vmap/libs/gtkutil/glfont.cpp

/*
   Copyright (C) 2001-2006, William Joseph.
   All Rights Reserved.

   This file is part of GtkRadiant.

   GtkRadiant 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.

   GtkRadiant is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "glfont.h"
#include "globaldefs.h"
#include "igl.h"

// generic string printing with call lists
class GLFontCallList : public GLFont {
GLuint m_displayList;
int m_pixelHeight;
int m_pixelAscent;
int m_pixelDescent;
public:
GLFontCallList(GLuint displayList, int asc, int desc, int pixelHeight) : m_displayList(displayList),
	m_pixelHeight(pixelHeight),
	m_pixelAscent(asc), m_pixelDescent(desc)
{
}

virtual ~GLFontCallList()
{
	glDeleteLists(m_displayList, 256);
}

void printString(const char *s)
{
	GlobalOpenGL().m_glListBase(m_displayList);
	GlobalOpenGL().m_glCallLists(GLsizei(strlen(s)), GL_UNSIGNED_BYTE, reinterpret_cast<const GLubyte *>( s ));
}

virtual int getPixelAscent() const
{
	return m_pixelAscent;
}

virtual int getPixelDescent() const
{
	return m_pixelDescent;
}

virtual int getPixelHeight() const
{
	return m_pixelHeight;
}
};

#if GDEF_OS_WINDOWS
#include <windows.h>
#endif

#include "debugging/debugging.h"

// LordHavoc: this is code for direct Xlib bitmap character fetching, as an
// alternative to requiring gtkglarea, it was created due to a lack of this
// package on SuSE 9.x but this package is now commonly shipping in Linux
// distributions so this code may be unnecessary, feel free however to enable
// it when building packages for distros that do not ship with that package,
// or if you just prefer less dependencies...
#if 0

#include <X11/Xlib.h>
#include <gdk/gdkx.h>
#include <GL/glx.h>

GLFont *glfont_create( const char* font_string ){
	GLuint font_list_base;
	XFontStruct *fontInfo;
	Display *dpy = GDK_DISPLAY();
	unsigned int i, first, last, firstrow, lastrow;
	int maxchars;
	int firstbitmap;

	fontInfo = XLoadQueryFont( dpy, "-*-fixed-*-*-*-*-8-*-*-*-*-*-*-*" );
	if ( fontInfo == NULL ) {
		// try to load other fonts
		fontInfo = XLoadQueryFont( dpy, "-*-fixed-*-*-*-*-*-*-*-*-*-*-*-*" );

		// any font will do !
		if ( fontInfo == NULL ) {
			fontInfo = XLoadQueryFont( dpy, "-*-*-*-*-*-*-*-*-*-*-*-*-*-*" );
		}

		if ( fontInfo == NULL ) {
			ERROR_MESSAGE( "couldn't create font" );
		}
	}

	first = (int)fontInfo->min_char_or_byte2;
	last = (int)fontInfo->max_char_or_byte2;
	firstrow = (int)fontInfo->min_byte1;
	lastrow = (int)fontInfo->max_byte1;
	/*
	 * How many chars in the charset
	 */
	maxchars = 256 * lastrow + last;
	font_list_base = glGenLists( maxchars + 1 );
	if ( font_list_base == 0 ) {
		ERROR_MESSAGE( "couldn't create font" );
	}

	/*
	 * Get offset to first char in the charset
	 */
	firstbitmap = 256 * firstrow + first;
	/*
	 * for each row of chars, call glXUseXFont to build the bitmaps.
	 */

	for ( i = firstrow; i <= lastrow; i++ )
	{
		glXUseXFont( fontInfo->fid, firstbitmap, last - first + 1, font_list_base + firstbitmap );
		firstbitmap += 256;
	}

/*    *height = fontInfo->ascent + fontInfo->descent;
 * width = fontInfo->max_bounds.width;  */
	return new GLFontCallList( font_list_base, fontInfo->ascent, fontInfo->descent, fontInfo->ascent + fontInfo->descent );
}

#elif 0

#include <gtk/gtkglwidget.h>

GLFont *glfont_create( const char* font_string ){
	GLuint font_list_base = glGenLists( 256 );
	gint font_height = 0, font_ascent = 0, font_descent = 0;

	PangoFontDescription* font_desc = pango_font_description_from_string( font_string );

