4 files changed, 132 insertions, 113 deletions

diff --git a/src/mesa/drivers/x11/xm_api.c b/src/mesa/drivers/x11/xm_api.c
index ad9756bb90c..86395b7778a 100644
--- a/src/mesa/drivers/x11/xm_api.c
+++ b/src/mesa/drivers/x11/xm_api.c
@@ -196,10 +196,11 @@ static int mesaHandleXError( XMesaDisplay *dpy, XErrorEvent *event )
  *          1 = shared XImage support available
  *          2 = shared Pixmap support available also
  */
-#ifndef XFree86Server
 static int check_for_xshm( XMesaDisplay *display )
 {
-#ifdef USE_XSHM
+#if defined(XFree86Server)
+   return 0;
+#elif defined(USE_XSHM)
    int major, minor, ignore;
    Bool pixmaps;
 
@@ -215,11 +216,10 @@ static int check_for_xshm( XMesaDisplay *display )
       return 0;
    }
 #else
-   /* Can't compile XSHM support */
+   /* No  XSHM support */
    return 0;
 #endif
 }
-#endif
 
 
 /*
@@ -347,31 +347,24 @@ alloc_xmesa_buffer(XMesaVisual vis, BufferType type, XMesaColormap cmap)
 
       _mesa_initialize_framebuffer(&b->mesa_buffer, &vis->mesa_visual);
 
-      /* determine back buffer implementation */
-      if (vis->mesa_visual.doubleBufferMode) {
-         if (vis->ximage_flag) {
-            b->db_state = BACK_XIMAGE;
-         }
-         else {
-            b->db_state = BACK_PIXMAP;
-         }
-      }
-      else {
-         b->db_state = 0;
-      }
-
       /* Allocate the framebuffer's renderbuffers */
       assert(!b->mesa_buffer.Attachment[BUFFER_FRONT_LEFT].Renderbuffer);
       assert(!b->mesa_buffer.Attachment[BUFFER_BACK_LEFT].Renderbuffer);
 
       /* front renderbuffer */
-      b->frontxrb = xmesa_new_renderbuffer(NULL, 0, vis->mesa_visual.rgbMode);
+      b->frontxrb = xmesa_new_renderbuffer(NULL, 0, vis->mesa_visual.rgbMode,
+                                           GL_FALSE);
       _mesa_add_renderbuffer(&b->mesa_buffer, BUFFER_FRONT_LEFT,
                              &b->frontxrb->Base);
 
       /* back renderbuffer */
       if (vis->mesa_visual.doubleBufferMode) {
-         b->backxrb =xmesa_new_renderbuffer(NULL, 0, vis->mesa_visual.rgbMode);
+         b->backxrb = xmesa_new_renderbuffer(NULL, 0,
+                                             vis->mesa_visual.rgbMode,
+                                             GL_TRUE);
+         /* determine back buffer implementation */
+         b->db_mode = vis->ximage_flag ? BACK_XIMAGE : BACK_PIXMAP;
+
          _mesa_add_renderbuffer(&b->mesa_buffer, BUFFER_BACK_LEFT,
                                 &b->backxrb->Base);
       }
@@ -472,22 +465,6 @@ static void copy_colortable_info(XMesaBuffer dst, const XMesaBuffer src)
 /**********************************************************************/
 
 
-/*
- * Return number of bits set in n.
- */
-static int bitcount( unsigned long n )
-{
-   int bits;
-   for (bits=0; n>0; n=n>>1) {
-      if (n&1) {
-         bits++;
-      }
-   }
-   return bits;
-}
-
-
-
 /**
  * Allocate a shared memory XImage back buffer for the given XMesaBuffer.
  * Return:  GL_TRUE if success, GL_FALSE if error
@@ -605,7 +582,7 @@ xmesa_alloc_back_buffer( XMesaBuffer b, GLuint width, GLuint height )
    if (width == 0 || height == 0)
       return;
 
-   if (b->db_state == BACK_XIMAGE) {
+   if (b->db_mode == BACK_XIMAGE) {
       /* Deallocate the old backxrb->ximage, if any */
       if (b->backxrb->ximage) {
 #if defined(USE_XSHM) && !defined(XFree86Server)
@@ -622,10 +599,9 @@ xmesa_alloc_back_buffer( XMesaBuffer b, GLuint width, GLuint height )
 
