the rewrite branch builds, not tested yet

[dosdemo] / src / dos / gfx.c

diff --git a/src/dos/gfx.c b/src/dos/gfx.c
new file mode 100644 (file)
index 0000000..b55b4e6
--- /dev/null
+++ b/src/dos/gfx.c
@@ -0,0 +1,121 @@
+#include <stdio.h>
+#include "gfx.h"
+#include "vbe.h"
+#include "vga.h"
+#include "cdpmi.h"
+
+#ifdef __DJGPP__
+#include <sys/nearptr.h>
+#define REALPTR(s, o)  (void*)(((uint32_t)(s) << 4) - __djgpp_base_address + ((uint32_t)(o)))
+#else
+#define REALPTR(s, o)  (void*)(((uint32_t)(s) << 4) + ((uint32_t)(o)))
+#endif
+
+#define SAME_BPP(a, b)  \
+    ((a) == (b) || ((a) == 16 && (b) == 15) || ((a) == 15 && (b) == 16) || \
+     ((a) == 32 && (b) == 24) || ((a) == 24 && (b) == 32))
+
+static int vbe_init_ver;
+static struct vbe_info vbe;
+static int mode, pgsize, fbsize;
+static struct vbe_mode_info mode_info;
+
+static void *vpgaddr[2];
+static int fbidx;
+
+static int init_vbe(void)
+{
+       if(vbe_info(&vbe) == -1) {
+               return -1;
+       }
+
+       vbe_print_info(stdout, &vbe);
+       fflush(stdout);
+
+       vbe_init_ver = VBE_VER_MAJOR(vbe.ver);
+       return 0;
+}
+
+void *set_video_mode(int xsz, int ysz, int bpp)
+{
+       int i, nmodes;
+       int best_match_mode = -1;
+       struct vbe_mode_info minf;
+
+       if(!vbe_init_ver) {
+               if(init_vbe() == -1) {
+                       fprintf(stderr, "failed to initialize VBE\n");
+                       return 0;
+               }
+               if(vbe_init_ver < 2) {
+                       fprintf(stderr, "VBE >= 2.0 required\n");
+                       return 0;
+               }
+       }
+
+       mode = -1;
+
+       for(i=0; i<nmodes; i++) {
+               vbe_mode_info(vbe.modes[i], &minf);
+               if(minf.xres != xsz || minf.yres != ysz) continue;
+               if(minf.bpp == bpp) {
+                       mode = vbe.modes[i];
+                       break;
+               }
+               if(SAME_BPP(minf.bpp, bpp)) {
+                       best_match_mode = mode;
+               }
+       }
+
+       if(mode == -1) {
+               if(best_match_mode == -1) {
+                       fprintf(stderr, "failed to find requested video mode (%dx%d %d bpp)\n", xsz, ysz, bpp);
+                       return 0;
+               }
+               mode = best_match_mode;
+       }
+
+       vbe_mode_info(mode, &mode_info);
+       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) {
+               fprintf(stderr, "failed to set video mode\n");
+               return 0;
+       }
+
+       pgsize = mode_info.xres * mode_info.yres * (bpp / 8);
+       fbsize = mode_info.num_img_pages * pgsize;
+
+       vpgaddr[0] = (void*)dpmi_mmap(mode_info.fb_addr, fbsize);
+
+       if(mode_info.num_img_pages > 1) {
+               vpgaddr[1] = (char*)vpgaddr[0] + pgsize;
+               fbidx = 1;
+               page_flip(FLIP_NOW);    /* start with the second page visible */
+       } else {
+               fbidx = 0;
+               vpgaddr[1] = 0;
+       }
+
+       return vpgaddr[0];
+}
+
+int set_text_mode(void)
+{
+       vga_setmode(3);
+       return 0;
+}
+
+void *page_flip(int vsync)
+{
+       if(!vpgaddr[1]) {
+               /* page flipping not supported */
+               return vpgaddr[0];
+       }
+
+       vbe_swap(fbidx ? pgsize : 0, vsync ? VBE_SWAP_VBLANK : VBE_SWAP_NOW);
+       fbidx = (fbidx + 1) & 1;
+
+       return vpgaddr[fbidx];
+}