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Lephisto/src/font.c
Allanis 8fa9b389b1 [Add] Documentation for fonts.
2013-10-19 23:14:06 +01:00

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/**
* @file font.c
*
* @brief OpenGL font rendering routines.
*
* Use a displaylist to store ASCII chars rendered with freefont.
* There are several drawing methods depending on whether you want
* to print it all, print to a max width, print centered or print a
* block of text.
*
* There are hardcoded size limits. 256 characters for all routines
* except gl_printText which has a 1024 limit.
*
* @todo Check if length is too long.
*/
#include "font.h"
#include "ft2build.h"
#include "freetype/freetype.h"
#include "freetype/ftglyph.h"
#include "lephisto.h"
#include "log.h"
#include "pack.h"
#define FONT_DEF "../dat/font.ttf" /**< Default font path. */
/* Default font. */
glFont gl_defFont; /**< Default font. */
glFont gl_smallFont; /**< Small font. */
static void glFontMakeDList(FT_Face face, char ch,
GLuint list_base, GLuint* tex_base,
int* width_base);
/**
* @fn void gl_print(const glFont* ft_font, const double x, const double y,
* const glColour* c, const char* fmt, ...)
*
* @brief Print text on screen like printf.
*
* Defaults ft_font to gl_defFont if NULL.
* @param ft_font Font to use (NULL means gl_defFont).
* @param x X position to put text at.
* @param y Y position to put text at.
* @param c Colour to use (uses white if NULL).
* @param fmt String formatted like printf to print. *
*/
void gl_print(const glFont* ft_font, const double x, const double y,
const glColour* c, const char* fmt, ...) {
/*float h = ft_font->h / .63; // Slightly increases font size. */
char txt[256];
va_list ap;
if(ft_font == NULL) ft_font = &gl_defFont;
if(fmt == NULL) return;
else {
/* convert the symbols to text. */
va_start(ap, fmt);
vsprintf(txt, fmt, ap);
va_end(ap);
}
glEnable(GL_TEXTURE_2D);
glListBase(ft_font->list_base);
glMatrixMode(GL_MODELVIEW);
glPushMatrix(); /* Translation matrix. */
glTranslated(x - (double)SCREEN_W/2., y - (double)SCREEN_H/2., 0);
if(c == NULL) glColor4d(1., 1., 1., 1.);
else COLOUR(*c);
glCallLists(strlen(txt), GL_UNSIGNED_BYTE, &txt);
glPopMatrix(); /* Translation matrix. */
glDisable(GL_TEXTURE_2D);
gl_checkErr();
}
/**
* @fn int gl_printMax(const glFont* ft_font, const int max,
* const double x, const double y, const glColour* c, const char* fmt, ...)
*
* @brief Act like gl_print but stops displaying text after reaching a certain length.
* @param ft_font Font to use (Null means use gl_defFont).
* @param max Maximum length to reach.
* @param x X position to display text at.
* @param y Y position to display text at.
* @param c Colour to use (NULL defaults to white).
* @param fmt String to display formatted like printf.
* @return The number of characters it had to suppress.
*/
int gl_printMax(const glFont* ft_font, const int max,
const double x, const double y, const glColour* c, const char* fmt, ...) {
/*float h = ft_font->h / .63; // Slightly increases font size. */
char txt[256];
va_list ap;
int i, n, len, ret;
if(ft_font == NULL) ft_font = &gl_defFont;
if(fmt == NULL) return -1;
else {
/* convert the symbols to text. */
va_start(ap, fmt);
vsprintf(txt, fmt, ap);
va_end(ap);
}
/* Limit the size. */
len = (int)strlen(txt);
for(n = 0, i = 0; i < len; i++) {
n += ft_font->w[(int)txt[i]];
if(n > max) {
ret = len - i; /* Difference. */
txt[i] = '\0';
break;
}
}
/* Display the text. */
glEnable(GL_TEXTURE_2D);
glListBase(ft_font->list_base);
glMatrixMode(GL_MODELVIEW); /* Projection gets full fast using modelview. */
glPushMatrix(); /* Translation matrix. */
glTranslated(x - (double)SCREEN_W/2., y - (double)SCREEN_H/2., 0);
if(c == NULL) glColor4d(1., 1., 1., 1.);
else COLOUR(*c);
glCallLists(i, GL_UNSIGNED_BYTE, &txt);
glPopMatrix(); /* Translation matrix. */
glDisable(GL_TEXTURE_2D);
gl_checkErr();
return ret;
}
/**
* @fn int gl_printMid(const glFont* ft_font, const int width, double x, const double y,
* const glColour* c, const char* fmt, ...)