       /* Allocate new back buffer */
 #ifdef XFree86Server
-      {
-	 /* Allocate a regular XImage for the back buffer. */
-	 b->backxrb->ximage = XMesaCreateImage(b->xm_visual->BitsPerPixel,
-					 width, height, NULL);
+      /* Allocate a regular XImage for the back buffer. */
+      b->backxrb->ximage = XMesaCreateImage(b->xm_visual->BitsPerPixel,
+                                            width, height, NULL);
 #else
       if (b->shm == 0 || !alloc_shm_back_buffer(b, width, height)) {
 	 /* Allocate a regular XImage for the back buffer. */
@@ -641,7 +617,7 @@ xmesa_alloc_back_buffer( XMesaBuffer b, GLuint width, GLuint height )
 	    _mesa_warning(NULL, "alloc_back_buffer: XCreateImage failed.");
 	 }
          b->backxrb->ximage->data = (char *) MALLOC( b->backxrb->ximage->height
-                                             * b->backxrb->ximage->bytes_per_line );
+                                        * b->backxrb->ximage->bytes_per_line );
          if (!b->backxrb->ximage->data) {
             _mesa_warning(NULL, "alloc_back_buffer: MALLOC failed.");
             XMesaDestroyImage( b->backxrb->ximage );
@@ -651,7 +627,7 @@ xmesa_alloc_back_buffer( XMesaBuffer b, GLuint width, GLuint height )
       b->backxrb->pixmap = None;
       b->backxrb->ximage = b->backxrb->ximage;
    }
-   else if (b->db_state==BACK_PIXMAP) {
+   else if (b->db_mode == BACK_PIXMAP) {
       if (!width)
          width = 1;
       if (!height)
@@ -662,9 +638,10 @@ xmesa_alloc_back_buffer( XMesaBuffer b, GLuint width, GLuint height )
 	 XMesaFreePixmap( b->xm_visual->display, b->backxrb->pixmap );
       }
       /* Allocate new back pixmap */
-      b->backxrb->pixmap = XMesaCreatePixmap( b->xm_visual->display, b->frontxrb->pixmap,
-					 width, height,
-					 GET_VISUAL_DEPTH(b->xm_visual) );
+      b->backxrb->pixmap = XMesaCreatePixmap( b->xm_visual->display,
+                                              b->frontxrb->pixmap,
+                                              width, height,
+                                              GET_VISUAL_DEPTH(b->xm_visual) );
       b->backxrb->ximage = NULL;
    }
 }
@@ -1070,9 +1047,9 @@ static void setup_truecolor( XMesaVisual v, XMesaBuffer buffer,
           3*16, 11*16,  1*16,  9*16,
          15*16,  7*16, 13*16,  5*16,
       };
-      GLint rBits = bitcount(rmask);
-      GLint gBits = bitcount(gmask);
-      GLint bBits = bitcount(bmask);
+      GLint rBits = _mesa_bitcount(rmask);
+      GLint gBits = _mesa_bitcount(gmask);
+      GLint bBits = _mesa_bitcount(bmask);
       GLint maxBits;
       GLuint i;
 
@@ -1286,9 +1263,7 @@ static GLboolean initialize_visual_and_buffer( int client,
       /* Setup for single/double buffering */
       if (v->mesa_visual.doubleBufferMode) {
          /* Double buffered */
-#ifndef XFree86Server
          b->shm = check_for_xshm( v->display );
-#endif
          xmesa_alloc_back_buffer(b, b->mesa_buffer.Width, b->mesa_buffer.Height);
       }
 
