Add bitmap font to apple2, remove rectangle draw

include/apple2.h

@@ -3,6 +3,7 @@
 
 #include "apple2.dd.h"
 #include "mos6502.h"
+#include "vm_bitfont.h"
 #include "vm_screen.h"
 
 enum video_modes {
@@ -39,6 +40,12 @@ typedef struct {
      */
     vm_screen *screen;
 
+    /*
+     * This is the system font (the only font the Apple II knows about,
+     * really); anywhere we render text, we have to use this font.
+     */
+    vm_bitfont *sysfont;
+
     /*
      * This is the mode in which we must interpret graphics. This will
      * tell us not only if we're in lo- or hi-res, but also if we are in
@@ -68,6 +75,7 @@ extern void apple2_clear_strobe(apple2 *);
 extern void apple2_release_key(apple2 *);
 extern int apple2_boot(apple2 *);
 extern void apple2_run_loop(apple2 *);
+extern void apple2_set_color(apple2 *, int);
 extern void apple2_set_video(apple2 *, int);
 
 #endif

src/apple2.c

@@ -64,6 +64,16 @@ apple2_create(int width, int height)
     // We default to lo-res mode.
     apple2_set_video(mach, VIDEO_LORES);
 
+    // Let's install our bitmap font.
+    mach->sysfont = vm_bitfont_create(mach->screen,
+                                      "apple2-system",
+                                      7, 8,         // 7 pixels wide, 8 pixels tall
+                                      0x7f);        // 7-bit values only
+    if (mach->sysfont == NULL) {
+        log_critical("Could not initialize apple2: bad font");
+        return NULL;
+    }
+
     return mach;
 }
 
@@ -80,8 +90,6 @@ void
 apple2_run_loop(apple2 *mach)
 {
     while (vm_screen_active(mach->screen)) {
-        vm_screen_set_color(mach->screen, 255, 0, 0, 255);
-        vm_screen_draw_rect(mach->screen, 50, 50, 20, 20);
         vm_screen_refresh(mach->screen);
     }
 }

src/apple2.draw.c

@@ -10,4 +10,7 @@ apple2_draw_pixel(apple2 *mach, vm_16bit addr)
 void
 apple2_draw_text(apple2 *mach, vm_16bit addr)
 {
+    // Drawing text is a two-step process; first you need to wipe out
+    // the block on the screen at that point. Then you need to draw the
+    // text in over that.
 }