Fixed a problem in GL init code which prevented zinc from

working with Mesa.
A (hopefully) more useful warning is emitted when openGL
rendering is not good enough (most often 24 bits buffer
or stencil not available).
Tweaking and bending in the openGL init code to make it
work better.

1 files changed, 56 insertions, 29 deletions

diff --git a/generic/tkZinc.c b/generic/tkZinc.c
index dfa9614..0e4d878 100644
--- a/generic/tkZinc.c
+++ b/generic/tkZinc.c
@@ -139,10 +139,12 @@ static  int		ZnMajorGlx, ZnMinorGlx;
 static  int		ZnGLAttribs[] = {
   GLX_RGBA,
   GLX_DOUBLEBUFFER,
-  GLX_BUFFER_SIZE, 24,
-  /*GLX_BUFFER_SIZE, 32,*/
+  GLX_RED_SIZE, 8,
+  GLX_GREEN_SIZE, 8,
+  GLX_BLUE_SIZE, 8,
   GLX_STENCIL_SIZE, 8,
   /*GLX_ALPHA_SIZE, 8,*/
+  GLX_DEPTH_SIZE, 0,
   None
 };
 #endif
@@ -916,6 +918,7 @@ ZnGLMakeCurrent(Display	*dpy,
   ZnGLContextEntry *ce;
 
   ce = ZnGetGLContext(dpy);
+
   if (!wi) {
     /* Get a zinc widget from the context struct
      * for this display. If no more are left,
@@ -983,12 +986,10 @@ ZnGLSwapBuffers(ZnGLContextEntry *ce,
 
 #ifdef GL
 static void
-InitRendering(ZnWInfo	*wi)
+InitRendering1(ZnWInfo	*wi)
 {
   ZnGLContextEntry	*ce;
   ZnGLContext		gl_context;
-  GLfloat		r[2]; /* Min, Max */
-  GLint			i[1];
 
   if (wi->render) {
 #  ifdef _WIN32
@@ -1023,12 +1024,13 @@ InitRendering(ZnWInfo	*wi)
       ce->pfd.iLayerType = PFD_MAIN_PLANE;
       ce->ipixel = ChoosePixelFormat(ce->hdc, &ce->pfd);
       /*printf("ipixel=%d dwFlags=0x%x req=0x%x iPixelType=%d hdc=%d\n",
-	ce->ipixel,
-	ce->pfd.dwFlags,
+	ce->ipixel,	ce->pfd.dwFlags,
 	PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|PFD_DOUBLEBUFFER,	      
 	ce->pfd.iPixelType==PFD_TYPE_RGBA,
 	ce->hdc);*/
-      if (!ce->ipixel) {
+      if (!ce->ipixel ||
+	  (ce->pfd.cRedBits != 8) || (ce->pfd.cGreenBits != 8) || (ce->pfd.cBlueBits != 8) ||
+	  (ce->pfd.cStencilBits != 8)) {
 	fprintf(stderr, "ChoosePixelFormat failed\n");
       }
       
@@ -1135,7 +1137,17 @@ InitRendering(ZnWInfo	*wi)
       Tk_SetWindowVisual(wi->win, gl_visual->visual, 24, colormap);
     }
 #  endif /* _WIN32 */
+  }
+}
+
+static void
+InitRendering2(ZnWInfo	*wi)
+{
+  ZnGLContextEntry	*ce;
+  GLfloat		r[2]; /* Min, Max */
+  GLint			i[1];
 
+  if (wi->render) {
     ce = ZnGLMakeCurrent(wi->dpy, wi);
     glGetFloatv(ZN_GL_LINE_WIDTH_RANGE, r);
     ce->max_line_width = r[1];
@@ -1217,6 +1229,17 @@ ZincObjCmd(ClientData		client_data,	/* Main window associated with
       }
     }
   }
+  if (has_gl) {
+    XVisualInfo *visual = glXChooseVisual(dpy,
+					  XScreenNumberOfScreen(screen),
+					  ZnGLAttribs);
+    if (visual) {
+      XFree(visual);
+    }
+    else {
+      has_gl = False;
+    }
+  }
 #  endif
 #endif
 
