New glXUseRotatedXFontMESA() function. Like glXUseXFont(), but takes

a rotation parameter (either 0, 90, 180 or 270 degrees).
Also, a demo program.

1 files changed, 399 insertions, 0 deletions

diff --git a/progs/xdemos/xuserotfont.c b/progs/xdemos/xuserotfont.c
new file mode 100644
index 00000000000..c7724818d57
--- /dev/null
+++ b/progs/xdemos/xuserotfont.c
@@ -0,0 +1,399 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  6.0
+ *
+ * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+/* \file xuserotfont.c
+ *
+ * A function like glXUseXFont() but takes a 0, 90, 180 or 270 degree
+ * rotation angle for rotated text display.
+ *
+ * Based on Mesa's glXUseXFont implementation written by Thorsten Ohl.
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <GL/glx.h>
+#include "xuserotfont.h"
+
+
+/**
+ * Generate OpenGL-compatible bitmap by drawing an X character glyph
+ * to an off-screen pixmap, then getting the image and testing pixels.
+ * \param width  bitmap width in pixels
+ * \param height  bitmap height in pixels
+ */
+static void
+fill_bitmap(Display *dpy, Pixmap pixmap, GC gc,
+	    unsigned int bitmapWidth, unsigned int bitmapHeight,
+            unsigned int charWidth, unsigned int charHeight,
+	    int xPos, int yPos, unsigned int c, GLubyte * bitmap,
+            int rotation)
+{
+   const int bytesPerRow = (bitmapWidth + 7) / 8;
+   XImage *image;
+   XChar2b char2b;
+
+   /* clear pixmap to 0 */
+   XSetForeground(dpy, gc, 0);
+   XFillRectangle(dpy, pixmap, gc, 0, 0, charWidth, charHeight);
+
+   /* The glyph is drawn snug up against the left/top edges of the pixmap */
+   XSetForeground(dpy, gc, 1);
+   char2b.byte1 = (c >> 8) & 0xff;
+   char2b.byte2 = (c & 0xff);
+   XDrawString16(dpy, pixmap, gc, xPos, yPos, &char2b, 1);
+
+   /* initialize GL bitmap */
+   memset(bitmap, 0, bytesPerRow * bitmapHeight);
+
+   image = XGetImage(dpy, pixmap, 0, 0, charWidth, charHeight, 1, XYPixmap);
+   if (image) {
+      /* Set appropriate bits in the GL bitmap.
+       * Note: X11 and OpenGL are upside down wrt each other).
+       */
+      unsigned int x, y;
+      if (rotation == 0) {
+         for (y = 0; y < charHeight; y++) {
+            for (x = 0; x < charWidth; x++) {
+               if (XGetPixel(image, x, y)) {
+                  int y2 = bitmapHeight - y - 1;
+                  bitmap[bytesPerRow * y2 + x / 8] |= (1 << (7 - (x % 8)));
+               }
+            }
+         }
+      }
+      else if (rotation == 90) {
+         for (y = 0; y < charHeight; y++) {
+            for (x = 0; x < charWidth; x++) {
+               if (XGetPixel(image, x, y)) {
+                  int x2 = y;
+                  int y2 = x;
+                  bitmap[bytesPerRow * y2 + x2 / 8] |= (1 << (7 - (x2 % 8)));
+               }
+            }
+         }
+      }
+      else if (rotation == 180) {
+         for (y = 0; y < charHeight; y++) {
+            for (x = 0; x < charWidth; x++) {
+               if (XGetPixel(image, x, y)) {
+                  int x2 = charWidth - x - 1;
+                  bitmap[bytesPerRow * y + x2 / 8] |= (1 << (7 - (x2 % 8)));
+               }
+            }
+         }
+      }
+      else {
+         assert(rotation == 270);
+         for (y = 0; y < charHeight; y++) {
+            for (x = 0; x < charWidth; x++) {
+               if (XGetPixel(image, x, y)) {
+                  int x2 = charHeight - y - 1;
+                  int y2 = charWidth - x - 1;
+                  bitmap[bytesPerRow * y2 + x2 / 8] |= (1 << (7 - (x2 % 8)));
+               }
+            }
+         }
+      }
+      XDestroyImage(image);
+   }
+}
+
+
+/*
+ * Determine if a given glyph is valid and return the
+ * corresponding XCharStruct.
