Added Atari Lynx versions of three sample programs.

The Lynx target can't build the usual versions because its library doesn't have conio output and stdio.

samples/lynx/mandelbrot.c

@@ -0,0 +1,86 @@
+/*****************************************************************************\
+** mandelbrot sample program for Atari Lynx                                  **
+**                                                                           **
+** (w) 2002 by groepaz/hitmen, TGI support by Stefan Haubenthal              **
+\*****************************************************************************/
+
+
+
+#include <stdlib.h>
+#include <tgi.h>
+
+
+
+/* Graphics definitions */
+#define SCREEN_X        (tgi_getxres())
+#define SCREEN_Y        (tgi_getyres())
+#define MAXCOL          (tgi_getcolorcount())
+
+#define maxiterations   32
+#define fpshift         (10)
+#define tofp(_x)        ((_x)<<fpshift)
+#define fromfp(_x)      ((_x)>>fpshift)
+#define fpabs(_x)       (abs(_x))
+
+#define mulfp(_a,_b)    ((((signed long)_a)*(_b))>>fpshift)
+#define divfp(_a,_b)    ((((signed long)_a)<<fpshift)/(_b))
+
+/* Use static local variables for speed */
+#pragma static-locals (1);
+
+
+
+static void mandelbrot (signed short x1, signed short y1, signed short x2,
+                        signed short y2)
+{
+    /*  */
+    register signed short r, r1, i;
+    register signed short xs, ys, xx, yy;
+    register signed short x, y;
+    register unsigned char count;
+    register unsigned char maxcol = MAXCOL;
+
+    /* Calc stepwidth */
+    xs = ((x2 - x1) / (SCREEN_X));
+    ys = ((y2 - y1) / (SCREEN_Y));
+
+    yy = y1;
+    for (y = 0; y < (SCREEN_Y); y++) {
+        yy += ys;
+        xx = x1;
+        for (x = 0; x < (SCREEN_X); x++) {
+            xx += xs;
+            /* Do iterations */
+            r = 0;
+            i = 0;
+            for (count = 0; (count < maxiterations) &&
+                 (fpabs (r) < tofp (2)) && (fpabs (i) < tofp (2));
+                 ++count) {
+                r1 = (mulfp (r, r) - mulfp (i, i)) + xx;
+                /* i = (mulfp(mulfp(r,i),tofp(2)))+yy; */
+                i = (((signed long) r * i) >> (fpshift - 1)) + yy;
+                r = r1;
+            }
+            if (count == maxiterations) {
+                tgi_setcolor (0);
+            } else {
+                tgi_setcolor (count % maxcol);
+            }
+            /* Set pixel */
+            tgi_setpixel (x, y);
+        }
+    }
+}
+
+void main (void)
+{
+    /* Install the graphics driver */
+    tgi_install (tgi_static_stddrv);
+
+    /* Initialize graphics */
+    tgi_init ();
+    tgi_clear ();
+
+    /* Calc mandelbrot set */
+    mandelbrot (tofp (-2), tofp (-2), tofp (2), tofp (2));
+}