BasicTest.java

package com.himamis.retex.renderer.desktop;

import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;

import javax.imageio.ImageIO;

import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;

import com.himamis.retex.renderer.desktop.FactoryProviderDesktop;
import com.himamis.retex.renderer.desktop.graphics.ImageD;
import com.himamis.retex.renderer.share.ColorUtil;
import com.himamis.retex.renderer.share.TeXConstants;
import com.himamis.retex.renderer.share.TeXFormula;
import com.himamis.retex.renderer.share.TeXIcon;
import com.himamis.retex.renderer.share.platform.FactoryProvider;
import com.himamis.retex.renderer.share.platform.graphics.Graphics2DInterface;
import com.himamis.retex.renderer.share.platform.graphics.Image;
import com.himamis.retex.renderer.share.platform.graphics.Insets;

public class BasicTest {

	@BeforeClass
	public static void setFactory() {
		FactoryProvider.setInstance(new FactoryProviderDesktop());
	}
	
	@Test
	public static void basicExample2() {
		String latex = "\\begin{array}{l}";
		latex += "\\forall\\varepsilon\\in\\mathbb{R}_+^*\\ \\exists\\eta>0\\ |x-x_0|\\leq\\eta\\Longrightarrow|f(x)-f(x_0)|\\leq\\varepsilon\\\\";
		latex += "\\det\\begin{bmatrix}a_{11}&a_{12}&\\cdots&a_{1n}\\\\a_{21}&\\ddots&&\\vdots\\\\\\vdots&&\\ddots&\\vdots\\\\a_{n1}&\\cdots&\\cdots&a_{nn}\\end{bmatrix}\\overset{\\mathrm{def}}{=}\\sum_{\\sigma\\in\\mathfrak{S}_n}\\varepsilon(\\sigma)\\prod_{k=1}^n a_{k\\sigma(k)}\\\\";
		latex += "\\sideset{_\\alpha^\\beta}{_\\gamma^\\delta}{\\begin{pmatrix}a&b\\\\c&d\\end{pmatrix}}\\\\";
		latex += "\\int_0^\\infty{x^{2n} e^{-a x^2}\\,dx} = \\frac{2n-1}{2a} \\int_0^\\infty{x^{2(n-1)} e^{-a x^2}\\,dx} = \\frac{(2n-1)!!}{2^{n+1}} \\sqrt{\\frac{\\pi}{a^{2n+1}}}\\\\";
		latex += "\\int_a^b{f(x)\\,dx} = (b - a) \\sum\\limits_{n = 1}^\\infty  {\\sum\\limits_{m = 1}^{2^n  - 1} {\\left( { - 1} \\right)^{m + 1} } } 2^{ - n} f(a + m\\left( {b - a} \\right)2^{-n} )\\\\";
		latex += "\\int_{-\\pi}^{\\pi} \\sin(\\alpha x) \\sin^n(\\beta x) dx = \\textstyle{\\left \\{ \\begin{array}{cc} (-1)^{(n+1)/2} (-1)^m \\frac{2 \\pi}{2^n} \\binom{n}{m} & n \\mbox{ odd},\\ \\alpha = \\beta (2m-n) \\\\ 0 & \\mbox{otherwise} \\\\ \\end{array} \\right .}\\\\";
		latex += "L = \\int_a^b \\sqrt{ \\left|\\sum_{i,j=1}^ng_{ij}(\\gamma(t))\\left(\\frac{d}{dt}x^i\\circ\\gamma(t)\\right)\\left(\\frac{d}{dt}x^j\\circ\\gamma(t)\\right)\\right|}\\,dt\\\\";
		latex += "\\begin{array}{rl} s &= \\int_a^b\\left\\|\\frac{d}{dt}\\vec{r}\\,(u(t),v(t))\\right\\|\\,dt \\\\ &= \\int_a^b \\sqrt{u'(t)^2\\,\\vec{r}_u\\cdot\\vec{r}_u + 2u'(t)v'(t)\\, \\vec{r}_u\\cdot\\vec{r}_v+ v'(t)^2\\,\\vec{r}_v\\cdot\\vec{r}_v}\\,\\,\\, dt. \\end{array}\\\\";
		latex += "\\end{array}";
		
		doTest(latex, "Basic/Example2");
	}

	private static void doTest(String latex, String exampleName) {
		TeXIcon icon = createTeXIcon(latex);
		Image image = createImage(icon);
		byte[] imageBytes = getImageBytes(image);
		byte[] expectedBytes = loadResourceFile(exampleName + ".png");
		Assert.assertArrayEquals(expectedBytes, imageBytes);
	}
	
	private static TeXIcon createTeXIcon(String latex) {
		TeXFormula formula = null;
		try {
			formula = new TeXFormula(latex);
		} catch (Throwable e) {
			e.printStackTrace();
		}
		TeXIcon icon = formula.new TeXIconBuilder().setStyle(TeXConstants.STYLE_DISPLAY).setSize(20).build();

		icon.setInsets(new Insets(5, 5, 5, 5));
		return icon;
	}

	private static Image createImage(TeXIcon icon) {
		Image image = new ImageD(icon.getIconWidth(), icon.getIconHeight(), Image.TYPE_INT_ARGB);
		Graphics2DInterface g2 = image.createGraphics2D();
		g2.setColor(ColorUtil.WHITE);
		g2.fillRect(0, 0, icon.getIconWidth(), icon.getIconHeight());
		icon.paintIcon(null, g2, 0, 0);
		return image;
	}

	private static byte[] getImageBytes(Image image) {
		ByteArrayOutputStream os = new ByteArrayOutputStream();
		try {
			ImageIO.write((BufferedImage) image, "png", os);
		} catch (IOException ex) {
		}
		return os.toByteArray();
	}

	private static byte[] loadResourceFile(String name) {
		String path = ClassLoader.getSystemResource(name).getFile().substring(1);
		try {
			return Files.readAllBytes(Paths.get(path));
		} catch (IOException e) {
			return new byte[1];
		}
	}

}