package renderer;

import static org.lwjgl.opengl.GL11.GL_DEPTH_TEST;

import static org.lwjgl.opengl.GL11.GL_LEQUAL;

import static org.lwjgl.opengl.GL11.glDepthFunc;

import static org.lwjgl.opengl.GL11.glDepthMask;

import static org.lwjgl.opengl.GL11.glDepthRange;

import static org.lwjgl.opengl.GL11.glEnable;

import static org.lwjgl.opengl.GL15.GL_DYNAMIC_DRAW;

import static org.lwjgl.opengl.GL15.glBindBuffer;

import static org.lwjgl.opengl.GL15.glBufferData;

import static org.lwjgl.opengl.GL15.glGenBuffers;

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

import static org.lwjgl.opengl.GL31.GL_UNIFORM_BUFFER;

import static org.lwjgl.opengl.GL32.GL_DEPTH_CLAMP;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.nio.ByteBuffer;

import java.nio.ByteOrder;

import java.nio.FloatBuffer;

import math.types.Matrix4;

import org.lwjgl.LWJGLException;

import org.lwjgl.opengl.ContextAttribs;

import org.lwjgl.opengl.Display;

import org.lwjgl.opengl.DisplayMode;

import org.lwjgl.opengl.GL11;

import org.lwjgl.opengl.GL12;

import org.lwjgl.opengl.GL13;

import org.lwjgl.opengl.GL15;

import org.lwjgl.opengl.PixelFormat;

import org.lwjgl.util.glu.GLU;

import assets.entities.Player;

import de.matthiasmann.twl.utils.PNGDecoder;

import de.matthiasmann.twl.utils.PNGDecoder.Format;

public class GLUtilityMethods {

/** OpenGL 4.2 */

// private static final int NUM_MIPMAPS = 3;

private static final boolean ENABLE_MIPMAPPING = true;

private GLUtilityMethods() {

};

public static void exitOnGLError(String errorMessage) {

int errorValue = GL11.glGetError();

if (errorValue != GL11.GL_NO_ERROR) {

String errorString = GLU.gluErrorString(errorValue);

System.err.println("ERROR - " + errorMessage + ": " + errorString);

if (Display.isCreated())

Display.destroy();

System.exit(-1);

}

}

public static int setupOpenGL(int width, int height, String windowTitle, float[] backgroundColor, int projectionBlockIndex) {

// Setup an OpenGL context with API version 3.2

try {

PixelFormat pixelFormat = new PixelFormat();

// withForwardCompatible Forces older versions not to work.

// Doesn't work on OS X

ContextAttribs contextAtrributes = new ContextAttribs(3, 2).withForwardCompatible(true).withProfileCore(true);

Display.setDisplayMode(new DisplayMode(width, height));

Display.setTitle(windowTitle);

// Not necessary to create the canvas like this, except on OS X.

// Does not guarantee forward compatibility with new OpenGL

// versions.

Display.create(pixelFormat, contextAtrributes);

GL11.glViewport(0, 0, width, height);

} catch (LWJGLException e) {

e.printStackTrace();

System.exit(-1);

}

// Setup an XNA like background color

// GL11.glClearColor(0.4f, 0.6f, 0.9f, 0f);

GL11.glClearColor(backgroundColor[0], backgroundColor[1], backgroundColor[2], backgroundColor[3]);

// Map the internal OpenGL coordinate system to the entire screen

// GL11.glViewport(0, 0, width, height);

GL11.glEnable(GL11.GL_CULL_FACE);

GL11.glCullFace(GL11.GL_BACK);

GL11.glFrontFace(GL11.GL_CCW);

glEnable(GL_DEPTH_TEST);

glDepthMask(true);

glDepthFunc(GL_LEQUAL);

glDepthRange(0, 1);

glEnable(GL_DEPTH_CLAMP);

int projectionUniformBuffer = glGenBuffers();

glBindBuffer(GL_UNIFORM_BUFFER, projectionUniformBuffer);

glBufferData(GL_UNIFORM_BUFFER, 16 * 4, GL_DYNAMIC_DRAW);

glBindBufferRange(GL_UNIFORM_BUFFER, projectionBlockIndex, projectionUniformBuffer, 0, 16 * 4);

glBindBuffer(GL_UNIFORM_BUFFER, 0);

resized(width, height, projectionUniformBuffer);

exitOnGLError("setupOpenGL");

return projectionUniformBuffer;

