Fixed bug #84
authorSam Lantinga <slouken@libsdl.org>
Sun, 19 Mar 2006 12:04:40 +0000
changeset 1554 0ca607a5d173
parent 1553 63fa37538842
child 1555 780fd5b61df1
Fixed bug #84 Date: Sun, 23 Oct 2005 16:39:03 +0200 From: "A. Schmid" <sahib@phreaker.net> Subject: [SDL] no software surfaces with svgalib driver? Hi, I noticed that the SDL (1.2.9) svgalib driver only makes use of linear addressable (framebuffer) video modes. On older systems (like one of mine), linear addressable modes are often not available. Especially for cards with VESA VBE < 2.0 the svgalib vesa driver is unusable, since VESA only supports framebuffering for VBE 2.0 and later. The changes necessary to add support for software surfaces seem to be relatively small. I only had to hack src/video/svga/SDL_svgavideo.c (see attached patch). The code worked fine for me, but it is no more than a proof of concept and should be reviewed (probably has a memory leak when switching modes). It also uses the vgagl library (included in the svgalib package) and needs to be linked against it. -Alex
src/video/svga/SDL_svgavideo.c
--- a/src/video/svga/SDL_svgavideo.c	Sun Mar 19 10:48:48 2006 +0000
+++ b/src/video/svga/SDL_svgavideo.c	Sun Mar 19 12:04:40 2006 +0000
@@ -40,6 +40,7 @@
 #include <vga.h>
 #include <vgamouse.h>
 #include <vgakeyboard.h>
+#include <vgagl.h>
 
 #include "SDL_video.h"
 #include "SDL_mouse.h"
@@ -50,6 +51,8 @@
 #include "SDL_svgaevents_c.h"
 #include "SDL_svgamouse_c.h"
 
+static GraphicsContext *realgc = NULL;
+static GraphicsContext *virtgc = NULL;
 
 /* Initialization/Query functions */
 static int SVGA_VideoInit(_THIS, SDL_PixelFormat *vformat);
@@ -168,6 +171,9 @@
 		int i, j;
 
 		i = modeinfo->bytesperpixel-1;
+		if ( i < 0 ) {
+			return 0;
+		}
 		if ( actually_add ) {
 			SDL_Rect saved_rect[2];
 			int      saved_mode[2];
@@ -215,7 +221,7 @@
 	vga_modeinfo *modeinfo;
 
 	this->info.wm_available = 0;
-	this->info.hw_available = 1;
+	this->info.hw_available = (virtgc ? 0 : 1);
 	modeinfo = vga_getmodeinfo(vga_getcurrentmode());
 	this->info.video_mem = modeinfo->memory;
 	/* FIXME: Add hardware accelerated blit information */
@@ -268,7 +274,7 @@
 	total_modes = 0;
 	for ( mode=vga_lastmodenumber(); mode; --mode ) {
 		if ( vga_hasmode(mode) ) {
-			if ( SVGA_AddMode(this, mode, 0, 0) ) {
+			if ( SVGA_AddMode(this, mode, 0, 1) ) {
 				++total_modes;
 			}
 		}
@@ -302,7 +308,7 @@
 	}
 	for ( mode=vga_lastmodenumber(); mode; --mode ) {
 		if ( vga_hasmode(mode) ) {
-			SVGA_AddMode(this, mode, 1, 0);
+			SVGA_AddMode(this, mode, 1, 1);
 		}
 	}
 	SVGA_AddMode(this, G320x200x256, 1, 1);
@@ -344,6 +350,18 @@
 	vga_modeinfo *modeinfo;
 	int screenpage_len;
 
+	/* Clean up old video mode data */
+	if ( realgc ) {
+		free(realgc);
+		realgc = NULL;
+	}
+	if ( virtgc ) {
+		/* FIXME: Why does this crash?
+		gl_freecontext(virtgc);*/
+		free(virtgc);
+		virtgc = NULL;
+	}
+
 	/* Try to set the requested linear video mode */
 	bpp = (bpp+7)/8-1;
 	for ( mode=0; SDL_modelist[bpp][mode]; ++mode ) {
@@ -356,14 +374,22 @@
 		SDL_SetError("Couldn't find requested mode in list");
 		return(NULL);
 	}
-	vga_setmode(SDL_vgamode[bpp][mode]);
+	vgamode = SDL_vgamode[bpp][mode];
+	vga_setmode(vgamode);
 	vga_setpage(0);
 
