fallback to banked modes if LFB is not available

[eradicate] / src / dos / main.c

diff --git a/src/dos/main.c b/src/dos/main.c
index a41453b..c344df1 100644 (file)
--- a/src/dos/main.c
+++ b/src/dos/main.c
@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include "game.h"
 #include "keyb.h"
 #include "timer.h"
@@ -10,12 +11,16 @@
 static void draw(void);
 
 static struct video_mode *vmode;
-static void *vmem;
+
+static void swap_lfb(void *pixels);
+static void swap_banked(void *pixels);
+
 
 int main(int argc, char **argv)
 {
+       void *fb_buf;
        struct video_mode *vmodes;
-       int vmidx;
+       int vmidx, status = 0;
 
        init_logger("game.log");
 
@@ -35,9 +40,22 @@ int main(int argc, char **argv)
        }
        vmode = vmodes + vmidx;
 
+       if(vmode->fb_addr) {
+               swap_buffers = swap_lfb;
+       } else {
+               swap_buffers = swap_banked;
+       }
+
        fb_width = vmode->xsz;
        fb_height = vmode->ysz;
-       fb_size = (vmode->xsz * vmode->bpp / 8) * vmode->ysz;
+       fb_size = vmode->pitch * vmode->ysz;
+
+       if(!(fb_buf = malloc(fb_size + vmode->pitch * 2))) {
+               fprintf(stderr, "failed to allocate framebuffer\n");
+               status = -1;
+               goto break_evloop;
+       }
+       fb_pixels = (char*)fb_buf + vmode->pitch;
 
        reset_timer();
 
@@ -52,26 +70,52 @@ int main(int argc, char **argv)
        }
 
 break_evloop:
+       free(fb_buf);
        set_text_mode();
+       cleanup_video();
        kb_shutdown();
-       return 0;
+       return status;
 }
 
 static void draw(void)
 {
        int i, j;
-       uint16_t *pptr = vmem;
+       uint16_t *pptr = fb_pixels;
 
        for(i=0; i<fb_height; i++) {
                for(j=0; j<fb_width; j++) {
-                       int chess = (i >> 2) == (j >> 2);
+                       int chess = ((i >> 4) & 1) == ((j >> 4) & 1);
                        *pptr++ = chess ? 0xff00 : 0x00ff;
                }
        }
+
+       swap_buffers(fb_pixels);
 }
 
-void swap_buffers(void *pixels)
+static void swap_lfb(void *pixels)
 {
        wait_vsync();
        memcpy(vmem, pixels, fb_size);
 }
+
+static void swap_banked(void *pixels)
+{
+       int i, sz;
+       unsigned int pending;
+       unsigned char *pptr = pixels;
+       uint32_t offs = 0;
+
+       wait_vsync();
+
+       /* assume window is always at 0 at the beginning */
+       pending = fb_size;
+       while(pending > 0) {
+               sz = pending > vmode->bank_size ? vmode->bank_size : pending;
+               memcpy(vmem, pptr, sz);
+               pptr += sz;
+               pending -= sz;
+               vbe_setwin(0, ++offs);
+       }
+
+       vbe_setwin(0, 0);
+}