Java - Use the vertex buffer object (vbo) LWJGL - java

OK, I have the following code, i am trying to convert this code into the vertex buffer object render way. but it doesn't seem to work..
So here is the code:
package com.game.base;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengl.GL15.*;
import static org.lwjgl.util.glu.GLU.gluPerspective;
import java.nio.FloatBuffer;
import java.util.Random;
import org.lwjgl.BufferUtils;
import org.lwjgl.input.Keyboard;
import com.game.display.graphics.Entity;
public class Game {
float speed = 0.0f;
float speedChange = 0.000001f;
int stars = 20000;
int starsDistance = 4000;
float starSize = 2.0f;
int vertices = 3;
int vertex_size = 3; // X, Y, Z,
int color_size = 3; // R, G, B,
Entity[] points;
Random random = new Random();
public Game() {
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective((float) 60, (float) (MainClass.WIDTH / MainClass.HEIGHT), 0.001f, 100);
glMatrixMode(GL_MODELVIEW);
glEnable(GL_DEPTH_TEST);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
points = new Entity[stars];
for (int i = 0; i < points.length; i++) {
points[i] = new Entity((random.nextFloat() - 0.5f) * 100f, (random.nextFloat() - 0.5f) * 100f, random.nextInt(starsDistance) - starsDistance);
}
}
public void render() {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glTranslatef(0, 0, speed);
glPointSize(2.0f);
glBegin(GL_POINTS);
for (Entity p : points) {
glVertex3f(p.x, p.y, p.z);
}
glEnd();
}
public void update() {
}
public void dispose() {
}
public void input() {
if (Keyboard.isKeyDown(Keyboard.KEY_UP)) {
speed += speed < 0 ? speedChange * 5 : speedChange;
}
if (Keyboard.isKeyDown(Keyboard.KEY_DOWN)) {
speed -= speed > 0 ? speedChange * 5 : speedChange;
}
if (Keyboard.isKeyDown(Keyboard.KEY_SPACE)) {
speed = 0f;
}
if (Keyboard.isKeyDown(Keyboard.KEY_C)) {
speed = 0;
glLoadIdentity();
}
if (Keyboard.isKeyDown(Keyboard.KEY_ESCAPE)) {
MainClass.stop();
}
}
}
Any ideas how to convert this into VBO (Vertex Buffer Object) ?
Can someone convert this into VBO and show me how?
Thanks in Advance,
And I accept fast :)

Related

java - LWJGL OBJ File Loader not working correctly

I've been trying to load an obj. file into my LWJGL application. I have only the bare bones to get something to appear. My obj. is loading and displaying but its contorted/distorted. I've tried it several ways and still not luck. This is the image I get.
Resulting render of code
Main.java
package Model;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.util.glu.GLU.*;
import org.lwjgl.LWJGLException;
import org.lwjgl.input.Keyboard;
import org.lwjgl.input.Mouse;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.util.vector.Vector3f;
public class Main {
private Model m;
private Vector3f location, rotation;
public static void main(String[] args) {
new Main().run();
}
private void run() {
try {
Display.setDisplayMode(new DisplayMode(1200, 800));
Display.setTitle("3D Game");
Display.create();
} catch (LWJGLException e) {
e.printStackTrace();
Display.destroy();
System.exit(1);
}
location = new Vector3f(0.0f, 0.0f, 0.0f);
rotation = new Vector3f(0.0f, 0.0f, 0.0f);
try {
m = Model.getModel("res/monkey.obj");
} catch (Exception e){
e.printStackTrace();