	PangoFont* font = gdk_gl_font_use_pango_font( font_desc, 0, 256, font_list_base );

	if ( font == 0 ) {
		pango_font_description_free( font_desc );
		font_desc = pango_font_description_from_string( "fixed 8" );
		font = gdk_gl_font_use_pango_font( font_desc, 0, 256, font_list_base );
	}

	if ( font == 0 ) {
		pango_font_description_free( font_desc );
		font_desc = pango_font_description_from_string( "courier new 8" );
		font = gdk_gl_font_use_pango_font( font_desc, 0, 256, font_list_base );
	}

	if ( font != 0 ) {
		PangoFontMetrics* font_metrics = pango_font_get_metrics( font, 0 );

		font_ascent = pango_font_metrics_get_ascent( font_metrics );
		font_descent = pango_font_metrics_get_descent( font_metrics );
		font_height = font_ascent + font_descent;

		font_ascent = PANGO_PIXELS( font_ascent );
		font_descent = PANGO_PIXELS( font_descent );
		font_height = PANGO_PIXELS( font_height );

		pango_font_metrics_unref( font_metrics );
	}

	pango_font_description_free( font_desc );

	// fix for pango/gtkglext metrix bug
	if ( font_height > 256 ) {
		font_height = 16;
	}

	return new GLFontCallList( font_list_base, font_ascent, font_descent, font_height );
}
#else

// new font code ripped from ZeroRadiant

#include <pango/pangoft2.h>
#include <pango/pango-features.h>
#include <pango/pango-utils.h>

class GLFontInternal : public GLFont {
const char *font_string;
int font_height;
int font_ascent;
int font_descent;
int y_offset_bitmap_render_pango_units;
PangoContext *ft2_context;
PangoFontMap *fontmap;

public:
GLFontInternal(const char *_font_string) : font_string(_font_string)
{
	PangoFontDescription *font_desc;
	PangoLayout *layout;
	PangoRectangle log_rect;
	int font_ascent_pango_units;
	int font_descent_pango_units;

#if !PANGO_VERSION_CHECK(1, 22, 0)
	ft2_context = pango_ft2_get_context( 72, 72 );
#else
	fontmap = pango_ft2_font_map_new();
	pango_ft2_font_map_set_resolution(PANGO_FT2_FONT_MAP(fontmap), 72, 72);
	ft2_context = pango_font_map_create_context(fontmap);
#endif

	font_desc = pango_font_description_from_string( "Liberation Mono 12" );
	//pango_font_description_set_size(font_desc, 10 * PANGO_SCALE);
	pango_context_set_font_description(ft2_context, font_desc);
	pango_font_description_free(font_desc);
	// TODO fallback to fixed 8, courier new 8

	layout = pango_layout_new(ft2_context);

#ifdef FONT_SIZE_WORKAROUND
	pango_layout_set_width( layout, -1 );   // -1 no wrapping.  All text on one line.
	pango_layout_set_text( layout, "The quick brown fox jumped over the lazy sleeping dog's back then sat on a tack.", -1 );   // -1 null-terminated string.
#endif

#if !PANGO_VERSION_CHECK(1, 22, 0)
	PangoLayoutIter *iter;
	iter = pango_layout_get_iter( layout );
	font_ascent_pango_units = pango_layout_iter_get_baseline( iter );
	pango_layout_iter_free( iter );
#else
	font_ascent_pango_units = pango_layout_get_baseline(layout);
#endif
	pango_layout_get_extents(layout, NULL, &log_rect);
	g_object_unref(G_OBJECT(layout));
	font_descent_pango_units = log_rect.height - font_ascent_pango_units;

	font_ascent = PANGO_PIXELS_CEIL(font_ascent_pango_units);
	font_descent = PANGO_PIXELS_CEIL(font_descent_pango_units);
	font_height = font_ascent + font_descent;
	y_offset_bitmap_render_pango_units = (font_ascent * PANGO_SCALE) - font_ascent_pango_units;
}

virtual ~GLFontInternal()
{
	g_object_unref(G_OBJECT(ft2_context));
	g_object_unref(G_OBJECT(fontmap));
}

// Renders the input text at the current location with the current color.
// The X position of the current location is used to place the left edge of the text image,
// where the text image bounds are defined as the logical extents of the line of text.
// The Y position of the current location is used to place the bottom of the text image.
// You should offset the Y position by the amount returned by gtk_glwidget_font_descent()
// if you want to place the baseline of the text image at the current Y position.
// Note: A problem with this function is that if the lower left corner of the text falls
// just a hair outside of the viewport (meaning the current raster position is invalid),
// then no text will be rendered.  The solution to this is a very hacky one.  You can search
// Google for "glDrawPixels clipping".
virtual void printString(const char *s)
{
	// The idea for this code initially came from the font-pangoft2.c example that comes with GtkGLExt.

