com.badlogic.gdx.tests.gles2.MipMap2D.java Source code

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Here is the source code for com.badlogic.gdx.tests.gles2.MipMap2D.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.Pixmap;
import com.badlogic.gdx.graphics.Pixmap.Format;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.Texture.TextureFilter;
import com.badlogic.gdx.graphics.VertexAttribute;
import com.badlogic.gdx.graphics.VertexAttributes.Usage;
import com.badlogic.gdx.graphics.glutils.ShaderProgram;
import com.badlogic.gdx.tests.utils.GdxTest;

public class MipMap2D extends GdxTest {
    ShaderProgram shader;
    Texture texture;
    Mesh mesh;

    @Override
    public void create() {
        String vertexShader = "uniform float u_offset;      \n" + "attribute vec4 a_position;   \n"
                + "attribute vec2 a_texCoord;   \n" + "varying vec2 v_texCoord;     \n"
                + "void main()                  \n" + "{                            \n"
                + "   gl_Position = a_position; \n" + "   gl_Position.x += u_offset;\n"
                + "   v_texCoord = a_texCoord;  \n" + "}                            \n";
        String fragmentShader = "#ifdef GL_ES\n" + "precision mediump float;\n" + "#endif\n"
                + "varying vec2 v_texCoord;                            \n"
                + "uniform sampler2D s_texture;                        \n"
                + "void main()                                         \n"
                + "{                                                   \n"
                + "  gl_FragColor = texture2D( s_texture, v_texCoord );\n"
                + "}                                                   \n";
        shader = new ShaderProgram(vertexShader, fragmentShader);
        mesh = new Mesh(true, 4, 6, new VertexAttribute(Usage.Position, 4, "a_position"),
                new VertexAttribute(Usage.TextureCoordinates, 2, "a_texCoord"));
        float[] vertices = { -0.5f, 0.5f, 0.0f, 1.5f, // Position 0
                0.0f, 0.0f, // TexCoord 0
                -0.5f, -0.5f, 0.0f, 0.75f, // Position 1
                0.0f, 1.0f, // TexCoord 1
                0.5f, -0.5f, 0.0f, 0.75f, // Position 2
                1.0f, 1.0f, // TexCoord 2
                0.5f, 0.5f, 0.0f, 1.5f, // Position 3
                1.0f, 0.0f // TexCoord 3
        };
        short[] indices = { 0, 1, 2, 0, 2, 3 };
        mesh.setVertices(vertices);
        mesh.setIndices(indices);
        createTexture();
    }

    private void createTexture() {
        Pixmap pixmap = new Pixmap(256, 256, Format.RGB565);
        boolean useRed = true;
        for (int y = 0; y < 256; y += 8) {
            for (int x = 0; x < 256; x += 8) {
                pixmap.setColor(useRed ? 1 : 0, 0, useRed ? 0 : 1, 1);
                pixmap.fillRectangle(x, y, 8, 8);
                useRed = !useRed;
            }
            useRed = !useRed;
        }
        texture = new Texture(pixmap, true);
        texture.setFilter(TextureFilter.MipMapLinearLinear, TextureFilter.Linear);
    }

    public void resume() {
        createTexture();
    }

    public void render() {
        Gdx.gl20.glViewport(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
        Gdx.gl20.glClear(GL20.GL_COLOR_BUFFER_BIT);

        Gdx.gl20.glActiveTexture(GL20.GL_TEXTURE0);
        texture.bind();
        shader.begin();
        shader.setUniformf("s_texture", 0);

        Gdx.gl20.glTexParameteri(GL20.GL_TEXTURE_2D, GL20.GL_TEXTURE_MIN_FILTER, GL20.GL_NEAREST);
        shader.setUniformf("u_offset", -0.6f);
        mesh.render(shader, GL20.GL_TRIANGLES);

        Gdx.gl20.glTexParameteri(GL20.GL_TEXTURE_2D, GL20.GL_TEXTURE_MIN_FILTER, GL20.GL_LINEAR_MIPMAP_LINEAR);
        shader.setUniformf("u_offset", 0.6f);
        mesh.render(shader, GL20.GL_TRIANGLES);

        shader.end();
    }
}