+ */
+static const XCharStruct *
+isvalid(const XFontStruct * fs, unsigned int which)
+{
+   unsigned int rows, pages;
+   unsigned int byte1 = 0, byte2 = 0;
+   int i, valid = 1;
+
+   rows = fs->max_byte1 - fs->min_byte1 + 1;
+   pages = fs->max_char_or_byte2 - fs->min_char_or_byte2 + 1;
+
+   if (rows == 1) {
+      /* "linear" fonts */
+      if ((fs->min_char_or_byte2 > which) || (fs->max_char_or_byte2 < which))
+	 valid = 0;
+   }
+   else {
+      /* "matrix" fonts */
+      byte2 = which & 0xff;
+      byte1 = which >> 8;
+      if ((fs->min_char_or_byte2 > byte2) ||
+	  (fs->max_char_or_byte2 < byte2) ||
+	  (fs->min_byte1 > byte1) || (fs->max_byte1 < byte1))
+	 valid = 0;
+   }
+
+   if (valid) {
+      if (fs->per_char) {
+	 if (rows == 1) {
+	    /* "linear" fonts */
+	    return fs->per_char + (which - fs->min_char_or_byte2);
+	 }
+	 else {
+	    /* "matrix" fonts */
+	    i = ((byte1 - fs->min_byte1) * pages) +
+	       (byte2 - fs->min_char_or_byte2);
+	    return fs->per_char + i;
+	 }
+      }
+      else {
+	 return &fs->min_bounds;
+      }
+   }
+   return NULL;
+}
+
+
+void
+glXUseRotatedXFontMESA(Font font, int first, int count, int listbase,
+                       int rotation)
+{
+   Display *dpy;
+   Window win;
+   Pixmap pixmap;
+   GC gc;
+   XFontStruct *fs;
+   GLint swapbytes, lsbfirst, rowlength;
+   GLint skiprows, skippixels, alignment;
+   unsigned int maxCharWidth, maxCharHeight;
+   GLubyte *bm;
+   int i;
+
+   if (rotation != 0 &&
+       rotation != 90 &&
+       rotation != 180 &&
+       rotation != 270)
+      return;
+
+   dpy = glXGetCurrentDisplay();
+   if (!dpy)
+      return;			/* I guess glXMakeCurrent wasn't called */
+   win = RootWindow(dpy, DefaultScreen(dpy));
+
+   fs = XQueryFont(dpy, font);
+   if (!fs) {
+      /*
+      _mesa_error(NULL, GL_INVALID_VALUE,
+		  "Couldn't get font structure information");
+      */
+      return;
+   }
+
+   /* Allocate a GL bitmap that can fit any character */
+   maxCharWidth = fs->max_bounds.rbearing - fs->min_bounds.lbearing;
+   maxCharHeight = fs->max_bounds.ascent + fs->max_bounds.descent;
+   /* use max, in case we're rotating */
+   if (rotation == 90 || rotation == 270) {
+      /* swap width/height */
+      bm = (GLubyte *) malloc((maxCharHeight + 7) / 8 * maxCharWidth);
+   }
+   else {
+      /* normal or upside down */
+      bm = (GLubyte *) malloc((maxCharWidth + 7) / 8 * maxCharHeight);
+   }
+   if (!bm) {
+      XFreeFontInfo(NULL, fs, 1);
+      /*
+      _mesa_error(NULL, GL_OUT_OF_MEMORY,
+		  "Couldn't allocate bitmap in glXUseXFont()");
+      */
+      return;
+   }
+
+#if 0
+   /* get the page info */
+   pages = fs->max_char_or_byte2 - fs->min_char_or_byte2 + 1;
+   firstchar = (fs->min_byte1 << 8) + fs->min_char_or_byte2;
+   lastchar = (fs->max_byte1 << 8) + fs->max_char_or_byte2;
+   rows = fs->max_byte1 - fs->min_byte1 + 1;
+   unsigned int first_char, last_char, pages, rows;
+#endif
+
+   /* Save the current packing mode for bitmaps.  */
+   glGetIntegerv(GL_UNPACK_SWAP_BYTES, &swapbytes);
+   glGetIntegerv(GL_UNPACK_LSB_FIRST, &lsbfirst);
+   glGetIntegerv(GL_UNPACK_ROW_LENGTH, &rowlength);
+   glGetIntegerv(GL_UNPACK_SKIP_ROWS, &skiprows);
+   glGetIntegerv(GL_UNPACK_SKIP_PIXELS, &skippixels);
+   glGetIntegerv(GL_UNPACK_ALIGNMENT, &alignment);
+
+   /* Enforce a standard packing mode which is compatible with
+      fill_bitmap() from above.  This is actually the default mode,
+      except for the (non)alignment.  */
+   glPixelStorei(GL_UNPACK_SWAP_BYTES, GL_FALSE);
+   glPixelStorei(GL_UNPACK_LSB_FIRST, GL_FALSE);
+   glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
+   glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
+   glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
+   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+
+   /* Create pixmap and GC */