@@ -1315,9 +1290,9 @@ static GLboolean initialize_visual_and_buffer( int client,
 #ifdef XFree86Server
       b->swapgc = CreateScratchGC(v->display, window->depth);
       {
-	  CARD32 v[1];
-	  v[0] = FALSE;
-	  dixChangeGC(NullClient, b->swapgc, GCGraphicsExposures, v, NULL);
+         CARD32 v[1];
+         v[0] = FALSE;
+         dixChangeGC(NullClient, b->swapgc, GCGraphicsExposures, v, NULL);
       }
 #else
       gcvalues.graphics_exposures = False;
@@ -1592,9 +1567,9 @@ XMesaVisual XMesaCreateVisual( XMesaDisplay *display,
    {
       const int xclass = v->mesa_visual.visualType;
       if (xclass==GLX_TRUE_COLOR || xclass==GLX_DIRECT_COLOR) {
-         red_bits   = bitcount(GET_REDMASK(v));
-         green_bits = bitcount(GET_GREENMASK(v));
-         blue_bits  = bitcount(GET_BLUEMASK(v));
+         red_bits   = _mesa_bitcount(GET_REDMASK(v));
+         green_bits = _mesa_bitcount(GET_GREENMASK(v));
+         blue_bits  = _mesa_bitcount(GET_BLUEMASK(v));
          alpha_bits = 0;
       }
       else {
@@ -1691,13 +1666,13 @@ XMesaContext XMesaCreateContext( XMesaVisual v, XMesaContext share_list )
    _mesa_enable_2_0_extensions(mesaCtx);
 #if ENABLE_EXT_texure_compression_s3tc
     if (c->Mesa_DXTn) {
-       _mesa_enable_extension(c, "GL_EXT_texture_compression_s3tc");
-       _mesa_enable_extension(c, "GL_S3_s3tc");
+       _mesa_enable_extension(mesaCtx, "GL_EXT_texture_compression_s3tc");
+       _mesa_enable_extension(mesaCtx, "GL_S3_s3tc");
     }
-    _mesa_enable_extension(c, "GL_3DFX_texture_compression_FXT1");
+    _mesa_enable_extension(mesaCtx, "GL_3DFX_texture_compression_FXT1");
 #endif
 #if ENABLE_EXT_timer_query
-    _mesa_enable_extension(c, "GL_EXT_timer_query");
+    _mesa_enable_extension(mesaCtx, "GL_EXT_timer_query");
 #endif
 
    /* finish up xmesa context initializations */
@@ -2316,13 +2291,18 @@ void XMesaSwapBuffers( XMesaBuffer b )
 {
    GET_CURRENT_CONTEXT(ctx);
 
+   if (!b->backxrb) {
+      /* single buffered */
+      return;
+   }
+
    /* If we're swapping the buffer associated with the current context
     * we have to flush any pending rendering commands first.
     */
    if (ctx && ctx->DrawBuffer == &(b->mesa_buffer))
       _mesa_notifySwapBuffers(ctx);
 
-   if (b->db_state) {
+   if (b->db_mode) {
 #ifdef FX
       if (b->FXctx) {
          fxMesaSwapBuffers();
@@ -2389,7 +2369,12 @@ void XMesaCopySubBuffer( XMesaBuffer b, int x, int y, int width, int height )
    if (ctx && ctx->DrawBuffer == &(b->mesa_buffer))
       _mesa_notifySwapBuffers(ctx);
 
-   if (b->db_state) {
+   if (!b->backxrb) {
+      /* single buffered */
+      return; 
+   }
+
+   if (b->db_mode) {
       int yTop = b->mesa_buffer.Height - y - height;
 #ifdef FX
       if (b->FXctx) {
@@ -2448,9 +2433,11 @@ GLboolean XMesaGetBackBuffer( XMesaBuffer b,
                               XMesaPixmap *pixmap,
                               XMesaImage **ximage )
 {
-   if (b->db_state) {
-      if (pixmap)  *pixmap = b->backxrb->pixmap;
-      if (ximage)  *ximage = b->backxrb->ximage;
+   if (b->db_mode) {
+      if (pixmap)
+         *pixmap = b->backxrb->pixmap;
+      if (ximage)
+         *ximage = b->backxrb->ximage;
       return GL_TRUE;
    }
    else {
diff --git a/src/mesa/drivers/x11/xm_buffer.c b/src/mesa/drivers/x11/xm_buffer.c
index 593ac2bb19c..5db0b496c73 100644
--- a/src/mesa/drivers/x11/xm_buffer.c
+++ b/src/mesa/drivers/x11/xm_buffer.c
@@ -42,16 +42,44 @@ xmesa_delete_renderbuffer(struct gl_renderbuffer *rb)
 
 
 /**
- * Reallocate renderbuffer storage.
- * This is called when the window's resized.  It'll get called once for
- * the front color renderbuffer and again for the back color renderbuffer.
+ * Reallocate renderbuffer storage for front color buffer.
  */
 static GLboolean
-xmesa_alloc_storage(GLcontext *ctx, struct gl_renderbuffer *rb,
-                    GLenum internalFormat, GLuint width, GLuint height)
+xmesa_alloc_front_storage(GLcontext *ctx, struct gl_renderbuffer *rb,
+                          GLenum internalFormat, GLuint width, GLuint height)
 {
    struct xmesa_renderbuffer *xrb = (struct xmesa_renderbuffer *) rb;
 
