/*

ahbejarano

Renderer class.

*/

package geetransit.minecraft05.engine;

import java.util.*;

import org.joml.Matrix4f;

import static org.lwjgl.opengl.GL30.*;

public abstract class Renderer {

protected Transformation transformation;

public Renderer() {

this.transformation = new Transformation();

}

// create shaders

public abstract void init(Window window) throws Exception;

// render scene

public abstract void render(Window window);

// destroy shaders

public abstract void cleanup();

public Shader createShader(String vertex, String fragment) throws Exception {

Shader shader = new Shader();

shader.createVertexShader(Utils.loadResource(vertex));

shader.createFragmentShader(Utils.loadResource(fragment));

shader.link();

return shader;

}

public Shader create3D(String vertex, String fragment) throws Exception {

Shader shader = this.createShader(vertex, fragment);

shader.createUniform("projectionMatrix");

shader.createUniform("modelViewMatrix");

shader.createUniform("texture_sampler");

shader.createUniform("color");

shader.createUniform("isTextured");

shader.createUniform("isSelected");

return shader;

}

public Shader create2D(String vertex, String fragment) throws Exception {

Shader shader = this.createShader(vertex, fragment);

shader.createUniform("projModelMatrix");

shader.createUniform("texture_sampler");

shader.createUniform("color");

shader.createUniform("isTextured");

return shader;

}

public void render3D(Shader shader, Window window, Camera camera, List<Item> items) {

shader.bind();

glEnable(GL_CULL_FACE);

glCullFace(GL_BACK);

// projection

Matrix4f projectionMatrix = this.transformation.getProjectionMatrix(window, camera);

shader.setUniform("projectionMatrix", projectionMatrix);

// view

Matrix4f viewMatrix = camera.getViewMatrix();

// Draw meshes

shader.setUniform("texture_sampler", 0);

int itemsSize = items.size();

for (int i = 0; i < itemsSize; i++) {

Item item = items.get(i);

Mesh mesh = item.getMesh();

Matrix4f modelViewMatrix = this.transformation.getModelViewMatrix(item, viewMatrix);

shader.setUniform("modelViewMatrix", modelViewMatrix);

shader.setUniform("color", mesh.getColor());

shader.setUniform("isTextured", mesh.isTextured());

shader.setUniform("isSelected", item.isSelected());

mesh.prepare(this.getMeshFromItems(items, i-1, itemsSize));

mesh.render();

mesh.restore(this.getMeshFromItems(items, i+1, itemsSize));

}

glDisable(GL_CULL_FACE);

shader.unbind();

}

// note does NOT call Item.render(Window)

public void render3DMap(Shader shader, Window window, Camera camera, Map<Mesh, List<Item>> map) {

shader.bind();

glEnable(GL_CULL_FACE);

glCullFace(GL_BACK);

// projection

Matrix4f projectionMatrix = this.transformation.getProjectionMatrix(window, camera);

shader.setUniform("projectionMatrix", projectionMatrix);

// view

Matrix4f viewMatrix = camera.getViewMatrix();

// Draw meshes

shader.setUniform("texture_sampler", 0);

for (Map.Entry<Mesh, List<Item>> entry : map.entrySet()) {

Mesh mesh = entry.getKey();

List<Item> items = entry.getValue();

shader.setUniform("color", mesh.getColor());

shader.setUniform("isTextured", mesh.isTextured());

mesh.prepare();

// single : loop through items

for (Item item : items) {

Matrix4f modelViewMatrix = this.transformation.getModelViewMatrix(item, viewMatrix);

shader.setUniform("modelViewMatrix", modelViewMatrix);

shader.setUniform("isSelected", item.isSelected());

mesh.render();

}

mesh.restore();

}

glDisable(GL_CULL_FACE);

shader.unbind();

}

public void render2D(Shader shader, Window window, List<Item> items) {

shader.bind();

// source # https://stackoverflow.com/a/5467636

glDepthMask(false); // disable writes to Z-Buffer

glDisable(GL_DEPTH_TEST); // disable depth-testing

Matrix4f orthoMatrix = this.transformation.getOrthoProjectionMatrix(window);

// Draw meshes

shader.setUniform("texture_sampler", 0);

for (Item item : items) {

Matrix4f projModelMatrix = this.transformation.getOrthoProjModelMatrix(item, orthoMatrix);

shader.setUniform("projModelMatrix", projModelMatrix);

shader.setUniform("color", item.getMesh().getColor());

shader.setUniform("isTextured", item.getMesh().isTextured());

item.render(window);

}

glDepthMask(true);

glEnable(GL_DEPTH_TEST);

shader.unbind();

}

public void renderSkybox(Shader shader, Window window, Camera camera, List<Item> items) {

shader.bind();

// projection

Matrix4f projectionMatrix = this.transformation.getProjectionMatrix(window, camera);

shader.setUniform("projectionMatrix", projectionMatrix);

// view

Matrix4f viewMatrix = camera.getViewMatrix();

// remove translation (different from render3D)

viewMatrix.setTranslation(0, 0, 0);

// Draw meshes

shader.setUniform("texture_sampler", 0);

for (Item item : items) {

Matrix4f modelViewMatrix = this.transformation.getModelViewMatrix(item, viewMatrix);

shader.setUniform("modelViewMatrix", modelViewMatrix);

shader.setUniform("color", item.getMesh().getColor());

shader.setUniform("isTextured", item.getMesh().isTextured());

item.render(window);

}

shader.unbind();

}

public Mesh getMeshFromItems(List<Item> items, int index) { return this.getMeshFromItems(items, index, items.size()); }

public Mesh getMeshFromItems(List<Item> items, int index, int size) {

if (0 <= index && index < size)

return items.get(index).getMesh();

return null;

}

}