}

public static void resized(int width, int height, int projectionUniformBuffer) {

GL11.glViewport(0, 0, width, height);

GL15.glBindBuffer(GL_UNIFORM_BUFFER, projectionUniformBuffer);

GL15.glBufferSubData(GL_UNIFORM_BUFFER, 0, new Matrix4().clearToPerspectiveDeg(45, width, height, 1, 1000).toBuffer());

GL15.glBindBuffer(GL_UNIFORM_BUFFER, 0);

}

public static void destroyOpenGL(Player player) {

player.destroy();

Display.destroy();

}

public static int loadPNGTextureAsPictureAndBind(String filename, int textureUnit) {

ByteBuffer buf = null;

int tWidth = 0;

int tHeight = 0;

try {

// Open the PNG file as an InputStream

InputStream in = new FileInputStream(filename);

// Link the PNG decoder to this stream

PNGDecoder decoder = new PNGDecoder(in);

// Get the width and height of the texture

tWidth = decoder.getWidth();

tHeight = decoder.getHeight();

// Decode the PNG file in a ByteBuffer

buf = ByteBuffer.allocateDirect(4 * decoder.getWidth() * decoder.getHeight());

decoder.decode(buf, decoder.getWidth() * 4, Format.RGBA);

buf.flip();

in.close();

} catch (IOException e) {

e.printStackTrace();

System.exit(-1);

}

// Create a new texture object in memory and bind it

int texId = GL11.glGenTextures();

GL13.glActiveTexture(textureUnit);

GL11.glBindTexture(GL11.GL_TEXTURE_2D, texId);

// All RGB bytes are aligned to each other and each component is 1 byte

GL11.glPixelStorei(GL11.GL_UNPACK_ALIGNMENT, 1);

// Upload the texture data and generate mip maps (for scaling)

GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGBA, tWidth, tHeight, 0, GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, buf);

/** Replace line above with code below for OpenGL 4.2 */

// GL42.glTexStorage2D(GL11.GL_TEXTURE_2D, NUM_MIPMAPS, GL11.GL_RGBA8,

// tWidth, tHeight);

// GL11.glTexSubImage2D(GL11.GL_TEXTURE_2D, 0, 0, 0, tWidth, tHeight,

// GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, buf);

// if (ENABLE_MIPMAPPING) {

// GL30.glGenerateMipmap(GL11.GL_TEXTURE_2D);

// }

// Setup the ST coordinate system

GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, GL11.GL_REPEAT);

GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_T, GL11.GL_REPEAT);

// Setup what to do when the texture has to be scaled

GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_LINEAR);

if (ENABLE_MIPMAPPING) {

GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR_MIPMAP_NEAREST);

} else {

GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR);

}

exitOnGLError("loadPNGTexture");

return texId;

}

public static int loadPNGTextureAsDataAndBind(String filename, int numColorChannels) {

ByteBuffer buf = null;

int tWidth = 0;

int tHeight = 0;

try {

// Open the PNG file as an InputStream

InputStream in = new FileInputStream(filename);

// Link the PNG decoder to this stream

PNGDecoder decoder = new PNGDecoder(in);

// Get the width and height of the texture

tWidth = decoder.getWidth();

tHeight = decoder.getHeight();

// Decode the PNG file in a ByteBuffer

buf = ByteBuffer.allocateDirect(4 * decoder.getWidth() * decoder.getHeight());

decoder.decodeFlipped(buf, decoder.getWidth() * 4, numColorChannels == 3 ? Format.RGB : Format.RGBA);

buf.flip();

in.close();

} catch (IOException e) {

e.printStackTrace();

System.exit(-1);

}

// Create a new texture object in memory and bind it

int texId = GL11.glGenTextures();

// GL13.glActiveTexture(textureUnit);

GL11.glBindTexture(GL11.GL_TEXTURE_2D, texId);

// All RGB bytes are aligned to each other and each component is 1 byte

GL11.glPixelStorei(GL11.GL_UNPACK_ALIGNMENT, 1);

// MAY NOT BE NECESSARY

// Upload the texture data and generate mip maps (for scaling)

GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, numColorChannels == 3 ? GL11.GL_RGB : GL11.GL_RGBA, tWidth, tHeight, 0,

numColorChannels == 3 ? GL11.GL_RGB : GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, buf);

GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL12.GL_TEXTURE_BASE_LEVEL, 0);

GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL12.GL_TEXTURE_MAX_LEVEL, 0);

GL11.glBindTexture(GL11.GL_TEXTURE_2D, texId);

exitOnGLError("loadPNGTexture");

return texId;

}

public static int loadArrayTextureAsDataAndBind(float[][] data) {

int tWidth = data.length;

int tHeight = data.length;

// Change this to

// http://stackoverflow.com/questions/7070576/get-one-dimensionial-array-from-a-mutlidimensional-array-in-java

// Float is four bytes

ByteBuffer buf = ByteBuffer.allocateDirect(tWidth * tHeight * 4);

buf.order(ByteOrder.nativeOrder());

FloatBuffer fBuf = buf.asFloatBuffer();

for (int y = 0; y < tHeight; y++) {

for (int x = 0; x < tWidth; x++) {

fBuf.put(data[x][y]);

}

}

fBuf.flip();

// Create a new texture object in memory and bind it

int texId = GL11.glGenTextures();

GL11.glBindTexture(GL11.GL_TEXTURE_2D, texId);

// All RGB bytes are aligned to each other and each component is 1 byte

// GL11.glPixelStorei(GL11.GL_UNPACK_ALIGNMENT, 1);

// MAY NOT BE NECESSARY

// Upload the texture data and generate mip maps (for scaling)

GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RED, tWidth, tHeight, 0, GL11.GL_RED, GL11.GL_FLOAT, buf);

GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL12.GL_TEXTURE_BASE_LEVEL, 0);

GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL12.GL_TEXTURE_MAX_LEVEL, 0);

GL11.glBindTexture(GL11.GL_TEXTURE_2D, texId);

return texId;

}

public static ByteBuffer loadPNG(String filename, int numColorChannels) {

ByteBuffer buf = null;

int tWidth = 0;

int tHeight = 0;

try {

// Open the PNG file as an InputStream

InputStream in = new FileInputStream(filename);

// Link the PNG decoder to this stream

PNGDecoder decoder = new PNGDecoder(in);

// Get the width and height of the texture

tWidth = decoder.getWidth();

tHeight = decoder.getHeight();

// Decode the PNG file in a ByteBuffer

buf = ByteBuffer.allocateDirect(4 * decoder.getWidth() * decoder.getHeight());

decoder.decodeFlipped(buf, decoder.getWidth() * 4, numColorChannels == 3 ? Format.RGB : Format.RGBA);

buf.flip();

in.close();

} catch (IOException e) {

e.printStackTrace();

System.exit(-1);

}

return buf;

}

public static int bindBufferAs2DTexture(FloatBuffer buf, int dataType, int width, int height) {

int texId = GL11.glGenTextures();

// GL33.glClampColor(GL33.GL_CLAMP_READ_COLOR, GL_FALSE);

// glClampColor(GL_CLAMP_VERTEX_COLOR, GL_FALSE);

// glClampColor(GL_CLAMP_FRAGMENT_COLOR, GL_FALSE);

GL11.glBindTexture(GL11.GL_TEXTURE_2D, texId);

GL11.glPixelStorei(GL11.GL_UNPACK_ALIGNMENT, 1);

GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, dataType, width, height, 0, dataType, GL11.GL_FLOAT, buf);

GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL12.GL_TEXTURE_BASE_LEVEL, 0);

GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL12.GL_TEXTURE_MAX_LEVEL, 0);

GL11.glBindTexture(GL11.GL_TEXTURE_2D, texId);

return texId;

}

public static int bindBufferAs1DTexture(FloatBuffer buf, int dataType, int size) {

int texId = GL11.glGenTextures();

GL11.glBindTexture(GL11.GL_TEXTURE_1D, texId);

GL11.glPixelStorei(GL11.GL_UNPACK_ALIGNMENT, 1);

GL11.glTexImage1D(GL11.GL_TEXTURE_1D, 0, dataType, size, 0, dataType, GL11.GL_FLOAT, buf);

GL11.glTexParameteri(GL11.GL_TEXTURE_1D, GL12.GL_TEXTURE_BASE_LEVEL, 0);

GL11.glTexParameteri(GL11.GL_TEXTURE_1D, GL12.GL_TEXTURE_MAX_LEVEL, 0);

GL11.glBindTexture(GL11.GL_TEXTURE_1D, texId);

return texId;

}

}