}
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(30f, (float) (1200/800), 0.3f, 100);
glMatrixMode(GL_MODELVIEW);
glEnable(GL_DEPTH_TEST);
while(!Display.isCloseRequested()){
input();
render();
Display.update();
Display.sync(60);
}
Display.destroy();
System.exit(0);
}
private void input() {
boolean up = Keyboard.isKeyDown(Keyboard.KEY_W);
boolean down = Keyboard.isKeyDown(Keyboard.KEY_S);
boolean left = Keyboard.isKeyDown(Keyboard.KEY_A);
boolean right = Keyboard.isKeyDown(Keyboard.KEY_D);
boolean flyUp = Keyboard.isKeyDown(Keyboard.KEY_E);
boolean flyDown = Keyboard.isKeyDown(Keyboard.KEY_Q);
boolean speedUp = Keyboard.isKeyDown(Keyboard.KEY_LSHIFT);
boolean slowDown = Keyboard.isKeyDown(Keyboard.KEY_LCONTROL);
float walkspeed = 0.15f;
float mx = Mouse.getDX();
float my = Mouse.getDY();
mx *= 0.15f;
my *= 0.15f;
if (Mouse.isButtonDown(0)){
rotation.y += mx;
if (rotation.y > 360){
rotation.y -= 360;
}
rotation.y += my;
if (rotation.x > 85){
rotation.x = 85;
}
if (rotation.x < -85){
rotation.x = -85;
}
}
if(speedUp && !slowDown){
walkspeed = 0.25f;
}
if(slowDown && !speedUp){
walkspeed = 0.15f;
}
if(up && !down){
float cz = (float) (walkspeed * 2 * Math.cos(Math.toRadians(rotation.y)));
float cx = (float) (walkspeed * Math.sin(Math.toRadians(rotation.y)));
location.z += cz;
location.x -= cx;
}
if(down && !up){
float cz = (float) (walkspeed * 2 * Math.cos(Math.toRadians(rotation.y)));
float cx = (float) (walkspeed * Math.sin(Math.toRadians(rotation.y)));
location.z -= cz;
location.x += cx;
}
if(right && !left){
float cz = (float) (walkspeed * 2 * Math.cos(Math.toRadians(rotation.y)) + 90);
float cx = (float) (walkspeed * Math.sin(Math.toRadians(rotation.y)));
location.z += cz;
location.x -= cx;
}
if(left && !right){
float cz = (float) (walkspeed * 2 * Math.cos(Math.toRadians(rotation.y)) + 90);
float cx = (float) (walkspeed * Math.sin(Math.toRadians(rotation.y)));
location.z -= cz;
location.x += cx;
}
if(flyUp && !flyDown){
location.y -= walkspeed;
}
if(flyDown && !flyUp){
location.y += walkspeed;
}
}
private void render() {
glPushMatrix();
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glRotatef(rotation.x, 1f, 0f, 0f);
glRotatef(rotation.y, 0f, 1f, 0f);
glRotatef(rotation.z, 0f, 0f, 1f);
glTranslatef(location.x, location.y, location.z);
m.render();
glPopMatrix();
}
}
Model.java
package Model;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.lwjgl.util.vector.Vector3f;
import static org.lwjgl.opengl.GL11.*;
public class Model {
public List<Vector3f> verts;
public List<Vector3f> norms;
public List<Face> faces;
public static Model getModel(String s) throws IOException{
return new Model(s);
}
private Model(String path) throws IOException{
verts = new ArrayList<Vector3f>();
norms = new ArrayList<Vector3f>();
faces = new ArrayList<Face>();
new ModelLoader(this, path);
}
public void render(){
// glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
glBegin(GL_TRIANGLES);
for (Face f : faces){
Vector3f v1 = verts.get((int) f.verts.x -1);
Vector3f n1 = verts.get((int) f.norms.x -1);
Vector3f v2 = verts.get((int) f.verts.y -1);
Vector3f n2 = verts.get((int) f.norms.y -1);
Vector3f v3 = verts.get((int) f.verts.z -1);
Vector3f n3 = verts.get((int) f.norms.z -1);
