(width-(n-1)*step)/2;
- ymin+=(height-SQRT3_2*(n-3)*step)/2;
-
/* create node grid */
- for (row=0;row<n;row++)
- for (col=0;col<n;col++)
- if (row+col<n) {
- x=col*step+xmin + row*step/2;
- y=SQRT3_2*row*step+ymin;
- grid[row+col*n]=node_new((double)x, (double)y);
- graph_add_node(g, grid[row+col*n]);
+ for (row=0;row<=nsteps;row++)
+ for (col=0;col<=nsteps;col++)
+ if (row+col<=nsteps) {
+ x=p2x+col*L*SQRT_3/nsteps + row*L*SQRT_3/(2*nsteps);
+ y=p2y-row*3*L/(2*nsteps);
+ grid[col+row*(nsteps+1)]=node_new((double)x, (double)y);
+ graph_add_node(g, grid[col+row*(nsteps+1)]);
}
/* create edges */
- for (row=0;row<n;row++)
- for (col=0;col<n;col++)
- if (row+col<n-1) {
- /* horizontal edges */
- graph_add_edge(g,edge_new(grid[row+col*n],grid[row+(col+1)*n]));
- /* vertical edges */
- graph_add_edge(g,edge_new(grid[row+col*n],grid[row+1+col*n]));
- /* diagonal edges */
- graph_add_edge(g,edge_new(grid[row+1+col*n],grid[row+(col+1)*n]));
+ for (row=0;row<nsteps;row++)
+ for (col=0;col<nsteps;col++)
+ if (row+col<nsteps) {
+ /* horizontal edges */
+ graph_add_edge(g,edge_new(grid[row+col*(nsteps+1)],grid[row+(col+1)*(nsteps+1)]));
+ /* vertical edges */
+ graph_add_edge(g,edge_new(grid[row+col*(nsteps+1)],grid[row+1+col*(nsteps+1)]));
+ /* diagonal edges */
+ graph_add_edge(g,edge_new(grid[row+1+col*(nsteps+1)],grid[row+(col+1)*(nsteps+1)]));
}
free(grid);
return g;
+
}
static Graph make_kennicott_graph(int xmin, int ymin, int width, int height, int step,
- int cluster_size)
+ int cluster_size)
/* make a graph inspired by one of the motifs from the Kennicott bible */
/* square grid of clusters of the shape /|\
* ---
for (row=0;row<nbrow;row++)
for (col=0;col<nbcol;col++) {
if (col!=nbcol-1)
- /* horizontal edge from edge 1 of cluster (row, col) to edge 3
- * of cluster (row,col+1) */
- graph_add_edge(g,edge_new(grid[5*(row+col*nbrow)+1],grid[5*(row+(col+1)*nbrow)+3]));
+ /* horizontal edge from edge 1 of cluster (row, col) to edge 3
+ * of cluster (row,col+1) */
+ graph_add_edge(g,edge_new(grid[5*(row+col*nbrow)+1],grid[5*(row+(col+1)*nbrow)+3]));
if (row!=nbrow-1)
- /* vertical edge from edge 4 of cluster (row, col) to edge 2
- * of cluster (row+1,col) */
- graph_add_edge(g,edge_new(grid[5*(row+col*nbrow)+4],
- grid[5*(row+1+col*nbrow)+2]));
+ /* vertical edge from edge 4 of cluster (row, col) to edge 2
+ * of cluster (row+1,col) */
+ graph_add_edge(g,edge_new(grid[5*(row+col*nbrow)+4],
+ grid[5*(row+1+col*nbrow)+2]));
}
free(grid);
return g;
}
static void spline_add_segment(Spline s,
- double x1, double y1, double x2, double y2,
- double x3, double y3, double x4, double y4)
+ double x1, double y1, double x2, double y2,
+ double x3, double y3, double x4, double y4)
{
SplineSegment ss=(SplineSegment)calloc(1,sizeof(struct spline_segment));
ss->x1=x1; ss->x2=x2; ss->x3=x3; ss->x4=x4;
for (i=0;i<s->segments->nb_elements;i++) {
ss=s->segments->elements[i];
fprintf(f," - segment %d: (%g, %g),(%g, %g),(%g, %g),(%g, %g)\n",
- i,ss->x1,ss->y1,ss->x2,ss->y2,ss->x3,ss->y3,ss->x4,ss->y4);
+ i,ss->x1,ss->y1,ss->x2,ss->y2,ss->x3,ss->y3,ss->x4,ss->y4);
}
}
#endif
}
static void pattern_draw_spline_direction(Pattern p, Spline s,
- Node node, Edge edge1, Edge edge2,
- Direction direction)
+ Node node, Edge edge1, Edge edge2,
+ Direction direction)
{
double x1=(edge1->node1->x+edge1->node2->x)/2.0;
double y1=(edge1->node1->y+edge1->node2->y)/2.0;
/* add the spline segment to the spline */
pattern_draw_spline_direction(p,s,current_node,
- current_edge,next_edge,current_direction);
