/**
* Prepare a RenderToTexture target of the given width x height that will be used as the rendering
* target for the texture atlas algorithm.
*
* @param width width of the texture
* @param height height of the texture
*/
public CoreTextureAtlasGenerator(final CoreGL gl, final int width, final int height) {
coreRender = CoreRender.createCoreRender(gl);
renderToTexture = CoreFBO.createCoreFBO(gl);
renderToTexture.bindFramebuffer();
texture =
CoreTexture2D.createEmptyTexture(
gl, ColorFormat.RGBA, Type.UNSIGNED_BYTE, width, height, ResizeFilter.Linear);
renderToTexture.attachTexture(texture.getTextureId(), 0);
shader = CoreShader.createShaderWithVertexAttributes(gl, "aVertex", "aUV");
shader.vertexShader("de/lessvoid/coregl/plain-texture.vs");
shader.fragmentShader("de/lessvoid/coregl/plain-texture.fs");
shader.link();
shader.activate();
shader.setUniformi("uTexture", 0);
vao = CoreVAO.createCoreVAO(gl);
vao.bind();
vbo = CoreVBO.createCoreVBO(gl, DataType.FLOAT, UsageType.STREAM_DRAW, 4 * 4);
vbo.bind();
vao.enableVertexAttribute(0);
vao.vertexAttribPointer(0, 2, FloatType.FLOAT, 4, 0);
vao.enableVertexAttribute(1);
vao.vertexAttribPointer(1, 2, FloatType.FLOAT, 4, 2);
renderToTexture.bindFramebuffer();
coreRender.clearColor(0.f, 0.f, 0.f, 0.f);
coreRender.clearColorBuffer();
renderToTexture.disableAndResetViewport(width, height);
vao.unbind();
generator = new TextureAtlasGenerator(width, height);
}
private void put(final CoreTexture2D source, final int x, final int y) {
shader.activate();
shader.setUniformMatrix(
"uMvp",
4,
MatrixFactory.createOrtho(0, texture.getWidth(), 0, texture.getHeight()).toBuffer());
vao.bind();
renderToTexture.bindFramebuffer();
final FloatBuffer buffer = vbo.getBuffer();
buffer.put(x);
buffer.put(y);
buffer.put(0.0f);
buffer.put(0.0f);
buffer.put(x);
buffer.put(y + source.getHeight());
buffer.put(0.0f);
buffer.put(1.0f);
buffer.put(x + source.getWidth());
buffer.put(y);
buffer.put(1.0f);
buffer.put(0.0f);
buffer.put(x + source.getWidth());
buffer.put(y + source.getHeight());
buffer.put(1.0f);
buffer.put(1.0f);
buffer.rewind();
vbo.bind();
vbo.send();
coreRender.renderTriangleStrip(4);
vao.unbind();
renderToTexture.disableAndResetViewport(source.getWidth(), source.getHeight());
}