*
* @brief Display text centered in position and width.
*
* Will truncate if text is too long.
* @param ft_font Font to use (NULL defaults to gl_defFont).
* @param width Width of area to center in.
* @param x X Position to display text at.
* @param y Y Position to display text at.
* @param c Colour to use for text (NULL defaults to white).
* @param fmt Text to display formatted string like printf.
* @return The number of characters it had to truncate.
*/
int gl_printMid(const glFont* ft_font, const int width, double x, const double y,
const glColour* c, const char* fmt, ...) {
/*float h = ft_font->h / .63; // Slightly increases font size. */
char txt[256];
va_list ap;
int i, n, len, ret;
ret = 0; /* Default return value. */
if(ft_font == NULL) ft_font = &gl_defFont;
if(fmt == NULL) return -1;
else {
/* convert the symbols to text. */
va_start(ap, fmt);
vsprintf(txt, fmt, ap);
va_end(ap);
}
/* Limit the size. */
len = (int)strlen(txt);
for(n = 0, i = 0; i < len; i++) {
n += ft_font->w[(int)txt[i]];
if(n > width) {
ret = len - i; /* Difference. */
n -= ft_font->w[(int)txt[i]]; /* Actual size. */
txt[i] = '\0';
break;
}
}
x += (double)(width-n)/2.;
/* Display the text. */
glEnable(GL_TEXTURE_2D);
glListBase(ft_font->list_base);
glMatrixMode(GL_MODELVIEW); /* Projection gets full fast using modelview. */
glPushMatrix(); /* Translation matrix. */
glTranslated(x - (double)SCREEN_W/2., y - (double)SCREEN_H/2., 0);
if(c == NULL) glColor4d(1., 1., 1., 1.);
else COLOUR(*c);
glCallLists(i, GL_UNSIGNED_BYTE, &txt);
glPopMatrix(); /* Translation matrix. */
glDisable(GL_TEXTURE_2D);
gl_checkErr();
return ret;
}
/**
* @fn int gl_printText(const glFont* ft_font, const int width, const int height,
* double bx, double by, glColour* c, const char* fmt, ...)
*
* @brief Print a block of text that fits in the dimensions given.
*
* Positions are based on origin being top-left.
* @param ft_font Font to use (NULL defaults to gl_defFont).
* @param width Maximum width to print to.
* @param height Maximum height to print to.
* @param bx X position to display text at.
* @param by Y position to display text at.
* @param c Colour to use (NULL defaults to white).
* @param fmt Text to display formatted like printf.
* @return 0 on success.
*/
int gl_printText(const glFont* ft_font, const int width, const int height,
double bx, double by, glColour* c, const char* fmt, ...) {
/*float h = ft_font->h / .63; // Slightly increase font size. */
char txt[4096];
char buf[256];
va_list ap;
int p, i, j, n, m, len, ret, lastspace;
double x, y;
ret = 0; /* Default return value. */
if(ft_font == NULL) ft_font = &gl_defFont;
if(fmt == NULL) return -1;
else {
/* Convert the symbols to text. */
va_start(ap, fmt);
vsprintf(txt, fmt, ap);
va_end(ap);
}
bx -= (double)SCREEN_W/2.;
by -= (double)SCREEN_H/2.;
x = bx;
y = by + height - (double)ft_font->h; /* y is top left corner. */
/* Prepare opengl. */
glEnable(GL_TEXTURE_2D);
glListBase(ft_font->list_base);
if(c == NULL) glColor4d(1., 1., 1., 1.);
else COLOUR(*c);
len = (int)strlen(txt);
/* Limit size per line. */
lastspace = -1; /* Last ' ' or \n int text. */
n = 0; /* Current width. */
i = 0; /* Current position. */
p = -1; /* Where we last drew up to. */
while(i < len+1) {
if(by - y > (double)height) return len-lastspace; /* Past height. */
n += ft_font->w[(int)txt[i]];
if((txt[i] == ' ') || (txt[i] == '\n') || (txt[i] == '\0')) lastspace = i;
if(((n > width) && ((p != lastspace)))
|| (txt[i] == '\n') || (txt[i] == '\0')) {
/* Time to draw the line. */
m = 0;
if(lastspace == -1) lastspace = 0;
for(j = 0; j < (lastspace-p-1); j++) {
if(txt[p+j+1]=='\t') {
p++;
continue;
}
m += ft_font->w[(int)txt[p+j+1]];
if(m > width) break;
buf[j] = txt[p+j+1];
}
/* No need for null termination. */
glMatrixMode(GL_MODELVIEW); /* using modelview, projection gets full fast. */
glPushMatrix(); /* Translation matrix. */
glTranslated(x, y, 0);
/* This is what we are displaying. */
glCallLists(j, GL_UNSIGNED_BYTE, &buf);
glPopMatrix(); /* Translation matrix. */
p = lastspace;
n = 0;
i = lastspace;
y -= 1.5*(double)ft_font->h; /* Move position down. */
}
i++;
}
glDisable(GL_TEXTURE_2D);
gl_checkErr();
return ret;
}
/**
* @fn int gl_printWidth(const glFont* ft_font, const char* fmt, ...)
