X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=dosdemo;a=blobdiff_plain;f=src%2Fdos%2Fgfx.c;fp=src%2Fdos%2Fgfx.c;h=b55b4e6b3f28b7ad94400e35e00658537654f491;hp=0000000000000000000000000000000000000000;hb=b82bab85314bbc57d1c542d4d6687de0cd75c375;hpb=acf706a52fdef3bea3f4ae07b7797395f854c11e

diff --git a/src/dos/gfx.c b/src/dos/gfx.c
new file mode 100644
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];
+}