love2d.love/src/modules/graphics/opengl/Font.cpp

/**
* Copyright (c) 2006-2011 LOVE Development Team
*
* This software is provided 'as-is', without any express or implied
* warranty.  In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
*    claim that you wrote the original software. If you use this software
*    in a product, an acknowledgment in the product documentation would be
*    appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
*    misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
**/

#include "Font.h"
#include <font/GlyphData.h>
#include "Quad.h"

#include <common/math.h>
#include <math.h>

#include <algorithm> // for max

namespace love
{
namespace graphics
{
namespace opengl
{

	Font::Font(love::font::Rasterizer * r, const Image::Filter& filter)
	: rasterizer(r), height(r->getHeight()), lineHeight(1), mSpacing(1), filter(filter)
	{
		love::font::GlyphData * gd = r->getGlyphData(32);
		type = (gd->getFormat() == love::font::GlyphData::FORMAT_LUMINANCE_ALPHA ? FONT_TRUETYPE : FONT_IMAGE);
		delete gd;
		createTexture();
	}

	Font::~Font()
	{
		unloadVolatile();
	}
	
	void Font::createTexture()
	{
		texture_x = texture_y = rowHeight = 0;
		GLuint t;
		glGenTextures(1, &t);
		textures.push_back(t);
		glBindTexture(GL_TEXTURE_2D, t);
		
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
						(filter.mag == Image::FILTER_LINEAR) ? GL_LINEAR : GL_NEAREST);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
						(filter.min == Image::FILTER_LINEAR) ? GL_LINEAR : GL_NEAREST);
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
		GLint format = (type == FONT_TRUETYPE ? GL_LUMINANCE_ALPHA : GL_RGBA);
		glTexImage2D(GL_TEXTURE_2D, 
					 0, 
					 GL_RGBA, 
					 (GLsizei)TEXTURE_WIDTH, 
					 (GLsizei)TEXTURE_HEIGHT, 
					 0, 
					 format, 
					 GL_UNSIGNED_BYTE, 
					 NULL);
	}
	
	Font::Glyph * Font::addGlyph(int glyph)
	{
		Glyph * g = new Glyph;
		g->list = glGenLists(1);
		if (g->list == 0) { // opengl failed to generate the list
			delete g;
			return NULL;
		}
		love::font::GlyphData *gd = rasterizer->getGlyphData(glyph);
		g->spacing = gd->getAdvance();
		int w = gd->getWidth();
		int h = gd->getHeight();
		if (texture_x + w > TEXTURE_WIDTH) { // out of space - new row!
			texture_x = 0;
			texture_y += rowHeight;
			rowHeight = 0;
		}
		if (texture_y + h > TEXTURE_HEIGHT) { // totally out of space - new texture!
			createTexture();
		}
		GLuint t = textures.back();
		glBindTexture(GL_TEXTURE_2D, t);
		glTexSubImage2D(GL_TEXTURE_2D, 0, texture_x, texture_y, w, h, (type == FONT_TRUETYPE ? GL_LUMINANCE_ALPHA : GL_RGBA), GL_UNSIGNED_BYTE, gd->getData());
		
		Quad::Viewport v;
		v.x = texture_x;
		v.y = texture_y;
		v.w = w;
		v.h = h;
		Quad * q = new Quad(v, TEXTURE_WIDTH, TEXTURE_HEIGHT);
		const vertex * verts = q->getVertices();
		
		glEnableClientState(GL_VERTEX_ARRAY);
		glEnableClientState(GL_TEXTURE_COORD_ARRAY);
		glVertexPointer(2, GL_FLOAT, sizeof(vertex), (GLvoid *)&verts[0].x);
		glTexCoordPointer(2, GL_FLOAT, sizeof(vertex), (GLvoid *)&verts[0].s);
		
		glNewList(g->list, GL_COMPILE);
		glBindTexture(GL_TEXTURE_2D, t);
		glPushMatrix();
		glTranslatef(static_cast<float>(gd->getBearingX()), static_cast<float>(-gd->getBearingY()), 0.0f);
		glDrawArrays(GL_QUADS, 0, 4);
		glPopMatrix();
		glEndList();
		
		glDisableClientState(GL_TEXTURE_COORD_ARRAY);
		glDisableClientState(GL_VERTEX_ARRAY);
		
		delete q;
		delete gd;
		