*
* @brief Get the width that it would take to print some text.
*
* Does not display text on screen.
* @param ft_font Font to use (NULL defaults to gl_defFont).
* @param fmt Text to calculate the length of.
* @return The length of the text in pixels.
*/
int gl_printWidth(const glFont* ft_font, const char* fmt, ...) {
int i, n;
char txt[256]; /* Holds the string. */
va_list ap;
if(ft_font == NULL) ft_font = &gl_defFont;
if(fmt == NULL) return 0;
else {
/* Convert the symbols to text. */
va_start(ap, fmt);
vsprintf(txt, fmt, ap);
va_end(ap);
}
for(n = 0, i = 0; i < (int)strlen(txt); i++)
n += ft_font->w[(int)txt[i]];
return n;
}
/**
* @fn int gl_printHeight(const glFont* ft_font, const int width,
* const char* fmt, ...)
*
* @brief Get the height of the text if it were printed.
*
* Does not display the text on screen.
* @param ft_font Font to use (NULL defaults to gl_defFont).
* @param width Width to jump to next line once reached.
* @param fmt Text to get the height of in printf format.
* @return The heiht of the text.
*/
int gl_printHeight(const glFont* ft_font, const int width,
const char* fmt, ...) {
char txt[1024]; /* Holds the string. */
va_list ap;
int p, i, n, len, lastspace;
double y;
if(ft_font == NULL) ft_font = &gl_defFont;
if(fmt == NULL) return -1;
else {
/* Convert the symbols to text. */
va_start(ap, fmt);
vsprintf(txt, fmt, ap);
va_end(ap);
}
y = 0.;
len = (int) strlen(txt);
/* Limit the size per line. */
lastspace = -1; /* Last ' ' or '\n' in the text. */
n = 0; /* Current width. */
i = 0; /* Current position. */
p = -1; /* Where we last drew up to. */
while(i < len+1) {
n += ft_font->w[(int)txt[i]];
if((txt[i] == ' ') || (txt[i] == '\n') || (txt[i] == '\0')) lastspace = i;
if(((n > width) && (p != lastspace)) ||
(txt[i] == '\n') || (txt[i] == '\0')) {
p = lastspace;
n = 0;
i = lastspace;
y += 1.5*(double)ft_font->h; /* Move position down. */
}
i++;
}
return (int)(y - 0.5*(double)ft_font->h);
}
/* ================
* FONT!
* ================
*/
/**
* @fn static void glFontMakeDList(FT_Face face, char ch, GLuint list_base,
* GLuint* tex_base, int* width_base)
*
* @brief Makes the font display list.
*/
static void glFontMakeDList(FT_Face face, char ch, GLuint list_base,
GLuint* tex_base, int* width_base) {
FT_Glyph glyph;
FT_Bitmap bitmap;
GLubyte* expanded_data;
int w, h;
int i, j;
double x, y;
if(FT_Load_Glyph(face, FT_Get_Char_Index(face, ch),
FT_LOAD_FORCE_AUTOHINT))
WARN("FT_Load_Glyph failed");
if(FT_Get_Glyph(face->glyph, &glyph))
WARN("FT_Ge_Glyph failed");
/* Convert your glyph to a bitmap. */
FT_Glyph_To_Bitmap(&glyph, FT_RENDER_MODE_NORMAL, 0, 1);
FT_BitmapGlyph bitmap_glyph = (FT_BitmapGlyph)glyph;
bitmap = bitmap_glyph->bitmap; /* To simplify. */
/* Need the POT wrapping for GL. */
w = gl_pot(bitmap.width);
h = gl_pot(bitmap.rows);
/* Memory for textured data. */
/* Bitmap is useing two channels, one for luminosity and one for alpha. */
expanded_data = (GLubyte*)malloc(sizeof(GLubyte)*2*w*h + 1);
for(j = 0; j < h; j++) {
for(i = 0; i < w; i++) {
expanded_data[2*(i+j*w)] = expanded_data[2*(i+j*w)+1] =
(i >= bitmap.width || j >= bitmap.rows) ?