+   pixmap = XCreatePixmap(dpy, win, maxCharWidth, maxCharHeight, 1);
+   {
+      XGCValues values;
+      unsigned long valuemask;
+      values.foreground = BlackPixel(dpy, DefaultScreen(dpy));
+      values.background = WhitePixel(dpy, DefaultScreen(dpy));
+      values.font = fs->fid;
+      valuemask = GCForeground | GCBackground | GCFont;
+      gc = XCreateGC(dpy, pixmap, valuemask, &values);
+   }
+
+#ifdef DEBUG_XROT
+   if (debug_xfonts)
+      dump_font_struct(fs);
+#endif
+
+   for (i = 0; i < count; i++) {
+      const unsigned int c = first + i;
+      const int list = listbase + i;
+      unsigned int charWidth, charHeight;
+      unsigned int bitmapWidth, bitmapHeight;
+      GLfloat xOrig, yOrig, xStep, yStep, dtemp;
+      const XCharStruct *ch;
+      int xPos, yPos;
+      int valid;
+
+      /* check on index validity and get the bounds */
+      ch = isvalid(fs, c);
+      if (!ch) {
+	 ch = &fs->max_bounds;
+	 valid = 0;
+      }
+      else {
+	 valid = 1;
+      }
+
+#ifdef DEBUG_XROT
+      if (debug_xfonts) {
+	 char s[7];
+	 sprintf(s, isprint(c) ? "%c> " : "\\%03o> ", c);
+	 dump_char_struct(ch, s);
+      }
+#endif
+
+      /* glBitmap()' parameters:
+         straight from the glXUseXFont(3) manpage.  */
+      charWidth = ch->rbearing - ch->lbearing;
+      charHeight = ch->ascent + ch->descent;
+      xOrig = -ch->lbearing;
+      yOrig = ch->descent;
+      xStep = ch->width;
+      yStep = 0;
+
+      /* X11's starting point.  */
+      xPos = -ch->lbearing;
+      yPos = ch->ascent;
+
+      /* Apply rotation */
+      switch (rotation) {
+      case 0:
+         /* nothing */
+         bitmapWidth = charWidth;
+         bitmapHeight = charHeight;
+         break;
+      case 90:
+         /* xStep, yStep */
+         dtemp = xStep;
+         xStep = -yStep;
+         yStep = dtemp;
+         /* xOrig, yOrig */
+         yOrig = xOrig;
+         xOrig = charHeight - (charHeight - yPos);
+         /* width, height */
+         bitmapWidth = charHeight;
+         bitmapHeight = charWidth;
+         break;
+      case 180:
+         /* xStep, yStep */
+         xStep = -xStep;
+         yStep = -yStep;
+         /* xOrig, yOrig */
+         xOrig = charWidth - xOrig - 1;
+         yOrig = charHeight - yOrig - 1;
+         bitmapWidth = charWidth;
+         bitmapHeight = charHeight;
+         break;
+      case 270:
+         /* xStep, yStep */
+         dtemp = xStep;
+         xStep = yStep;
+         yStep = -dtemp;
+         /* xOrig, yOrig */
+         dtemp = yOrig;
+         yOrig = charWidth - xOrig;
+         xOrig = dtemp;
+         /* width, height */
+         bitmapWidth = charHeight;
+         bitmapHeight = charWidth;
+         break;
+      default:
+         /* should never get here */
+         ;
+      }
+
+      glNewList(list, GL_COMPILE);
+      if (valid && bitmapWidth > 0 && bitmapHeight > 0) {
+
+	 fill_bitmap(dpy, pixmap, gc, bitmapWidth, bitmapHeight,
+                     charWidth, charHeight,
+                     xPos, yPos, c, bm, rotation);
+
+	 glBitmap(bitmapWidth, bitmapHeight, xOrig, yOrig, xStep, yStep, bm);
+
+#ifdef DEBUG_XROT
+	 if (debug_xfonts) {
+	    printf("width/height = %u/%u\n", bitmapWidth, bitmapHeight);
+	    dump_bitmap(bitmapWidth, bitmapHeight, bm);
+	 }
+#endif
+      }
+      else {
+	 glBitmap(0, 0, 0.0, 0.0, xStep, yStep, NULL);
+      }
+      glEndList();
+   }
+
+   free(bm);
+   XFreeFontInfo(NULL, fs, 1);
+   XFreePixmap(dpy, pixmap);
+   XFreeGC(dpy, gc);
+
+   /* Restore saved packing modes.  */
+   glPixelStorei(GL_UNPACK_SWAP_BYTES, swapbytes);
+   glPixelStorei(GL_UNPACK_LSB_FIRST, lsbfirst);
+   glPixelStorei(GL_UNPACK_ROW_LENGTH, rowlength);
+   glPixelStorei(GL_UNPACK_SKIP_ROWS, skiprows);
+   glPixelStorei(GL_UNPACK_SKIP_PIXELS, skippixels);
+   glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);
+}
+
+