+   /* just clear these to be sure we don't accidentally use them */
+   xrb->origin1 = NULL;
+   xrb->origin2 = NULL;
+   xrb->origin4 = NULL;
+
+   /* for the FLIP macro: */
+   xrb->bottom = height - 1;
+
+   rb->Width = width;
+   rb->Height = height;
+   rb->InternalFormat = internalFormat;
+
+   return GL_TRUE;
+}
+
+
+/**
+ * Reallocate renderbuffer storage for back color buffer.
+ * XXX we should resize the back pixmap/ximage here.
+ */
+static GLboolean
+xmesa_alloc_back_storage(GLcontext *ctx, struct gl_renderbuffer *rb,
+                         GLenum internalFormat, GLuint width, GLuint height)
+{
+   struct xmesa_renderbuffer *xrb = (struct xmesa_renderbuffer *) rb;
+
+   /* same as front buffer */
+   (void) xmesa_alloc_front_storage(ctx, rb, internalFormat, width, height);
+
+   /* plus... */
    if (xrb->ximage) {
       /* Needed by PIXELADDR1 macro */
       xrb->width1 = xrb->ximage->bytes_per_line;
@@ -73,19 +101,13 @@ xmesa_alloc_storage(GLcontext *ctx, struct gl_renderbuffer *rb,
       assert(xrb->pixmap);
    }
 
-   /* for the FLIP macro: */
-   xrb->bottom = height - 1;
-
-   rb->Width = width;
-   rb->Height = height;
-   rb->InternalFormat = internalFormat;
-
    return GL_TRUE;
 }
 
 
 struct xmesa_renderbuffer *
-xmesa_new_renderbuffer(GLcontext *ctx, GLuint name, GLboolean rgbMode)
+xmesa_new_renderbuffer(GLcontext *ctx, GLuint name, GLboolean rgbMode,
+                       GLboolean backBuffer)
 {
    struct xmesa_renderbuffer *xrb = CALLOC_STRUCT(xmesa_renderbuffer);
    if (xrb) {
@@ -93,7 +115,10 @@ xmesa_new_renderbuffer(GLcontext *ctx, GLuint name, GLboolean rgbMode)
       _mesa_init_renderbuffer(&xrb->Base, name);
 
       xrb->Base.Delete = xmesa_delete_renderbuffer;
-      xrb->Base.AllocStorage = xmesa_alloc_storage;
+      if (backBuffer)
+         xrb->Base.AllocStorage = xmesa_alloc_back_storage;
+      else
+         xrb->Base.AllocStorage = xmesa_alloc_front_storage;
 
       if (rgbMode) {
          xrb->Base.InternalFormat = GL_RGBA;
diff --git a/src/mesa/drivers/x11/xm_dd.c b/src/mesa/drivers/x11/xm_dd.c
index 76dec19f531..fcfe32ed42f 100644
--- a/src/mesa/drivers/x11/xm_dd.c
+++ b/src/mesa/drivers/x11/xm_dd.c
@@ -114,8 +114,8 @@ get_buffer_size( GLframebuffer *buffer, GLuint *width, GLuint *height )
 
    _glthread_LOCK_MUTEX(_xmesa_lock);
    XSync(xmBuffer->xm_visual->display, 0); /* added for Chromium */
-   XGetGeometry( xmBuffer->xm_visual->display, xmBuffer->frontxrb->pixmap, &root,
-		 &winx, &winy, &winwidth, &winheight, &bw, &d );
+   XGetGeometry( xmBuffer->xm_visual->display, xmBuffer->frontxrb->pixmap,
+                 &root, &winx, &winy, &winwidth, &winheight, &bw, &d );
    _glthread_UNLOCK_MUTEX(_xmesa_lock);
 #endif
 