	PangoLayout *layout;
	PangoRectangle log_rect;
	FT_Bitmap bitmap;
	unsigned char *begin_bitmap_buffer;
	GLfloat color[4];
	GLint previous_unpack_alignment;
	GLboolean previous_blend_enabled;
	GLint previous_blend_func_src;
	GLint previous_blend_func_dst;
	GLfloat previous_red_bias;
	GLfloat previous_green_bias;
	GLfloat previous_blue_bias;
	GLfloat previous_alpha_scale;

	layout = pango_layout_new(ft2_context);
	pango_layout_set_width(layout, -1);   // -1 no wrapping.  All text on one line.
	pango_layout_set_text(layout, s, -1);   // -1 null-terminated string.
	pango_layout_get_extents(layout, NULL, &log_rect);

	if (log_rect.width > 0 && log_rect.height > 0) {
		bitmap.rows = font_ascent + font_descent;
		bitmap.width = PANGO_PIXELS_CEIL(log_rect.width);
		bitmap.pitch = -bitmap.width; // Rendering it "upside down" for OpenGL.
		begin_bitmap_buffer = (unsigned char *) g_malloc(bitmap.rows * bitmap.width);
		memset(begin_bitmap_buffer, 0, bitmap.rows * bitmap.width);
		bitmap.buffer = begin_bitmap_buffer + (bitmap.rows - 1) * bitmap.width; // See pitch above.
		bitmap.num_grays = 0xff;
		bitmap.pixel_mode = FT_PIXEL_MODE_GRAY;
		pango_ft2_render_layout_subpixel(&bitmap, layout, -log_rect.x,
		                                 y_offset_bitmap_render_pango_units);
		GlobalOpenGL().m_glGetFloatv(GL_CURRENT_COLOR, color);

		// Save state.  I didn't see any OpenGL push/pop operations for these.
		// Question: Is saving/restoring this state necessary?  Being safe.
		GlobalOpenGL().m_glGetIntegerv(GL_UNPACK_ALIGNMENT, &previous_unpack_alignment);
		previous_blend_enabled = GlobalOpenGL().m_glIsEnabled(GL_BLEND);
		GlobalOpenGL().m_glGetIntegerv(GL_BLEND_SRC, &previous_blend_func_src);
		GlobalOpenGL().m_glGetIntegerv(GL_BLEND_DST, &previous_blend_func_dst);
		GlobalOpenGL().m_glGetFloatv(GL_RED_BIAS, &previous_red_bias);
		GlobalOpenGL().m_glGetFloatv(GL_GREEN_BIAS, &previous_green_bias);
		GlobalOpenGL().m_glGetFloatv(GL_BLUE_BIAS, &previous_blue_bias);
		GlobalOpenGL().m_glGetFloatv(GL_ALPHA_SCALE, &previous_alpha_scale);

		GlobalOpenGL().m_glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
		GlobalOpenGL().m_glEnable(GL_BLEND);
		GlobalOpenGL().m_glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
		GlobalOpenGL().m_glPixelTransferf(GL_RED_BIAS, color[0]);
		GlobalOpenGL().m_glPixelTransferf(GL_GREEN_BIAS, color[1]);
		GlobalOpenGL().m_glPixelTransferf(GL_BLUE_BIAS, color[2]);
		GlobalOpenGL().m_glPixelTransferf(GL_ALPHA_SCALE, color[3]);

		GlobalOpenGL().m_glDrawPixels(bitmap.width, bitmap.rows,
		                              GL_ALPHA, GL_UNSIGNED_BYTE, begin_bitmap_buffer);
		g_free(begin_bitmap_buffer);

		// Restore state in reverse order of how we set it.
		GlobalOpenGL().m_glPixelTransferf(GL_ALPHA_SCALE, previous_alpha_scale);
		GlobalOpenGL().m_glPixelTransferf(GL_BLUE_BIAS, previous_blue_bias);
		GlobalOpenGL().m_glPixelTransferf(GL_GREEN_BIAS, previous_green_bias);
		GlobalOpenGL().m_glPixelTransferf(GL_RED_BIAS, previous_red_bias);
		GlobalOpenGL().m_glBlendFunc(previous_blend_func_src, previous_blend_func_dst);
		if (!previous_blend_enabled) {
			GlobalOpenGL().m_glDisable(GL_BLEND);
		}
		GlobalOpenGL().m_glPixelStorei(GL_UNPACK_ALIGNMENT, previous_unpack_alignment);
	}

	g_object_unref(G_OBJECT(layout));
}

virtual int getPixelAscent() const
{
	return font_ascent;
}

virtual int getPixelDescent() const
{
	return font_descent;
}

virtual int getPixelHeight() const
{
	return font_height;
}
};

GLFont *glfont_create(const char *font_string)
{
	return new GLFontInternal(font_string);
}

#endif