Kontron KTAM3874-pITX - Manual (Page 147)

KTD-S0057-I Page 143 Linux® Programming Examples (DebianTM)
KTAM3874/pITX Software Guide
#define STAT_TXT
"Six cairo samples successfully drawn"
#define RGB_R(c) ((double)((c>>16)&255)/255.0)
#define RGB_G(c) ((double)((c>>8)&255)/255.0)
#define RGB_B(c) ((double)(c&255)/255.0)
#define C(c) (c.pixel)
#define HALF(x) (x/2.0)
#define QUART(x) (x/4.0)
#define FIFTH(x) (x/5.0)
#define TENTH(x) (x/10.0)
typedef struct {
Display
*disp;
Window win;
Colormap cmap;
Visual *visual;
int screen;
GC gc;
XFontStruct *font;
Pixmap pict;
Atom close;
} XSystem;
static void draw_cairo_object1 (XSystem sys, cairo_t *cr)
{
XColor
col;
double x0 = 0.0, y0 = 0.0,
width = OBJ_WIDTH,
height = OBJ_HEIGHT,
radius = HALF(OBJ_WIDTH),
x1 = x0 + width,
y1 = y0 + height;
cairo_save (cr);
cairo_move_to (cr, x0, y0 + radius);
cairo_curve_to (cr, x0 , y0, x0 , y0, x0 + radius, y0);
cairo_line_to (cr, x1 - radius, y0);
cairo_curve_to (cr, x1, y0, x1, y0, x1, y0 + radius);
cairo_line_to (cr, x1 , y1 - radius);
cairo_curve_to (cr, x1, y1, x1, y1, x1 - radius, y1);
cairo_line_to (cr, x0 + radius, y1);
cairo_curve_to (cr, x0, y1, x0, y1, x0, y1- radius);
cairo_close_path (cr);
XAllocNamedColor (sys.disp, sys.cmap, OBJ1_COL1, &col, &col);
cairo_set_source_rgb (cr, RGB_R (C(col)), RGB_G (C(col)), RGB_B (C(col)));
cairo_fill_preserve (cr);
XAllocNamedColor (sys.disp, sys.cmap, OBJ1_COL2, &col, &col);
cairo_set_source_rgba (cr, RGB_R (C(col)), RGB_G (C(col)), RGB_B (C(col)), ALPHA);
cairo_set_line_width (cr, LINE_WIDTH);
cairo_stroke (cr);
cairo_restore (cr);
}