text.cpp

S.C.O.U.R.G.E.是一款类似Rogue的游戏

/**
 * This code was originally written by Mark Kilgard ([e-mail]) (c) 1997
 * see: http://www.opengl.org/developers/code/mjktips/TexFont/TexFont.html
 */

/***************************************************************************
                          text.cpp  -  description
                             -------------------
    begin                : Mon Jul 7 2003
    copyright            : (C) 2003 by Gabor Torok
    email                : [e-mail]
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#include <assert.h>
#include <ctype.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "text.h"


TexturedText::TexturedText() {
    useLuminanceAlpha = 0;
    strcpy(filename, rootDir);
	strcat(filename, "/fonts/default.txf");
    txf = txfLoadFont(filename);
    if(txf == NULL) {
        fprintf(stderr, "Problem loading %s\n", filename);
        exit(1);
    }    
}

TexturedText::~TexturedText() {
}






TexFont *TexturedText::txfLoadFont(char *filename) {
  TexFont *txf;
  FILE *file;
  GLfloat w, h, xstep, ystep;
  char fileid[4], tmp;
  unsigned char *texbitmap;
  int min_glyph, max_glyph;
  int endianness, swap, format, stride, width, height;
  int i, j, got;

  txf = NULL;
  file = fopen(filename, "rb");
  if (file == NULL) {
    lastError = "file open failed.";
    goto error;
  }
  txf = (TexFont *) malloc(sizeof(TexFont));
  if (txf == NULL) {
    lastError = "out of memory.";
    goto error;
  }
  /* For easy cleanup in error case. */
  txf->tgi = NULL;
  txf->tgvi = NULL;
  txf->lut = NULL;
  txf->teximage = NULL;

  got = fread(fileid, 1, 4, file);
  if (got != 4 || strncmp(fileid, "\377txf", 4)) {
    lastError = "not a texture font file.";
    goto error;
  }
  assert(sizeof(int) == 4);  /* Ensure external file format size. */
  got = fread(&endianness, sizeof(int), 1, file);
  if (got == 1 && endianness == 0x12345678) {
    swap = 0;
  } else if (got == 1 && endianness == 0x78563412) {
    swap = 1;
  } else {
    lastError = "not a texture font file.";
    goto error;
  }
#define EXPECT(n) if (got != n) { lastError = "premature end of file."; goto error; }
  got = fread(&format, sizeof(int), 1, file);
  EXPECT(1);
  got = fread(&txf->tex_width, sizeof(int), 1, file);
  EXPECT(1);
  got = fread(&txf->tex_height, sizeof(int), 1, file);
  EXPECT(1);
  got = fread(&txf->max_ascent, sizeof(int), 1, file);
  EXPECT(1);
  got = fread(&txf->max_descent, sizeof(int), 1, file);
  EXPECT(1);
  got = fread(&txf->num_glyphs, sizeof(int), 1, file);
  EXPECT(1);

  if (swap) {
    SWAPL(&format, tmp);
    SWAPL(&txf->tex_width, tmp);
    SWAPL(&txf->tex_height, tmp);
    SWAPL(&txf->max_ascent, tmp);
    SWAPL(&txf->max_descent, tmp);
    SWAPL(&txf->num_glyphs, tmp);
  }
  txf->tgi = (TexGlyphInfo *) malloc(txf->num_glyphs * sizeof(TexGlyphInfo));
  if (txf->tgi == NULL) {
    lastError = "out of memory.";
    goto error;
  }
  assert(sizeof(TexGlyphInfo) == 12);  /* Ensure external file format size. */
  got = fread(txf->tgi, sizeof(TexGlyphInfo), txf->num_glyphs, file);
  EXPECT(txf->num_glyphs);

  if (swap) {
    for (i = 0; i < txf->num_glyphs; i++) {
      SWAPS(&txf->tgi[i].c, tmp);
      SWAPS(&txf->tgi[i].x, tmp);
      SWAPS(&txf->tgi[i].y, tmp);
    }
  }
  txf->tgvi = (TexGlyphVertexInfo *)
    malloc(txf->num_glyphs * sizeof(TexGlyphVertexInfo));
  if (txf->tgvi == NULL) {
    lastError = "out of memory.";
    goto error;
  }
  w = txf->tex_width;
  h = txf->tex_height;
  xstep = 0.5 / w;
  ystep = 0.5 / h;
  for (i = 0; i < txf->num_glyphs; i++) {
    TexGlyphInfo *tgi;