@@ -1228,16 +1251,7 @@ ZincObjCmd(ClientData		client_data,	/* Main window associated with
     Tcl_AppendResult(interp, " GL", NULL);
 #  else
     if (has_gl) {
-      XVisualInfo *visual = glXChooseVisual(dpy,
-					    XScreenNumberOfScreen(screen),
-					    ZnGLAttribs);
-      if (visual) {
-	Tcl_AppendResult(interp, " GL", NULL);
-	XFree(visual);
-      }
-      else {
-	has_gl = False;
-      }
+      Tcl_AppendResult(interp, " GL", NULL);
     }
 #  endif
 #endif
@@ -1268,7 +1282,6 @@ ZincObjCmd(ClientData		client_data,	/* Main window associated with
   wi->real_top = None;
 
   ASSIGN(wi->flags, ZN_HAS_GL, has_gl);
-
 #if defined(SHAPE) && !defined(_WIN32)
   ASSIGN(wi->flags, ZN_HAS_X_SHAPE,
 	 XQueryExtension(wi->dpy, "SHAPE", &major_op, &first_evt, &first_err));
@@ -1429,14 +1442,6 @@ ZincObjCmd(ClientData		client_data,	/* Main window associated with
   wi->damaged_area.corner.x = wi->width = wi->opt_width;
   wi->damaged_area.corner.y = wi->height = wi->opt_height;
 
-  if (!has_gl) {
-    /* Do not allow GL rendering if not available. This should
-     * _not_ be changed later as images may have been created
-     * in the belief that GL will be available.
-     */
-    wi->render = 0;
-  }
-
   if (!wi->render) {
   /*
    * Allocate double buffer pixmap/image.
@@ -1444,6 +1449,9 @@ ZincObjCmd(ClientData		client_data,	/* Main window associated with
     wi->draw_buffer = Tk_GetPixmap(wi->dpy, RootWindowOfScreen(wi->screen),
 				   wi->width, wi->height, Tk_Depth(wi->win));
   }
+  else {
+    InitRendering1(wi);
+  }
 
 #ifdef PTK
   Tcl_SetObjResult(interp, LangWidgetObj(interp, tkwin));
@@ -6487,6 +6495,14 @@ Configure(Tcl_Interp		*interp,/* Used for error reporting. */
     }
     wi->render = render;
   }
+  /*
+   * Reset the render mode if GL is not available. It'll be too late
+   * to do this after images or fonts have been allocated.
+   */
+  if ((wi->render != 0) && ISCLEAR(wi->flags, ZN_HAS_GL)) {
+    fprintf(stderr, "GLX not available (need at least a 24 bits buffer with stencil)\n");
+    wi->render = 0;
+  }
 
 #ifdef GL
   if (CONFIG_PROBE(FONT_SPEC) || !wi->font_tfi) {
@@ -6729,6 +6745,14 @@ Configure(Tcl_Interp		*interp,/* Used for error reporting. */
     else if (wi->render < 0) {
       wi->render = 0;
     }
+    /*
+     * Reset the render mode if GL is not available. It'll be too late
+     * to do this after images or fonts have been allocated.
+     */
+    else if ((wi->render != 0) && ISCLEAR(wi->flags, ZN_HAS_GL)) {
+      fprintf(stderr, "GLX not available (need at least a 24 bits buffer with stencil)\n");
+      wi->render = 0;
+    }
 
     if ((mask & CONFIG_SCROLL_REGION) || init) {
       /*
@@ -7065,7 +7089,7 @@ Event(ClientData client_data,	/* Information about widget. */
     if (!wi->gc) {
       SET(wi->flags, ZN_REALIZED);
 #ifdef GL
-      InitRendering(wi);
+      InitRendering2(wi);
 #endif
 
       /*
@@ -8109,7 +8133,10 @@ Destroy(char *mem_ptr)		/* Info about the widget. */
       wglDeleteContext(ce->context);
 #else
       glXDestroyContext(ce->dpy, ce->context);
-      XFreeColormap(ce->dpy, ce->colormap);
+      /*
+       * This call seems to be a problem for X11/Mesa
+       */
+      /*XFreeColormap(ce->dpy, ce->colormap);*/
       XFree(ce->visual);
 #endif
       ZnListFree(ce->widgets);