New glXUseRotatedXFontMESA() function. Like glXUseXFont(), but takes
a rotation parameter (either 0, 90, 180 or 270 degrees).
Also, a demo program.
diff --git a/progs/xdemos/xuserotfont.c b/progs/xdemos/xuserotfont.c
new file mode 100644
index 0000000..c772481
--- /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);
+}
+
+