		texture_x += w;
		rowHeight = std::max(rowHeight, h);
		
		glyphs[glyph] = g;
		return g;
	}

	float Font::getHeight() const
	{
		return static_cast<float>(height);
	}

	void Font::print(std::string text, float x, float y, float angle, float sx, float sy)
	{
		float dx = 0.0f; // spacing counter for newline handling
		glPushMatrix();

		glTranslatef(ceil(x), ceil(y), 0.0f);
		glRotatef(LOVE_TODEG(angle), 0, 0, 1.0f);
		glScalef(sx, sy, 1.0f);
		for (unsigned int i = 0; i < text.size(); i++) {
			unsigned char g = (unsigned char)text[i];
			if (g == '\n') { // wrap newline, but do not print it
				glTranslatef(-dx, floor(getHeight() * getLineHeight() + 0.5f), 0);
				dx = 0.0f;
				continue;
			}
			Glyph * glyph = glyphs[g];
			if (!glyph) glyph = addGlyph(g);
			glPushMatrix();
			// 1.25 is magic line height for true type fonts
			if (type == FONT_TRUETYPE) glTranslatef(0, floor(getHeight() / 1.25f + 0.5f), 0);
			glCallList(glyph->list);
			glPopMatrix();
			glTranslatef(static_cast<GLfloat>(glyph->spacing), 0, 0);
			dx += glyph->spacing;
		}
		glPopMatrix();
	}

	void Font::print(char character, float x, float y)
	{
		Glyph * glyph = glyphs[character];
		if (!glyph) glyph = addGlyph(character);
		glPushMatrix();
		glTranslatef(x, floor(y+getHeight() + 0.5f), 0.0f);
		glCallList(glyph->list);
		glPopMatrix();
	}

	int Font::getWidth(const std::string & line)
	{
		if(line.size() == 0) return 0;
		int temp = 0;
		
		Glyph * g;

		for(unsigned int i = 0; i < line.size(); i++)
		{
			g = glyphs[line[i]];
			if (!g) g = addGlyph(line[i]);
			temp += static_cast<int>(g->spacing * mSpacing);
		}

		return temp;
	}

	int Font::getWidth(const char * line)
	{
		return this->getWidth(std::string(line));
	}

	int Font::getWidth(const char character)
	{
		Glyph * g = glyphs[character];
		if (!g) g = addGlyph(character);
		return g->spacing;
	}

	int Font::getWrap(const std::string & line, float wrap, int * lines)
	{
		if(line.size() == 0) return 0;
		int maxw = 0;
		int linen = 1;
		int temp = 0;
		std::string text;
		Glyph * g;

		for(unsigned int i = 0; i < line.size(); i++)
		{
			if(temp > wrap && text.find(" ") != std::string::npos)
			{
				unsigned int space = text.find_last_of(' ');
				std::string tmp = text.substr(0, space);
				int w = getWidth(tmp);
				if(w > maxw) maxw = w;
				text = text.substr(space+1);
				temp = getWidth(text);
				linen++;
			}
			g = glyphs[line[i]];
			if (!g) g = addGlyph(line[i]);
			temp += static_cast<int>(g->spacing * mSpacing);
			text += line[i];
		}

		if(temp > maxw) maxw = temp;
		if(lines) *lines = linen;

		return maxw;
	}

	int Font::getWrap(const char * line, float wrap, int * lines)
	{
		return getWrap(std::string(line), wrap, lines);
	}

	void Font::setLineHeight(float height)
	{
		this->lineHeight = height;
	}

	float Font::getLineHeight() const
	{
		return lineHeight;
	}

	void Font::setSpacing(float amount)
	{
		mSpacing = amount;
	}

	float Font::getSpacing() const
	{
		return mSpacing;
	}

	bool Font::loadVolatile()
	{
		createTexture();
		return true;
	}

	void Font::unloadVolatile()
	{
		// nuke everything from orbit
		std::map<int, Glyph *>::iterator it = glyphs.begin();
		Glyph * g;
		while (it != glyphs.end()) {
			g = it->second;
			glDeleteLists(g->list, 1);
			delete g;
			glyphs.erase(it++);
		}
		std::vector<GLuint>::iterator iter = textures.begin();
		while (iter != textures.end()) {
			glDeleteTextures(1, (GLuint*)&*iter);
			iter++;
		}
		textures.clear();
	}

} // opengl
} // graphics
} // love