-	vgamode=SDL_vgamode[bpp][mode];
-	if ((vga_setlinearaddressing()<0) && (vgamode!=G320x200x256)) {
-		SDL_SetError("Unable to set linear addressing");
-		return(NULL);
+	if ( (vga_setlinearaddressing() < 0) && (vgamode != G320x200x256) ) {
+		gl_setcontextvga(vgamode);
+		realgc = gl_allocatecontext();
+		gl_getcontext(realgc);
+    
+		gl_setcontextvgavirtual(vgamode);
+		virtgc = gl_allocatecontext();
+		gl_getcontext(virtgc);
+    
+		flags &= ~SDL_DOUBLEBUF;
 	}
+    
 	modeinfo = vga_getmodeinfo(SDL_vgamode[bpp][mode]);
 
 	/* Update hardware acceleration info */
@@ -379,7 +405,12 @@
 	}
 
 	/* Set up the new mode framebuffer */
-	current->flags = (SDL_FULLSCREEN|SDL_HWSURFACE);
+	current->flags = SDL_FULLSCREEN;
+	if ( virtgc ) {
+		current->flags |= SDL_SWSURFACE;
+	} else {
+		current->flags |= SDL_HWSURFACE;
+	}
 	if ( bpp == 8 ) {
 		/* FIXME: What about DirectColor? */
 		current->flags |= SDL_HWPALETTE;
@@ -387,7 +418,11 @@
 	current->w = width;
 	current->h = height;
 	current->pitch = modeinfo->linewidth;
-	current->pixels = vga_getgraphmem();
+	if ( virtgc ) {
+		current->pixels = virtgc->vbuf;
+	} else {
+		current->pixels = vga_getgraphmem();
+	}
 
 	/* set double-buffering */
 	if ( flags & SDL_DOUBLEBUF )
@@ -418,7 +453,11 @@
 	} 
 
 	/* Set the blit function */
-	this->UpdateRects = SVGA_DirectUpdate;
+	if ( virtgc ) {
+		this->UpdateRects = SVGA_BankedUpdate;
+	} else {
+		this->UpdateRects = SVGA_DirectUpdate;
+	}
 
 	/* Set up the mouse handler again (buggy SVGAlib 1.40) */
 	mouse_seteventhandler(SVGA_mousecallback);
@@ -450,10 +489,12 @@
 
 static int SVGA_FlipHWSurface(_THIS, SDL_Surface *surface)
 {
-	vga_setdisplaystart(flip_offset[flip_page]);
-	flip_page=!flip_page;
-	surface->pixels=flip_address[flip_page];
-	vga_waitretrace();
+	if ( !virtgc ) {
+		vga_setdisplaystart(flip_offset[flip_page]);
+		flip_page=!flip_page;
+		surface->pixels=flip_address[flip_page];
+		vga_waitretrace();
+	}
 	return(0);
 }
 
@@ -462,9 +503,15 @@
 	return;
 }
 
-/* FIXME: Can this be used under SVGAlib? */
 static void SVGA_BankedUpdate(_THIS, int numrects, SDL_Rect *rects)
 {
+	int i;
+	SDL_Rect *rect;
+
+	for ( i=0; i < numrects; ++i ) {
+		rect = &rects[i];
+		gl_copyboxtocontext(rect->x, rect->y, rect->w, rect->h, realgc, rect->x, rect->y);
+	}
 	return;
 }
 
@@ -490,6 +537,16 @@
 
 	/* Reset the console video mode */
 	if ( this->screen && (this->screen->w && this->screen->h) ) {
+		if ( realgc ) {
+			free(realgc);
+			realgc = NULL;
+		}
+		if ( virtgc ) {
+			/* FIXME: Why does this crash?
+			gl_freecontext(virtgc);*/
+			free(virtgc);
+			virtgc = NULL;
+		}
 		vga_setmode(TEXT);
 	}
 	keyboard_close();