com.badlogic.gdx.tests.gles2.SimpleVertexShader.java Source code

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Here is the source code for com.badlogic.gdx.tests.gles2.SimpleVertexShader.java

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/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

package com.badlogic.gdx.tests.gles2;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Mesh;
import com.badlogic.gdx.graphics.VertexAttributes.Usage;
import com.badlogic.gdx.graphics.glutils.ShaderProgram;
import com.badlogic.gdx.math.Matrix4;
import com.badlogic.gdx.math.Vector3;
import com.badlogic.gdx.tests.utils.GdxTest;

public class SimpleVertexShader extends GdxTest {
    ShaderProgram shader;
    Mesh mesh;
    Matrix4 projection = new Matrix4();
    Matrix4 view = new Matrix4();
    Matrix4 model = new Matrix4();
    Matrix4 combined = new Matrix4();
    Vector3 axis = new Vector3(1, 0, 1).nor();
    float angle = 45;

    @Override
    public void create() {
        // @off
        String vertexShader = "uniform mat4 u_mvpMatrix;                   \n"
                + "attribute vec4 a_position;                  \n"
                + "void main()                                 \n"
                + "{                                           \n"
                + "   gl_Position = u_mvpMatrix * a_position;  \n" + "}                            \n";
        String fragmentShader = "#ifdef GL_ES\n" + "precision mediump float;\n" + "#endif\n"
                + "void main()                                  \n"
                + "{                                            \n"
                + "  gl_FragColor = vec4 ( 1.0, 0.0, 0.0, 1.0 );\n" + "}";
        // @on

        shader = new ShaderProgram(vertexShader, fragmentShader);
        mesh = Shapes.genCube();
        mesh.getVertexAttribute(Usage.Position).alias = "a_position";
    }

    @Override
    public void render() {
        angle += Gdx.graphics.getDeltaTime() * 40.0f;
        float aspect = Gdx.graphics.getWidth() / (float) Gdx.graphics.getHeight();
        projection.setToProjection(1.0f, 20.0f, 60.0f, aspect);
        view.idt().trn(0, 0, -2.0f);
        model.setToRotation(axis, angle);
        combined.set(projection).mul(view).mul(model);

        Gdx.gl20.glViewport(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
        Gdx.gl20.glClear(GL20.GL_COLOR_BUFFER_BIT);
        shader.begin();
        shader.setUniformMatrix("u_mvpMatrix", combined);
        mesh.render(shader, GL20.GL_TRIANGLES);
        shader.end();

        Gdx.app.log("angle", "" + angle);
    }
}