xenocara/dist/Mesa/progs/xdemos/xuserotfont.c
2006-11-25 18:56:37 +00:00

400 lines
12 KiB
C

/*
* Mesa 3-D graphics library
* Version: 6.1
*
* 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 = 0, bitmapHeight = 0;
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);
}