    tgi = &txf->tgi[i];
    txf->tgvi[i].t0[0] = tgi->x / w + xstep;
    txf->tgvi[i].t0[1] = tgi->y / h + ystep;
    txf->tgvi[i].v0[0] = tgi->xoffset;
    txf->tgvi[i].v0[1] = tgi->yoffset;
    txf->tgvi[i].t1[0] = (tgi->x + tgi->width) / w + xstep;
    txf->tgvi[i].t1[1] = tgi->y / h + ystep;
    txf->tgvi[i].v1[0] = tgi->xoffset + tgi->width;
    txf->tgvi[i].v1[1] = tgi->yoffset;
    txf->tgvi[i].t2[0] = (tgi->x + tgi->width) / w + xstep;
    txf->tgvi[i].t2[1] = (tgi->y + tgi->height) / h + ystep;
    txf->tgvi[i].v2[0] = tgi->xoffset + tgi->width;
    txf->tgvi[i].v2[1] = tgi->yoffset + tgi->height;
    txf->tgvi[i].t3[0] = tgi->x / w + xstep;
    txf->tgvi[i].t3[1] = (tgi->y + tgi->height) / h + ystep;
    txf->tgvi[i].v3[0] = tgi->xoffset;
    txf->tgvi[i].v3[1] = tgi->yoffset + tgi->height;
    txf->tgvi[i].advance = tgi->advance;
  }

  min_glyph = txf->tgi[0].c;
  max_glyph = txf->tgi[0].c;
  for (i = 1; i < txf->num_glyphs; i++) {
    if (txf->tgi[i].c < min_glyph) {
      min_glyph = txf->tgi[i].c;
    }
    if (txf->tgi[i].c > max_glyph) {
      max_glyph = txf->tgi[i].c;
    }
  }
  txf->min_glyph = min_glyph;
  txf->range = max_glyph - min_glyph + 1;

  txf->lut = (TexGlyphVertexInfo **)
    calloc(txf->range, sizeof(TexGlyphVertexInfo *));
  if (txf->lut == NULL) {
    lastError = "out of memory.";
    goto error;
  }
  for (i = 0; i < txf->num_glyphs; i++) {
    txf->lut[txf->tgi[i].c - txf->min_glyph] = &txf->tgvi[i];
  }

  switch (format) {
  case TXF_FORMAT_BYTE:
    if (useLuminanceAlpha) {
      unsigned char *orig;

      orig = (unsigned char *) malloc(txf->tex_width * txf->tex_height);
      if (orig == NULL) {
        lastError = "out of memory.";
        goto error;
      }
      got = fread(orig, 1, txf->tex_width * txf->tex_height, file);
      EXPECT(txf->tex_width * txf->tex_height);
      txf->teximage = (unsigned char *)
        malloc(2 * txf->tex_width * txf->tex_height);
      if (txf->teximage == NULL) {
        lastError = "out of memory.";
        goto error;
      }
      for (i = 0; i < txf->tex_width * txf->tex_height; i++) {
        txf->teximage[i * 2] = orig[i];
        txf->teximage[i * 2 + 1] = orig[i];
      }
      free(orig);
    } else {
      txf->teximage = (unsigned char *)
        malloc(txf->tex_width * txf->tex_height);
      if (txf->teximage == NULL) {
        lastError = "out of memory.";
        goto error;
      }
      got = fread(txf->teximage, 1, txf->tex_width * txf->tex_height, file);
      EXPECT(txf->tex_width * txf->tex_height);
    }
    break;
  case TXF_FORMAT_BITMAP:
    width = txf->tex_width;
    height = txf->tex_height;
    stride = (width + 7) >> 3;
    texbitmap = (unsigned char *) malloc(stride * height);
    if (texbitmap == NULL) {
      lastError = "out of memory.";
      goto error;
    }
    got = fread(texbitmap, 1, stride * height, file);
    EXPECT(stride * height);
    if (useLuminanceAlpha) {
      txf->teximage = (unsigned char *) calloc(width * height * 2, 1);
      if (txf->teximage == NULL) {
        lastError = "out of memory.";
        goto error;
      }
      for (i = 0; i < height; i++) {
        for (j = 0; j < width; j++) {
          if (texbitmap[i * stride + (j >> 3)] & (1 << (j & 7))) {
            txf->teximage[(i * width + j) * 2] = 255;
            txf->teximage[(i * width + j) * 2 + 1] = 255;
          }
        }
      }
    } else {
      txf->teximage = (unsigned char *) calloc(width * height, 1);
      if (txf->teximage == NULL) {
        lastError = "out of memory.";
        goto error;
      }
      for (i = 0; i < height; i++) {
        for (j = 0; j < width; j++) {
          if (texbitmap[i * stride + (j >> 3)] & (1 << (j & 7))) {
            txf->teximage[i * width + j] = 255;
          }
        }
      }
    }
    free(texbitmap);
    break;
  }

  fclose(file);
  return txf;

error:

  if (txf) {
    if (txf->tgi)
      free(txf->tgi);
    if (txf->tgvi)
      free(txf->tgvi);
    if (txf->lut)
      free(txf->lut);
    if (txf->teximage)
      free(txf->teximage);
    free(txf);
  }
  if (file)
    fclose(file);
  return NULL;
}

GLuint TexturedText::txfEstablishTexture(GLuint texobj,
                                         GLboolean setupMipmaps) {
  if (txf->texobj == 0) {
    if (texobj == 0) {
#if !defined(USE_DISPLAY_LISTS)
      glGenTextures(1, &txf->texobj);
#else
      txf->texobj = glGenLists(1);
#endif
    } else {
      txf->texobj = texobj;
    }
  }
#if !defined(USE_DISPLAY_LISTS)
  glBindTexture(GL_TEXTURE_2D, txf->texobj);