@@ -1095,6 +1095,34 @@ choose_tex_format( GLcontext *ctx, GLint internalFormat,
 
 
 /**
+ * Get the current drawing (and reading) window's size and update the
+ * corresponding gl_framebuffer(s) if needed.
+ */
+static void
+update_framebuffer_size(GLcontext *ctx)
+{
+   struct gl_framebuffer *fb = ctx->WinSysDrawBuffer;
+   GLuint newWidth, newHeight;
+   get_buffer_size(fb, &newWidth, &newHeight);
+   if (newWidth != fb->Width || newHeight != fb->Height) {
+      xmesa_resize_buffers(ctx, fb, newWidth, newHeight);
+      ctx->NewState |= _NEW_BUFFERS;  /* to update scissor / window bounds */
+   }
+
+   if (ctx->WinSysReadBuffer != ctx->WinSysDrawBuffer) {
+      /* Update readbuffer's size */
+      struct gl_framebuffer *fb = ctx->WinSysReadBuffer;
+      GLuint newWidth, newHeight;
+      get_buffer_size(fb, &newWidth, &newHeight);
+      if (newWidth != fb->Width || newHeight != fb->Height) {
+         xmesa_resize_buffers(ctx, fb, newWidth, newHeight);
+         ctx->NewState |= _NEW_BUFFERS;
+      }
+   }
+}
+
+
+/**
  * Called by glViewport.
  * This is a good time for us to poll the current X window size and adjust
  * our renderbuffers to match the current window size.
@@ -1107,26 +1135,7 @@ choose_tex_format( GLcontext *ctx, GLint internalFormat,
 static void
 xmesa_viewport(GLcontext *ctx, GLint x, GLint y, GLsizei w, GLsizei h)
 {
-#if 1
-   struct gl_framebuffer *fb = ctx->WinSysDrawBuffer;
-   GLuint newWidth, newHeight;
-
-   /*
-   printf("%s before %d x %d\n", __FUNCTION__, fb->Width, fb->Height);
-   */
-
-   get_buffer_size(fb, &newWidth, &newHeight);
-   if (newWidth != fb->Width || newHeight != fb->Height) {
-      xmesa_resize_buffers(ctx, fb, newWidth, newHeight);
-      ctx->NewState |= _NEW_BUFFERS;  /* to update scissor / window bounds */
-   }
-   /*
-   printf("%s after %d x %d\n", __FUNCTION__, fb->Width, fb->Height);
-   */
-#else
-   /* This also works: */
-   _mesa_ResizeBuffersMESA();
-#endif
+   update_framebuffer_size(ctx);
 }
 
 
diff --git a/src/mesa/drivers/x11/xmesaP.h b/src/mesa/drivers/x11/xmesaP.h
index 7030afaa119..5f4e3d4cf29 100644
--- a/src/mesa/drivers/x11/xmesaP.h
+++ b/src/mesa/drivers/x11/xmesaP.h
@@ -156,6 +156,11 @@ typedef enum {
 } BufferType;
 
 
+/* Values for db_mode: */
+#define BACK_PIXMAP	1
+#define BACK_XIMAGE	2
+
+
 struct xmesa_renderbuffer
 {
    struct gl_renderbuffer Base;  /* Base class */
@@ -174,7 +179,7 @@ struct xmesa_renderbuffer
    GLuint *origin4;	/* used for PIXEL_ADDR4 macro */
    GLint width4;
 
-   GLint bottom;	/* used for FLIP macro */
+   GLint bottom;	/* used for FLIP macro, equals height - 1 */
 
    ClearFunc clearFunc;
 };
@@ -199,19 +204,17 @@ struct xmesa_buffer {
 
    unsigned long selectedEvents;/* for pbuffers only */
 
-   GLint db_state;		/* 0 = single buffered */
+   GLint db_mode;		/* 0 = single buffered */
 				/* BACK_PIXMAP = use Pixmap for back buffer */
 				/* BACK_XIMAGE = use XImage for back buffer */
 
-#ifndef XFree86Server
    GLuint shm;			/* X Shared Memory extension status:	*/
 				/*    0 = not available			*/
 				/*    1 = XImage support available	*/
 				/*    2 = Pixmap support available too	*/
-#ifdef USE_XSHM
+#if defined(USE_XSHM) && !defined(XFree86Server)
    XShmSegmentInfo shminfo;
 #endif
-#endif
 
    XMesaImage *rowimage;	/* Used for optimized span writing */
    XMesaPixmap stipple_pixmap;	/* For polygon stippling */
@@ -252,12 +255,6 @@ struct xmesa_buffer {
 };
 
 
-/* Values for xmesa->db_state: */
-#define FRONT_PIXMAP	1
-#define BACK_PIXMAP	2
-#define BACK_XIMAGE	4
-
-
 /*
  * If pixelformat==PF_TRUECOLOR:
  */
@@ -489,7 +486,8 @@ extern const int xmesa_kernel1[16];
  */
 
 extern struct xmesa_renderbuffer *
-xmesa_new_renderbuffer(GLcontext *ctx, GLuint name, GLboolean rgbMode);
+xmesa_new_renderbuffer(GLcontext *ctx, GLuint name, GLboolean rgbMode,
+                       GLboolean backBuffer);
 
 extern unsigned long
 xmesa_color_to_pixel( GLcontext *ctx,