infcubes crashes

[dosdemo] / src / dos / gfx.c

diff --git a/src/dos/gfx.c b/src/dos/gfx.c
index 570eaba..8818ab9 100644 (file)
--- a/src/dos/gfx.c
+++ b/src/dos/gfx.c
@@ -22,6 +22,7 @@ static struct vbe_mode_info mode_info;
 
 static void *vpgaddr[2];
 static int fbidx;
+static int pgcount;
 
 static int init_vbe(void)
 {
@@ -50,7 +51,7 @@ static int init_vbe(void)
        return 0;
 }
 
-void *set_video_mode(int xsz, int ysz, int bpp)
+void *set_video_mode(int xsz, int ysz, int bpp, int nbuf)
 {
        int i, nmodes;
        int best_match_mode = -1;
@@ -70,7 +71,7 @@ void *set_video_mode(int xsz, int ysz, int bpp)
        mode = -1;
        nmodes = vbe_num_modes(&vbe);
        for(i=0; i<nmodes; i++) {
-               if(vbe_mode_info(vbe.modes[i], &minf) == -1) {
+               if(vbe_mode_info(vbe.modes[i] | VBE_MODE_LFB, &minf) == -1) {
                        continue;
                }
                if(minf.xres != xsz || minf.yres != ysz) continue;
@@ -95,17 +96,22 @@ void *set_video_mode(int xsz, int ysz, int bpp)
        printf("setting video mode %x: (%dx%d %d)\n", (unsigned int)mode, mode_info.xres,
                        mode_info.yres, mode_info.bpp);
 
-       if(vbe_setmode(mode) == -1) {
+       if(vbe_setmode(mode | VBE_MODE_LFB) == -1) {
                fprintf(stderr, "failed to set video mode\n");
                return 0;
        }
 
+       if(nbuf < 1) nbuf = 1;
+       if(nbuf > 2) nbuf = 2;
+       pgcount = nbuf > mode_info.num_img_pages ? mode_info.num_img_pages : nbuf;
+
        pgsize = mode_info.xres * mode_info.yres * (bpp / 8);
-       fbsize = mode_info.num_img_pages * pgsize;
+       fbsize = pgcount * pgsize;
 
        vpgaddr[0] = (void*)dpmi_mmap(mode_info.fb_addr, fbsize);
+       memset(vpgaddr[0], 0xaa, fbsize);
 
-       if(mode_info.num_img_pages > 1) {
+       if(pgcount > 1) {
                vpgaddr[1] = (char*)vpgaddr[0] + pgsize;
                fbidx = 1;
                page_flip(FLIP_NOW);    /* start with the second page visible */