71 lines
1.6 KiB
C
71 lines
1.6 KiB
C
|
#include <stdio.h>
|
||
|
|
#include <cairo.h>
|
||
|
|
#define M_PI 3.14159265358979323846
|
||
|
|
|
||
|
|
static double width, height;
|
||
|
|
static char path_output[512];
|
||
|
|
static cairo_t *cr;
|
||
|
|
static cairo_surface_t *surface;
|
||
|
|
|
||
|
|
struct rgb {
|
||
|
|
double r, g, b;
|
||
|
|
} values[] = {
|
||
|
|
{0, .7, .9},
|
||
|
|
{.5, .9, .5},
|
||
|
|
{1., 1., .4},
|
||
|
|
{1., .8, .5},
|
||
|
|
{1., .6, .65},
|
||
|
|
{1., .4, .9},
|
||
|
|
};
|
||
|
|
#define NVALUES 6
|
||
|
|
|
||
|
|
int start = 0;
|
||
|
|
|
||
|
|
void lain_rainbow(cairo_t * cr) {
|
||
|
|
unsigned ii, jj;
|
||
|
|
double dy, dx, x0, y0, x1, y1, red, green, blue;
|
||
|
|
|
||
|
|
/* Outer black border */
|
||
|
|
red = green = blue = 1.;
|
||
|
|
cairo_set_line_width(cr, 0);
|
||
|
|
cairo_set_source_rgba(cr, red, green, blue, 1.);
|
||
|
|
|
||
|
|
cairo_rectangle(cr, 0, 0, width, height);
|
||
|
|
cairo_fill(cr);
|
||
|
|
|
||
|
|
/* Colors */
|
||
|
|
x1 = width;
|
||
|
|
dx = width / 36;
|
||
|
|
y1 = dy = height / 36;
|
||
|
|
x0 = 0;
|
||
|
|
y0 = 0;
|
||
|
|
for (ii = start, jj = 0; jj < 36; jj++, ii++) {
|
||
|
|
cairo_rectangle(cr, x0, y0, x1, y1);
|
||
|
|
cairo_set_source_rgba(cr, values[ii % NVALUES].r, values[ii % NVALUES].g, values[ii % NVALUES].b, 1.);
|
||
|
|
cairo_fill(cr);
|
||
|
|
y0 += dy;
|
||
|
|
x1 += dx;
|
||
|
|
y1 += dy;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
int main(int argc, char **argv) {
|
||
|
|
int n;
|
||
|
|
width = 3840;
|
||
|
|
height = 2160;
|
||
|
|
sprintf (path_output, "stage1-00.png");
|
||
|
|
if (argc == 2) {
|
||
|
|
n = 0;
|
||
|
|
sscanf(argv[1], "%d", &n);
|
||
|
|
start = n;
|
||
|
|
sprintf (path_output, "stage1-%02d.png", n);
|
||
|
|
}
|
||
|
|
surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, width, height);
|
||
|
|
cr = cairo_create(surface);
|
||
|
|
lain_rainbow(cr);
|
||
|
|
cairo_surface_write_to_png (surface, path_output);
|
||
|
|
cairo_surface_destroy(surface);
|
||
|
|
cairo_destroy(cr);
|
||
|
|
return 0;
|
||
|
|
}
|