+ current_edge,next_edge,current_direction);
/* cross the edge */
current_edge = next_edge;
int i,segment,unused;
int ticks = 0;
double step=0.0001; /* TODO: set the step (or the delay) as a
- * function of the spline length, so that
- * drawing speed is constant
- */
+ * function of the spline length, so that
+ * drawing speed is constant
+ */
Spline s;
XSetLineAttributes(dpy,gc,params.curve_width,LineSolid,CapRound,JoinRound);
for (t=0.0;t<1;t+=step) {
for (i=0;i<p->splines->nb_elements;i++)
if ((s=p->splines->elements[i])) { /* skip if one-point spline */
- spline_value_at(s, &x, &y, fmod(t,1.0),&segment);
- spline_value_at(s, &x2, &y2, fmod(t+step,1.0),&unused);
-
- /* look ahead for the shadow segment */
- t2=t+step;
- if (t2<=1.0) {
- spline_value_at(s, &x3, &y3, fmod(t2,1.0),&unused);
- while (t2+step<1.0 && (x3-x2)*(x3-x2)+(y3-y2)*(y3-y2) < params.shadow_width*params.shadow_width) {
- t2+=step;
- spline_value_at(s, &x3, &y3, fmod(t2,1.0),&unused);
- }
-
- spline_value_at(s, &x4, &y4, fmod(t2+step,1.0),&unused);
-
- /* draw shadow line */
- XDrawLine(dpy,window,shadow_gc,
- (int)rint(x3),(int)rint(y3),
- (int)rint(x4),(int)rint(y4));
- }
- /* draw line segment */
- if (p->splines->nb_elements==1)
- XSetForeground(dpy, gc, colors[segment%(ncolors-3)+2].pixel);
- else
- XSetForeground(dpy, gc, colors[s->color].pixel);
- XDrawLine(dpy,window,gc,
- (int)rint(x),(int)rint(y),
- (int)rint(x2),(int)rint(y2));
+ spline_value_at(s, &x, &y, fmod(t,1.0),&segment);
+ spline_value_at(s, &x2, &y2, fmod(t+step,1.0),&unused);
+
+ /* look ahead for the shadow segment */
+ t2=t+step;
+ if (t2<=1.0) {
+ spline_value_at(s, &x3, &y3, fmod(t2,1.0),&unused);
+ while (t2+step<1.0 && (x3-x2)*(x3-x2)+(y3-y2)*(y3-y2) < params.shadow_width*params.shadow_width) {
+ t2+=step;
+ spline_value_at(s, &x3, &y3, fmod(t2,1.0),&unused);
+ }
+
+ spline_value_at(s, &x4, &y4, fmod(t2+step,1.0),&unused);
+
+ /* draw shadow line */
+ XDrawLine(dpy,window,shadow_gc,
+ (int)rint(x3),(int)rint(y3),
+ (int)rint(x4),(int)rint(y4));
+ }
+ /* draw line segment */
+ if (p->splines->nb_elements==1)
+ XSetForeground(dpy, gc, colors[segment%(p->ncolors-3)+2].pixel);
+ else
+ XSetForeground(dpy, gc, colors[s->color].pixel);
+ XDrawLine(dpy,window,gc,
+ (int)rint(x),(int)rint(y),
+ (int)rint(x2),(int)rint(y2));
}
if (++ticks > 100) {
spline_value_at(s, &x2, &y2, fmod(t-offset,1.0),&unused);
while ((x2-x)*(x2-x)+(y2-y)*(y2-y) < params.shadow_width*params.shadow_width) {
- offset+=step;
- spline_value_at(s, &x2, &y2, fmod(t-offset,1.0),&unused);
+ offset+=step;
+ spline_value_at(s, &x2, &y2, fmod(t-offset,1.0),&unused);
}
XDrawLine(dpy,window,gc, (int)rint(x),(int)rint(y), (int)rint(x2),(int)rint(y2));
}
#endif
+#if 0
+static void colormap_to_s(int ncolors, XColor *colors)
+{
+ int i;
+ printf("-- colormap (%d colors):\n",ncolors);
+ for (i=0;i<ncolors;i++)
+ printf("%d: %d %d %d\n", i, colors[i].red, colors[i].green, colors[i].blue);
+ printf("----\n");
+}
+#endif
+
+
+
void screenhack(Display * d, Window w)
{
XGCValues gcv;
if (ncolors < 2)
goto MONO;
else {
- colors[0].pixel = get_pixel_resource("foreground", "Foreground",
- dpy, xgwa.colormap);
- colors[1].pixel = get_pixel_resource("background", "Background",
- dpy, xgwa.colormap);
+ colors[0].pixel = get_pixel_resource("foreground", "Foreground",
+ dpy, xgwa.colormap);
+ colors[1].pixel = get_pixel_resource("background", "Background",
+ dpy, xgwa.colormap);
}
}
-
-
+
/* graphic context for curves */
gcv.foreground = colors[0].pixel;
gcv.background = colors[1].pixel;
