DOS VGA, add VGA controller framebuffer
Jukka Heinonen
jhei at iki.fi
Mon Jul 29 11:41:34 CDT 2002
This patch makes it possible to implement VGA modes
that use bitplanes and unchained 256-color mode
(also called mode-x, I guess). Before this patch,
64k VGA window was directly copied to DirectDraw surface
which meant that only 256-color chained mode (0x13) had
any chance of working properly.
What is needed after this is routines that slice
parts of framebuffer into VGA window and merge VGA window
into framebuffer. I'm not going to implement this 100% correctly
because that would require emulating every single read/write to
VGA window. Perhaps later...
Changelog:
Add VGA controller framebuffer between
VGA window and DirectDrawSurface.
Index: vga.c
===================================================================
RCS file: /home/wine/wine/dlls/winedos/vga.c,v
retrieving revision 1.18
diff -u -r1.18 vga.c
--- vga.c 28 Jul 2002 17:42:30 -0000 1.18
+++ vga.c 29 Jul 2002 16:20:26 -0000
@@ -38,9 +38,39 @@
static LONG vga_refresh;
static HANDLE poll_timer;
-static int vga_width;
-static int vga_height;
-static int vga_depth;
+/*
+ * VGA controller memory is emulated using linear framebuffer.
+ * This frambuffer also acts as an interface
+ * between VGA controller emulation and DirectDraw.
+ *
+ * vga_fb_width: Display width in pixels. Can be modified when
+ * display mode is changed.
+ * vga_fb_height: Display height in pixels. Can be modified when
+ * display mode is changed.
+ * vga_fb_depth: Number of bits used to store single pixel color information.
+ * Each pixel uses (vga_fb_depth+7)/8 bytes because
+ * 1-16 color modes are mapped to 256 color mode.
+ * Can be modified when display mode is changed.
+ * vga_fb_pitch: How many bytes to add to pointer in order to move
+ * from one row to another. This is fixed in VGA modes,
+ * but can be modified in SVGA modes.
+ * vga_fb_offset: Offset added to framebuffer start address in order
+ * to find the display origin. Programs use this to do
+ * double buffering and to scroll display. The value can
+ * be modified in VGA and SVGA modes.
+ * vga_fb_size: How many bytes are allocated to framebuffer.
+ * VGA framebuffers are always larger than display size and
+ * SVGA framebuffers may also be.
+ * vga_fb_data: Pointer to framebuffer start.
+ */
+static int vga_fb_width;
+static int vga_fb_height;
+static int vga_fb_depth;
+static int vga_fb_pitch;
+static int vga_fb_offset;
+static int vga_fb_size = 0;
+static void *vga_fb_data = 0;
+
static BYTE vga_text_attr;
static char *textbuf_old = NULL;
@@ -343,10 +373,24 @@
int VGA_SetMode(unsigned Xres,unsigned Yres,unsigned Depth)
{
ModeSet par;
+ int newSize;
- vga_width = Xres;
- vga_height = Yres;
- vga_depth = Depth;
+ vga_fb_width = Xres;
+ vga_fb_height = Yres;
+ vga_fb_depth = Depth;
+ vga_fb_offset = 0;
+ vga_fb_pitch = Xres * ((Depth + 7) / 8);
+
+ newSize = Xres * Yres * ((Depth + 7) / 8);
+ if(newSize < 256 * 1024)
+ newSize = 256 * 1024;
+
+ if(vga_fb_size < newSize) {
+ if(vga_fb_data)
+ HeapFree(GetProcessHeap(), 0, vga_fb_data);
+ vga_fb_data = HeapAlloc(GetProcessHeap(), 0, newSize);
+ vga_fb_size = newSize;
+ }
if(Xres >= 640 || Yres >= 480) {
par.Xres = Xres;
@@ -710,6 +754,24 @@
/*** CONTROL ***/
+
+/*
+ * Copy part of VGA framebuffer to VGA window.
+ */
+static void VGA_CopyFrameToWindow(void)
+{
+ //FIXME: add implementation
+}
+
+/*
+ * Copy contents of VGA window to VGA framebuffer.
+ */
+static void VGA_CopyWindowToFrame(void)
+{
+ //FIXME: fix implementation
+ char *dat = DOSMEM_MapDosToLinear(0xa0000);
+ memmove(vga_fb_data, dat, 65536);
+}
/* FIXME: optimize by doing this only if the data has actually changed
* (in a way similar to DIBSection, perhaps) */
@@ -717,50 +779,32 @@
{
unsigned int Pitch, Height, Width, X, Y;
char *surf;
- char *dat = DOSMEM_MapDosToLinear(0xa0000);
+ char *dat = vga_fb_data + vga_fb_offset;
+ int bpp = (vga_fb_depth + 7) / 8;
surf = VGA_Lock(&Pitch,&Height,&Width,NULL);
if (!surf) return;
- if(vga_width == 320 && vga_depth <= 4)
- for (Y=0; Y<vga_height; Y++,surf+=Pitch*2,dat+=vga_width/8) {
- for(X=0; X<vga_width; X+=8) {
- int offset = X/8;
- int Z;
- for(Z=0; Z<8; Z++) {
- int b0 = (dat[offset] >> Z) & 0x1;
- int index = 7-Z;
- surf[(X+index)*2] = b0;
- surf[(X+index)*2+1] = b0;
- surf[(X+index)*2+Pitch] = b0;
- surf[(X+index)*2+Pitch+1] = b0;
- }
- }
- }
-
- if(vga_width == 320 && vga_depth == 8)
- for (Y=0; Y<vga_height; Y++,surf+=Pitch*2,dat+=vga_width) {
- for(X=0; X<vga_width; X++) {
- int b0 = dat[X];
- surf[X*2] = b0;
- surf[X*2+1] = b0;
- surf[X*2+Pitch] = b0;
- surf[X*2+Pitch+1] = b0;
- }
- }
-
- if(vga_depth <= 4)
- for (Y=0; Y<vga_height; Y++,surf+=Pitch,dat+=vga_width/8) {
- for(X=0; X<vga_width; X+=8) {
- int offset = X/8;
- int Z;
- for(Z=0; Z<8; Z++) {
- int b0 = (dat[offset] >> Z) & 0x1;
- int index = 7-Z;
- surf[X+index] = b0;
- }
+ /*
+ * Synchronize framebuffer contents.
+ */
+ VGA_CopyWindowToFrame();
+
+ /*
+ * Double VGA framebuffer (320x200 -> 640x400), if needed.
+ */
+ if(Height >= 2 * vga_fb_height && Width >= 2 * vga_fb_width && bpp == 1)
+ for (Y=0; Y<vga_fb_height; Y++,surf+=Pitch*2,dat+=vga_fb_pitch)
+ for (X=0; X<vga_fb_width; X++) {
+ BYTE value = dat[X];
+ surf[X*2] = value;
+ surf[X*2+1] = value;
+ surf[X*2+Pitch] = value;
+ surf[X*2+Pitch+1] = value;
}
- }
+ else
+ for (Y=0; Y<vga_fb_height; Y++,surf+=Pitch,dat+=vga_fb_pitch)
+ memcpy(surf, dat, vga_fb_width * bpp);
VGA_Unlock();
}
--
Jukka Heinonen <http://www.iki.fi/jhei/>
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