glNormal3f(n1.x, n1.y, n1.z);
glVertex3f(v1.x, v1.y, v1.z);
glNormal3f(n2.x, n2.y, n2.z);
glVertex3f(v2.x, v2.y, v2.z);
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(v2.x, v3.y, v3.z);
}
glEnd();
}
}
ModelLoader.java
package Model;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import org.lwjgl.util.vector.Vector3f;
public class ModelLoader {
public ModelLoader(Model m, String path) throws IOException {
BufferedReader read = new BufferedReader(new FileReader(new File(path)));
String line;
while((line = read.readLine()) != null) {
if (line.startsWith("v ")){
float x = Float.valueOf(line.split(" ")[1]);
float y = Float.valueOf(line.split(" ")[2]);
float z = Float.valueOf(line.split(" ")[3]);
Vector3f v = new Vector3f(x, y, z);
m.verts.add(v);
} else if (line.startsWith("vn ")) {
float x = Float.valueOf(line.split(" ")[1]);
float y = Float.valueOf(line.split(" ")[2]);
float z = Float.valueOf(line.split(" ")[3]);
Vector3f v = new Vector3f(x, y, z);
m.norms.add(v);
} else if (line.startsWith("f ")) {
float x1 = Float.valueOf(line.split(" ")[1].split("/")[0]);
float y1 = Float.valueOf(line.split(" ")[2].split("/")[0]);
float z1 = Float.valueOf(line.split(" ")[3].split("/")[0]);
float x2 = Float.valueOf(line.split(" ")[1].split("/")[2]);
float y2 = Float.valueOf(line.split(" ")[2].split("/")[2]);
float z2 = Float.valueOf(line.split(" ")[3].split("/")[2]);
Face f = new Face(new Vector3f(x2, y2, z2), new Vector3f(x1, y1, z1));
m.faces.add(f);
}
}
read.close();
}
}
Face.java
package Model;
import org.lwjgl.util.vector.Vector3f;
public class Face {
public Vector3f norms, verts;
public Face(Vector3f n, Vector3f v){
this.norms = n;
this.verts = v;
}
}
You are in fact very close. If you look at the image of the monkey head,from blender I believe, it has most of the triangles being drawn. Half of the triangles are rendered. This leads me to believe that there is a problem with the order that indices for some of the faces are made.
Secondly I have another idea. Since this has been exported from blender I would suggest making sure that you exported the monkey head with triangulation selected in the export options. This would ensure triangles to be created and not quads. Possibly you are extracting only the first three indices from the face line ("f ") and this would result in these triangles.
For the first possible fix I would recommend trying to disable face culling to see if it is fixed. If this does fix the model then the problem is withing the order of indices for faces.
Secondly I have just noticed that in your last glVertex3f of the render you have written v2 instead of v3 for the vertices x reference. This most likely is the problem.
Third if these do not work, then try exporting from blender again making sure to triangulate the model.

OpenGL doesn't draw with my own matrix

I am trying to make a 2D game with opengl.I made the the class which draw meshes.And i made my own Matrix4f class.I have experience with 3D opengl.
When i pass my matrix4f to the shader it doesn't draw.But when i remove it from multiplying with the position the triangle appears on the screen.I tried my Matrix4f from my 3D Game Engine but it doesn't work as well.