/*=======================================================*/
for (;;) {
-
params.curve_width=random()%5+4;
params.shadow_width=params.curve_width+4;
- params.shape1=(random()%20)/10.0 -1.0;
- params.shape2=(random()%20)/10.0 -1.0;
+ params.shape1=(15+random()%15)/10.0 -1.0;
+ params.shape2=(15+random()%15)/10.0 -1.0;
params.edge_size=10*(random()%5)+20;
params.delay=get_integer_resource("delay", "Delay");
params.angle=random()%360*2*M_PI/360;
+ params.margin=(random()%8)*100-600;
switch (random()%4) {
case 0:
params.type=grid;
- params.margin=(random()%30)*10;
+ params.shape1=(random()%1*2-1.0)*(random()%10+3)/10.0;
+ params.shape2=(random()%1*2-1.0)*(random()%10+3)/10.0;
+ params.edge_size=10*(random()%5)+50;
break;
case 1:
params.type=kennicott;
- params.edge_size=10*(random()%3)+50;
- params.cluster_size=params.edge_size/(2+random()%3)-1;
- params.margin=(random()%30)*10;
+ params.shape1=(random()%20)/10.0 -1.0;
+ params.shape2=(random()%20)/10.0 -1.0;
+ params.edge_size=10*(random()%3)+70;
+ params.cluster_size=params.edge_size/(3.0+random()%10)-1;
break;
case 2:
params.type=triangle;
- params.margin=(random()%10)*10;
+ params.edge_size=10*(random()%5)+60;
+ params.margin=(random()%10)*100-900;
break;
case 3:
params.type=polar;
- params.nb_orbits=2+random()%20;
- params.nb_nodes_per_orbit=4+random()%20;
- params.margin=(random()%10)*20-50;
+ params.nb_orbits=2+random()%10;
+ params.nb_nodes_per_orbit=4+random()%10;
break;
}
+
+
+/* params.type= polar; */
+/* params.nb_orbits= 5; */
+/* params.nb_nodes_per_orbit= 19; */
+/* params.curve_width= 4; */
+/* params.shadow_width= 8; */
+/* params.shape1= 0.5; */
+/* params.shape2= 1.3; */
+/* params.margin= 30; */
+/* params.angle= 5.21853; */
+/* params.delay= 10000; */
+
/* params_to_s(stdout); */
switch (params.type) {
case grid:
g=make_grid_graph(params.margin,params.margin,
- xgwa.width-2*params.margin,
- xgwa.height-2*params.margin,
- params.edge_size);
+ xgwa.width-2*params.margin,
+ xgwa.height-2*params.margin,
+ params.edge_size);
break;
case kennicott:
g=make_kennicott_graph(params.margin,params.margin,
- xgwa.width-2*params.margin,
- xgwa.height-2*params.margin,
- params.edge_size,
- params.cluster_size);
+ xgwa.width-2*params.margin,
+ xgwa.height-2*params.margin,
+ params.edge_size,
+ params.cluster_size);
break;
case triangle:
g=make_triangle_graph(params.margin,params.margin,
- xgwa.width-2*params.margin,
- xgwa.height-2*params.margin,
- params.edge_size);
+ xgwa.width-2*params.margin,
+ xgwa.height-2*params.margin,
+ params.edge_size);
break;
case polar:
g=make_polar_graph(params.margin,params.margin,
- xgwa.width-2*params.margin,
- xgwa.height-2*params.margin,
- params.nb_nodes_per_orbit,
- params.nb_orbits);
+ xgwa.width-2*params.margin,
+ xgwa.height-2*params.margin,
+ params.nb_nodes_per_orbit,
+ params.nb_orbits);
break;
default:
g=make_grid_graph(params.margin,params.margin,
- xgwa.width-2*params.margin,
- xgwa.height-2*params.margin,
- params.edge_size);
+ xgwa.width-2*params.margin,
+ xgwa.height-2*params.margin,
+ params.edge_size);
break;
}
erase_full_window(dpy,window);
/* recolor each time */
- {
- int ncolors = get_integer_resource ("ncolors", "Integer");
- if (ncolors > 2)
- make_smooth_colormap (dpy, xgwa.visual, xgwa.colormap,
- colors, &ncolors, True, 0, True);
- }
-
+ ncolors = get_integer_resource ("ncolors", "Integer");
+ if (ncolors > 2)
+ make_smooth_colormap (dpy, xgwa.visual, xgwa.colormap,
+ colors, &ncolors, True, 0, True);
}
}
projects / xscreensaver / blobdiff