Shader.java

package game.graphics;

import static org.lwjgl.opengl.GL20.*;

import java.util.HashMap;
import java.util.Map;

import game.math.Matrix4f;
import game.math.Vector3f;
import game.utils.ShaderUtils;


public class Shader {
	
	public static final int VERTEX_ATTRIB = 0;
	public static final int TCOORD_ATTRIB = 1;
	
	public static Shader SMOOTH_FLOOR;
	
	private boolean enabled = false;
	
	private final int ID;
	private Map<String, Integer> locationCache = new HashMap<String, Integer>();
	
	public Shader(String vertex, String fragment) {
		ID = ShaderUtils.load(vertex, fragment);
	}
	
	public static void loadAll() {
		SMOOTH_FLOOR = new Shader("shaders/SmoothFloor.vert", 
								  "shaders/SmoothFloor.frag");
	}
	
	public int getUniform(String name) {
		if (locationCache.containsKey(name)) {
			return locationCache.get(name);
		}
		int result = glGetUniformLocation(ID, name);
		if (result == -1) {
			System.err.println("Could not find uniform variable '" + name + "'!");
		} else {
			locationCache.put(name, result);
		}
		return result;
	}
	
	public void setUniform1i(String name, int value) {
		if (!enabled) {
			enable();
		}
		glUniform1i(getUniform(name), value);
	}
	
	public void setUniform1f(String name, float value) {
		if (!enabled) {
			enable();
		}
		glUniform1f(getUniform(name), value);
	}
	
	public void setUniform2f(String name, float x, float y) {
		if (!enabled) {
			enable();
		}
		glUniform2f(getUniform(name), x, y);
	}
	
	public void setUniform3f(String name, Vector3f vector) {
		if (!enabled) {
			enable();
		}
		glUniform3f(getUniform(name), vector.x, vector.y, vector.z);
	}
	
	public void setUniformMat4f(String name, Matrix4f matrix) {
		if (!enabled) {
			enable();
		}
		glUniformMatrix4fv(getUniform(name), false, matrix.toFloatBuffer());
	}
	
	public void enable() {
		glUseProgram(ID);
		enabled = true;
	}
	
	public void disable() {
		glUseProgram(0);
		enabled = false;
	}
}