/**
* Draw a rectangle
*
* @param f Video frame
* @param x0 Origin X-position
* @param y0 Origin Y-position
* @param w Rectangle width
* @param h Rectangle height
* @param r Red color component
* @param g Green color component
* @param b Blue color component
*/
void vidframe_draw_rect(struct vidframe *f, unsigned x0, unsigned y0,
unsigned w, unsigned h,
uint8_t r, uint8_t g, uint8_t b)
{
if (!f)
return;
vidframe_draw_hline(f, x0, y0, w, r, g, b);
vidframe_draw_hline(f, x0, y0+h-1, w, r, g, b);
vidframe_draw_vline(f, x0, y0, h, r, g, b);
vidframe_draw_vline(f, x0+w-1, y0, h, r, g, b);
}
static void draw_graph(struct panel *panel, struct vidframe *frame)
{
uint64_t avg;
unsigned y0 = panel->yoffs;
size_t i;
if (rrd_get_average(panel, &avg))
return;
for (i=0; i<panel->rrdc; i++) {
uint64_t value;
double ratio;
unsigned pixels;
unsigned x = panel->xoffs + (unsigned)i * 2;
unsigned y;
value = panel->rrdv[i];
ratio = (double)value / (double)avg;
pixels = (double)panel->size.h * ratio * 0.5f;
pixels = min(pixels, panel->size.h);
y = y0 + panel->size.h - pixels;
vidframe_draw_vline(frame, x, y, pixels, 220, 220, 220);
}
}
static int plot_spectrum(const char *filename_png)
{
struct vidframe *vf = NULL;
struct vidsz sz = {NUM_FREQ+1, NUM_FREQ/2};
unsigned long peak_mag = 0;
size_t peak_bin = 0;
size_t i;
unsigned x;
int err;
err = vidframe_alloc(&vf, VID_FMT_RGB32, &sz);
if (err)
goto out;
/* find the peak amplitude and its bin */
for (i=0; i<NUM_FREQ; i++) {
if (magv[i] > peak_mag) {
peak_mag = magv[i];
peak_bin = i;
}
}
re_printf("peak magnitude is %u in bin %u\n", peak_mag, peak_bin);
vidframe_fill(vf, 255, 255, 255);
for (x=0; x<NUM_FREQ; x++) {
unsigned h;
h = (unsigned)((sz.h-1) * 1.0 * magv[x] / peak_mag);
vidframe_draw_vline(vf, x, sz.h-1-h, h, 255, 0, 0);
}
err = png_save_vidframe(vf, filename_png);
if (err)
goto out;
out:
mem_deref(vf);
return err;
}
