CelestiaContent/src/texfont.cpp

528 lines
13 KiB
C++

/* Copyright (c) Mark J. Kilgard, 1997. */
/* This program is freely distributable without licensing fees and is
provided without guarantee or warrantee expressed or implied. This
program is -not- in the public domain. */
#if defined(_WIN32)
#pragma warning (disable:4244) /* disable bogus conversion warnings */
#endif
#include <assert.h>
#include <ctype.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#ifdef _WIN32
#include <windows.h>
#endif
#include <GL/glu.h>
#include "texfont.h"
using namespace std;
#if 0
/* Uncomment to debug various scenarios. */
#undef GL_VERSION_1_1
#undef GL_EXT_texture_object
#undef GL_EXT_texture
#endif
#ifndef GL_VERSION_1_1
# if defined(GL_EXT_texture_object)
# define glGenTextures glGenTexturesEXT
# define glBindTexture glBindTextureEXT
# else
/* Without OpenGL 1.1 or the texture object extension, use display lists. */
# define USE_DISPLAY_LISTS
# endif
# if defined(GL_EXT_texture)
# define GL_INTENSITY4 GL_INTENSITY4_EXT
int useLuminanceAlpha = 0;
# else
/* Intensity texture format not in OpenGL 1.0; added by the EXT_texture
extension and now part of OpenGL 1.1. */
int useLuminanceAlpha = 1;
# endif
#else
/* OpenGL 1.1 case. */
int useLuminanceAlpha = 0;
#endif
static TexGlyphVertexInfo NullGlyph = {
{ 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 },
{ 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 },
0
};
/* byte swap a 32-bit value */
#define SWAPL(x, n) { \
n = ((char *) (x))[0];\
((char *) (x))[0] = ((char *) (x))[3];\
((char *) (x))[3] = n;\
n = ((char *) (x))[1];\
((char *) (x))[1] = ((char *) (x))[2];\
((char *) (x))[2] = n; }
/* byte swap a short */
#define SWAPS(x, n) { \
n = ((char *) (x))[0];\
((char *) (x))[0] = ((char *) (x))[1];\
((char *) (x))[1] = n; }
static TexGlyphVertexInfo *getTCVI(TexFont * txf, int c)
{
TexGlyphVertexInfo *tgvi;
/* Automatically substitute uppercase letters with lowercase if not
uppercase available (and vice versa). */
if ((c >= txf->min_glyph) && (c < txf->min_glyph + txf->range)) {
tgvi = txf->lut[c - txf->min_glyph];
if (tgvi) {
return tgvi;
}
if (islower(c)) {
c = toupper(c);
if ((c >= txf->min_glyph) && (c < txf->min_glyph + txf->range)) {
return txf->lut[c - txf->min_glyph];
}
}
if (isupper(c)) {
c = tolower(c);
if ((c >= txf->min_glyph) && (c < txf->min_glyph + txf->range)) {
return txf->lut[c - txf->min_glyph];
}
}
}
return &NullGlyph;
#if 0
fprintf(stderr,
"texfont: tried to access unavailable font character \"%c\" (%d)\n",
isprint(c) ? c : ' ', c);
abort();
/* NOTREACHED */
#endif
}
static char *lastError;
char *txfErrorString(void)
{
return lastError;
}
TexFont *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;
unsigned long 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;
}
/*CONSTANTCONDITION*/ 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 != (unsigned long) 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;
}
/*CONSTANTCONDITION*/ 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;
txf->max_width = -1; // Celestia addition
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;
if (tgi->width > txf->max_width)
