scx/c/xlib/color.c

#include "xlib.h"
#include "scheme48.h"

s48_value scx_Create_Color(s48_value r, s48_value g, s48_value b) {
  s48_value col = S48_MAKE_VALUE(XColor);
  XColor* c = S48_EXTRACT_VALUE_POINTER(col, XColor);
  c->red = s48_extract_integer(r);
  c->green = s48_extract_integer(g);
  c->blue = s48_extract_integer(b);
  
  return col;
}

s48_value scx_Int_Extract_RGB_Values(XColor col) {
  s48_value res = S48_NULL;
  S48_DECLARE_GC_PROTECT(1);
  S48_GC_PROTECT_1(res);
  
  res = s48_cons( s48_enter_integer(col.blue), res );
  res = s48_cons( s48_enter_integer(col.green), res );
  res = s48_cons( s48_enter_integer(col.red), res );
  
  S48_GC_UNPROTECT();
  return res;
}

s48_value scx_Extract_RGB_Values(s48_value Xcolor) {
  return scx_Int_Extract_RGB_Values(*SCX_EXTRACT_COLOR(Xcolor));
}

s48_value scx_Query_Color (s48_value Xcolormap, s48_value Xpixel, 
			   s48_value Xdisplay) {
  XColor c;
  
  c.pixel = SCX_EXTRACT_PIXEL(Xpixel);
  XQueryColor(SCX_EXTRACT_DISPLAY(Xdisplay), 
	      SCX_EXTRACT_COLORMAP(Xcolormap), 
	      &c);
  
  return scx_Int_Extract_RGB_Values(c);
}


s48_value scx_Query_Colors(s48_value Xcolormap, s48_value Xpixels,
			   s48_value Xdisplay) {
  s48_value result = S48_FALSE;
  S48_DECLARE_GC_PROTECT(1);

  long n = S48_VECTOR_LENGTH(Xpixels);
  XColor p[n];
  int i;

  for (i=0; i < n; i++)
    p[i].pixel = SCX_EXTRACT_PIXEL(S48_VECTOR_REF(Xpixels, i));

  XQueryColors( SCX_EXTRACT_DISPLAY(Xdisplay), 
		SCX_EXTRACT_COLORMAP(Xcolormap), p, n );

  S48_GC_PROTECT_1(result);
  result = s48_make_vector(n, S48_FALSE);
  for (i=0; i < n; i++)
    S48_VECTOR_SET(result, i, scx_Int_Extract_RGB_Values(p[i]));

  S48_GC_UNPROTECT();
  return result;
}

s48_value scx_Lookup_Color(s48_value Xcolormap, s48_value Xdisplay,
			   s48_value color_name) {
  XColor visual, exact;
  
  s48_value res = S48_FALSE;
  S48_DECLARE_GC_PROTECT(1);

  if (XLookupColor( SCX_EXTRACT_DISPLAY(Xdisplay), 
		    SCX_EXTRACT_COLORMAP(Xcolormap), 
		    s48_extract_string(color_name), &visual, &exact )) {
    S48_GC_PROTECT_1(res);
    res = s48_cons( scx_Int_Extract_RGB_Values( visual ),
		    scx_Int_Extract_RGB_Values( exact ) );
  }

  S48_GC_UNPROTECT();
  return res;
}

void scx_init_color(void) {
  S48_EXPORT_FUNCTION(scx_Create_Color);
  S48_EXPORT_FUNCTION(scx_Extract_RGB_Values);
  S48_EXPORT_FUNCTION(scx_Query_Color);
  S48_EXPORT_FUNCTION(scx_Query_Colors);
  S48_EXPORT_FUNCTION(scx_Lookup_Color);
}