0 : bitmap.buffer[i + bitmap.width*j];
}
}
/* Create the GL texture. */
glBindTexture(GL_TEXTURE_2D, tex_base[(int)ch]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_LUMINANCE_ALPHA,
GL_UNSIGNED_BYTE, expanded_data);
free(expanded_data); /* No need for this now. */
/* Create the display lists. */
glNewList(list_base+ch, GL_COMPILE);
/* Corrects a spacing flaw between letters and */
/* downwards correction for letters like g or y. */
glPushMatrix();
glTranslated(bitmap_glyph->left, bitmap_glyph->top-bitmap.rows, 0);
/* Take the opengl POT wrapping into account. */
x = (double)bitmap.width/(double)w;
y = (double)bitmap.rows/(double)h;
/* Draw the texture mapped quad. */
glBindTexture(GL_TEXTURE_2D, tex_base[(int)ch]);
glBegin(GL_QUADS);
glTexCoord2d(0, 0);
glVertex2d(0, bitmap.rows);
glTexCoord2d(x, 0);
glVertex2d(bitmap.width, bitmap.rows);
glTexCoord2d(x, y);
glVertex2d(bitmap.width, 0);
glTexCoord2d(0, y);
glVertex2d(0, 0);
glEnd();
glPopMatrix();
glTranslated(face->glyph->advance.x >> 6, 0,0);
width_base[(int)ch] = (int)(face->glyph->advance.x >> 6);
/* End of the display list. */
glEndList();
FT_Done_Glyph(glyph);
gl_checkErr();
}
/**
* @fn void gl_fontInit(glFont* font, const char* fname, const unsigned int h)
*
* @brief Initializes a font.
* @param font Font to load (NULL defaults to gl_defFont).
* @param fname Name of the font (from inside packfile, NULL defaults to default font).
* @param h Height of the font to generate.
*/
void gl_fontInit(glFont* font, const char* fname, const unsigned int h) {
uint32_t bufsize;
int i;
if(font == NULL) font = &gl_defFont;
FT_Byte* buf = pack_readfile(DATA, (fname!=NULL) ? fname : FONT_DEF, &bufsize);
/* Allocatagery. */
font->textures = malloc(sizeof(GLuint)*128);
font->w = malloc(sizeof(int)*128);
font->h = (int)h;
if(font->textures == NULL || font->w == NULL) {
WARN("Out of memory!");
return;
}
/* Create a FreeType font library. */
FT_Library library;
if(FT_Init_FreeType(&library)) {
WARN("FT_Init_FreeType failed");
}
/* Objects that freetype uses to store font info. */
FT_Face face;
if(FT_New_Memory_Face(library, buf, bufsize, 0, &face))
WARN("FT_New_Memory_Face failed loading library from %s", fname);
/* FreeType is pretty nice and measures using 1/64 of a pixel, therfore expand. */
FT_Set_Char_Size(face, h << 6, h << 6, 96, 96);
/* Have OpenGL allocate space for the textures / display lists. */
font->list_base = glGenLists(128);
glGenTextures(128, font->textures);
/* Create each of the font display lists. */
for(i = 0; i < 128; i++)
glFontMakeDList(face, i, font->list_base, font->textures, font->w);
/* We can now free the face and library. */
FT_Done_Face(face);
FT_Done_FreeType(library);
free(buf);
}
/**
* @fn void gl_freeFont(glFont* font)
*
* @brief Free a loaded font.
* @param font Font to free.
*/
void gl_freeFont(glFont* font) {
if(font == NULL) font = &gl_defFont;
glDeleteLists(font->list_base, 128);
glDeleteTextures(128, font->textures);
free(font->textures);
free(font->w);
}
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