txf->max_width = tgi->width; // Celestia addition
}
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
txfEstablishTexture(TexFont * txf, 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);
#else
glNewList(txf->texobj, GL_COMPILE);
#endif
if (useLuminanceAlpha) {
if (setupMipmaps) {
gluBuild2DMipmaps(GL_TEXTURE_2D, GL_LUMINANCE_ALPHA,
txf->tex_width, txf->tex_height,
GL_LUMINANCE_ALPHA, GL_UNSIGNED_BYTE,
txf->teximage);
} else {
glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE_ALPHA,
txf->tex_width, txf->tex_height, 0,
GL_LUMINANCE_ALPHA, GL_UNSIGNED_BYTE,
txf->teximage);
}
} else {
#if defined(GL_VERSION_1_1) || defined(GL_EXT_texture)
/* Use GL_INTENSITY4 as internal texture format since we want to use as
little texture memory as possible. */
if (setupMipmaps) {
gluBuild2DMipmaps(GL_TEXTURE_2D, GL_INTENSITY4,
txf->tex_width, txf->tex_height,
GL_LUMINANCE, GL_UNSIGNED_BYTE,
txf->teximage);
} else {
glTexImage2D(GL_TEXTURE_2D, 0, GL_INTENSITY4,
txf->tex_width, txf->tex_height, 0,
GL_LUMINANCE, GL_UNSIGNED_BYTE, txf->teximage);
}
#else
abort(); /* Should not get here without EXT_texture or OpenGL
1.1. */
#endif
}
#if defined(USE_DISPLAY_LISTS)
glEndList();
glCallList(txf->texobj);
#endif
return txf->texobj;
}
void txfBindFontTexture(TexFont * txf)
{
#if !defined(USE_DISPLAY_LISTS)
glBindTexture(GL_TEXTURE_2D, txf->texobj);
#else
glCallList(txf->texobj);
#endif
}
void txfUnloadFont(TexFont * txf)
{
if (txf->teximage) {
free(txf->teximage);
}
free(txf->tgi);
free(txf->tgvi);
free(txf->lut);
free(txf);
}
void
txfGetStringMetrics(TexFont* txf,
char* s, int len,
int& width, int& maxAscent, int& maxDescent)
{
TexGlyphVertexInfo *tgvi;
int w = 0;
for (int i = 0; i < len; i++)
{
tgvi = getTCVI(txf, s[i]);
w += (int) tgvi->advance;
}
width = w;
maxAscent = txf->max_ascent;
maxDescent = txf->max_descent;
}
void
txfGetStringMetrics(TexFont* txf,
string s,
int& width, int& maxAscent, int& maxDescent)
{
TexGlyphVertexInfo *tgvi;
int w = 0;
for (int i = 0; i < s.length(); i++)
{
tgvi = getTCVI(txf, s[i]);
w += (int) tgvi->advance;
}
width = w;
maxAscent = txf->max_ascent;
maxDescent = txf->max_descent;
}
void txfRenderGlyph(TexFont * txf, int c)
{
TexGlyphVertexInfo *tgvi;
float dx = 0.5f / (float) txf->tex_width;
float dy = 0.5f / (float) txf->tex_height;
tgvi = getTCVI(txf, c);
glBegin(GL_QUADS);
glTexCoord2fv(tgvi->t0);
// glVertex2sv(tgvi->v0);
glVertex2f(tgvi->v0[0], tgvi->v0[1] - 0.1f);
glTexCoord2fv(tgvi->t1);
// glVertex2sv(tgvi->v1);
glVertex2f(tgvi->v1[0], tgvi->v1[1] - 0.1f);
glTexCoord2fv(tgvi->t2);
glVertex2sv(tgvi->v2);
glTexCoord2fv(tgvi->t3);
glVertex2sv(tgvi->v3);
glEnd();
glTranslatef(tgvi->advance, 0.0, 0.0);
}
void txfRenderString(TexFont * txf, char *s, int len)
{
for (int i = 0; i < len; i++)
txfRenderGlyph(txf, s[i]);
}
void txfRenderString(TexFont * txf, string s)
{
for (int i = 0; i < s.length(); i++)
txfRenderGlyph(txf, s[i]);
}
int txfInFont(TexFont * txf, int c)
{
/* NOTE: No uppercase/lowercase substituion. */
if ((c >= txf->min_glyph) && (c < txf->min_glyph + txf->range)) {
if (txf->lut[c - txf->min_glyph]) {
return 1;
}
}
return 0;
}