Android Open Source - RageTextSample-Android-Java R A G E Sample Renderer

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License

The source code is released under:

MIT License

Java Source Code

package de.ertlu.rob.ragesamplebase;
//from  w w  w  . ja v a  2s .  co  m
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView;
import android.opengl.GLUtils;
import android.opengl.Matrix;

import java.io.IOException;
import java.io.InputStream;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;

import de.ertlu.rob.Rage.Common.Rage;
import de.ertlu.rob.Rage.Shader.Shader;
import de.ertlu.rob.Rage.Text.Font;
import de.ertlu.rob.Rage.Text.FontShader;
import de.ertlu.rob.Rage.Text.Text;

/**
 * @author Robert Lude : rob@ertlu.de
 */
public class RAGESampleRenderer implements GLSurfaceView.Renderer {
    private static final String TAG = RAGESampleRenderer.class.getName();
    private static final float[] screenMatrix = new float[16];

    private Font font;

    private Text textA;
    private Text textB;
    private Text textC;
    private Text textD;

    public void onSurfaceCreated(GL10 gl, EGLConfig config) {
        GLES20.glDisable(GLES20.GL_CULL_FACE);
        Rage.checkGLError(TAG, "onSurfaceCreated", "glDisable");

        GLES20.glDisable(GLES20.GL_DEPTH_TEST);
        Rage.checkGLError(TAG, "onSurfaceCreated", "glDisable");

        GLES20.glEnable(GLES20.GL_BLEND);
        Rage.checkGLError(TAG, "onSurfaceCreated", "glEnable");

        GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE_MINUS_SRC_ALPHA);
        Rage.checkGLError(TAG, "onSurfaceCreated", "glBlendFunc");

        GLES20.glBlendEquation(GLES20.GL_FUNC_ADD);
        Rage.checkGLError(TAG, "onSurfaceCreated", "glBlendEquation");

        GLES20.glClearColor(0, 0, 0, 1);
        Rage.checkGLError(TAG, "onSurfaceCreated", "glClearColor");

        // This call lets the font shader know that the OpenGL context has been reset
        FontShader.resetInstance();

        font = loadFont("Roboto-Medium");
    }

    @Override
    public void onSurfaceChanged(GL10 gl, int width, int height) {
        calculateScreenMatrix(width, height);

        final float textSize = height * 0.1f;
        final String loremIpsum = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut fringilla sit amet risus ut tempor. Sed lacinia enim vitae hendrerit sodales. Duis interdum vel nunc.";

        textA = new Text(font, loremIpsum, 0, 0, textSize, new float[]{1,0,0,1});
        textB = textA.setPosition(textSize, textSize).setColor(new float[]{1,1,0,1});
        textC = textA.setSize(textSize * 2).setPosition(0, textSize * 2).setColor(new float[]{0,1,0,1});
        textD = textA.setText("Goodbye, tutorial!").setPosition(0, height - textSize).setColor(new float[]{0,0,1,1});
    }

    @Override
    public void onDrawFrame(GL10 gl) {
        final String method = "onDrawFrame";

        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
        Rage.checkGLError(TAG, method, "glClear");

        if ( textA == null ) return;
        Shader.setViewMatrix(screenMatrix);
        textA.draw();
        textB.draw();
        textC.draw();
        textD.draw();
    }

    private void calculateScreenMatrix(final float width, final float height) {
        float[] a = new float[16];
        float[] b = new float[16];
        Matrix.orthoM(a, 0, 0, width, height, 0, -1, 50);
        Matrix.setLookAtM(b, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0);
        Matrix.multiplyMM(screenMatrix,0, a,0, b,0);
    }

    private static final Font loadFont(final String name) {
        // This is so we don't have to type the method name for every call to checkGLError
        // This also prevents method name mistakes on our part from copying and pasting code to a different method
        final String method = "loadFont";

        // First, create an array to store the ids of the new textures
        // We only need one, but we still need an array.
        final int[] textureId = new int[1];

        // This is the actual call that creates the new texture ids
        GLES20.glGenTextures(1, textureId, 0);
        Rage.checkGLError(TAG, method, "glGenTextures");

        // We are going to assume everything went ok for the purposes of this tutorial

        // The BitmapFactory helper takes an object that is full of options for constructing the
        // bitmap. We are only concerned with 'inScaled' which determines whether or not the image
        // will be resized upon reading. We don't want that.
        BitmapFactory.Options bitmapFactoryOptions = new BitmapFactory.Options();
        bitmapFactoryOptions.inScaled = false;

        // Try opening the bitmap asset. Remember, we're not really handling errors here properly
        InputStream inputStream;
        try {
            inputStream = RAGESampleActivity.instance.getAssets().open(name + ".png");
        } catch (IOException e) {
            return null;
        }

        // Decode the stream into a bitmap in system memory
        Bitmap bitmap = BitmapFactory.decodeStream(inputStream);

        // Close the input stream now that we are done with it
        try {
            inputStream.close();
        } catch (IOException e) {
            return null;
        }

        // Bind the texture we are loading and set some basic filtering parameters
        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId[0]);
        Rage.checkGLError(TAG, method, "glBindTexture");
        GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
        Rage.checkGLError(TAG, method, "glTexParameteri");
        GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST);
        Rage.checkGLError(TAG, method, "glTexParameteri");

        // Use GLUtils to copy the bitmap from system memory to GPU memory
        GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);

        // Get rid of the system copy
        bitmap.recycle();

        // Now we need to get a stream to the .glyphData file
        try {
            inputStream = RAGESampleActivity.instance.getAssets().open(name + ".glyphData");
        } catch (IOException e) {
            return null;
        }

        // At last we can create the new Font object!
        Font result = new Font(textureId[0], inputStream);

        // Close up that .glyphData stream before we go...
        try {
            inputStream.close();
        } catch (IOException e) {
            return null;
        }

        // Return the resulting font object
        return result;
    }
}

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