draw texture on triangle mesh - libgdx

Question

I am trying to draw a texture on a triangle mesh. I get the mesh but not the picture on it. See on the picture below. As you can see that's a plain triangle but no texture in it.
String vertexShader = "attribute vec4 a_position; \n" +
"attribute vec4 a_color;\n" +
"attribute vec2 a_texCoord0;\n" +
"uniform mat4 u_worldView;\n" +
"varying vec4 v_color;" +
"varying vec2 v_texCoords;" +
"void main() \n" +
"{ \n" +
" v_color = vec4(1, 1, 1, 1); \n" +
" v_texCoords = a_texCoord0; \n" +
" gl_Position = u_worldView * a_position; \n" +
"} \n" ;
String fragmentShader = "#ifdef GL_ES\n" +
"precision mediump float;\n" +
"#endif\n" +
"varying vec4 v_color;\n" +
"varying vec2 v_texCoords;\n" +
"uniform sampler2D u_texture;\n" +
"void main() \n" +
"{ \n" +
" gl_FragColor = v_color * texture2D(u_texture, v_texCoords);\n" +
"}";
shader = new ShaderProgram(vertexShader, fragmentShader);
if (shader.isCompiled() == false) {
Gdx.app.log("ShaderError", shader.getLog());
System.exit(0);
}
mesh = new Mesh(true, 3, 3,
new VertexAttribute(Usage.Position, 3, ShaderProgram.POSITION_ATTRIBUTE),
new VertexAttribute(Usage.Color, 4, ShaderProgram.COLOR_ATTRIBUTE),
new VertexAttribute(Usage.TextureCoordinates, 2, ShaderProgram.TEXCOORD_ATTRIBUTE));
mesh.setVertices(new float[] { -0.5f, -0.5f, 0, 0.2f, 0.3f, 0.4f, 1f, 0, 1,
0.5f, -0.5f, 0, 0.1f, 0.2f, 0.1f, 1f, 1, 1,
0, 0.5f, 0, 0, 0.4f, 0.5f, 0.5f, 1f, 0 });
mesh.setIndices(new short[] { 0, 1, 2 });
texture = new Texture(Gdx.files.internal("data/caveman.png"));
And in my render method:
#Override
public void render () {
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
Gdx.gl.glEnable(GL20.GL_TEXTURE_2D);
texture.bind();
shader.begin();
shader.setUniformMatrix("u_worldView", viewport.getCamera().combined);
shader.setUniformi("u_texture", 0);
mesh.render(shader, GL20.GL_TRIANGLES);
shader.end();
}

Answer 1

Ok I fixed it by changing my shader to
String vertexShader =
"attribute vec4 a_position;\n" +
"attribute vec4 a_color;\n" +
"attribute vec2 a_texCoord;\n" +
"uniform mat4 u_worldView;\n" +
"varying vec4 v_color;\n" +
"varying vec2 v_texCoords;\n" +
"void main()\n" +
"{\n" +
" v_color = vec4(1, 1, 1, 1);\n" +
" v_texCoords = a_texCoord;\n" +
" gl_Position = u_worldView * a_position;\n" +
"}\n" ;
String fragmentShader =
"#ifdef GL_ES\n" +
"precision mediump float;\n" +
"#endif\n" +
"varying vec4 v_color;\n" +
"varying vec2 v_texCoords;\n" +
"uniform sampler2D u_texture;\n" +
"void main()\n" +
"{\n" +
"vec4 texColor = texture2D(u_texture, v_texCoords);\n" +
" gl_FragColor = texColor;\n" +
"}";
Now it draws textures inside the mesh.