Matrix4f class
package com.game.main.maths;
import java.nio.FloatBuffer;
import com.game.main.util.Util;
public class Matrix4f {
private float[][] m;
public Matrix4f() {
m = new float[4][4];
initIdentity();
}
public Matrix4f initIdentity() {
for (int x = 0; x < 4; x++)
for (int y = 0; y < 4; y++) {
if (x == y)
m[x][y] = 1.0f;
else
m[x][y] = 0;
}
return this;
}
public Matrix4f translate(float x, float y, float z) {
initIdentity();
m[0][3] = x;
m[1][3] = y;
m[2][3] = z;
return this;
}
public Matrix4f translate(Vector3f pos) {
initIdentity();
m[0][3] = pos.getX();
m[1][3] = pos.getY();
m[2][3] = pos.getZ();
return this;
}
public Matrix4f rotate(float angle) {
initIdentity();
float rad = (float) Math.toRadians(angle);
float cos = (float) Math.cos(rad);
float sin = (float) Math.sin(rad);
m[0][0] = cos;
m[1][0] = sin;
m[0][1] = -sin;
m[1][1] = cos;
return this;
}
public Matrix4f initOrthographic(float left, float right, float bottom,
float top, float near, float far) {
initIdentity();
m[0][0] = 2.0f / (right - left);
m[1][1] = 2.0f / (top - bottom);
m[2][2] = 2.0f / (near - far);
m[0][3] = (left + right) / (left - right);
m[1][3] = (bottom + top) / (bottom - top);
m[2][3] = (near + far) / (far - near);
return this;
}
public Matrix4f mul(Matrix4f matrix) {
Matrix4f result = new Matrix4f();
for (int y = 0; y < 4; y++) {
for (int x = 0; x < 4; x++) {
float sum = 0.0f;
for (int index = 0; index < 4; index++)
sum += m[index][y] * matrix.get(x, index);
result.set(x, y, sum);
}
}
return result;
}
public float[][] getM() {
return m;
}
public float get(int x, int y) {
return m[x][y];
}
public void setM(float[][] m) {
this.m = m;
}
public void set(int x, int y, float value) {
m[x][y] = value;
}
public FloatBuffer toFloatBuffer() {
return Util.createFlippedBufferBuffer(this);
}
}
Shader class function
public void setUniform(String uniformName, Matrix4f matrix){
int uniformLocation = getUniformLocation(uniformName);
glUniformMatrix4(uniformLocation, false, matrix.toFloatBuffer());
}
Util class
package com.game.main.util;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import com.game.main.graphics.Vertex;
import com.game.main.maths.Matrix4f;
public class Util {
public static FloatBuffer createFlippedBuffer(float[] data){
FloatBuffer buffer = ByteBuffer.allocateDirect(data.length * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
buffer.put(data).flip();
return buffer;
}
public static IntBuffer createFlippedBuffer(int[] data){
IntBuffer buffer = ByteBuffer.allocateDirect(data.length * 4).order(ByteOrder.nativeOrder()).asIntBuffer();
buffer.put(data).flip();
return buffer;
}
public static IntBuffer createIntBuffer(int size){
IntBuffer buffer = ByteBuffer.allocateDirect(size * 4).order(ByteOrder.nativeOrder()).asIntBuffer();
return buffer;
}
public static FloatBuffer createFloatBuffer(int size){
FloatBuffer buffer = ByteBuffer.allocateDirect(size * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
return buffer;
}
public static FloatBuffer createFlippedBufferBuffer(Matrix4f matrix){
FloatBuffer buffer = createFloatBuffer(4 * 4);
for(int x = 0; x < 4; x++)
for(int y = 0; y < 4; y++)
buffer.put(matrix.get(x, y));
buffer.flip();
return buffer;
}
public static FloatBuffer createFlippedBuffer(Vertex[] vertecies){
FloatBuffer buffer = createFloatBuffer(vertecies.length * Vertex.SIZE);
for(int i = 0; i < vertecies.length; i++){
buffer.put(vertecies[i].getPos().getX());
buffer.put(vertecies[i].getPos().getY());
buffer.put(vertecies[i].getPos().getZ());
buffer.put(vertecies[i].getTexCoord().getX());
buffer.put(vertecies[i].getTexCoord().getY());
}
buffer.flip();
return buffer;
}
}
Initializing the matrix uniform
Matrix4f matrix = new Matrix4f().initOrthographic(0, 800, 0, 600, -1.0f, 1.0f);
Shader.Object.setUniform("mat", matrix);
Vertex Shader
#version 330
layout(location = 0) in vec3 pos;
uniform mat4 mat;
void main(){
gl_Position = mat * vec4(pos, 1.0f);
}
Mesh class
package com.game.main.graphics;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengl.GL15.*;
import static org.lwjgl.opengl.GL20.*;
import com.game.main.util.Util;
public class Mesh {
private int vbo, ibo, size;
public Mesh(Vertex[] vertecies, int[] indices){
vbo = glGenBuffers();
ibo = glGenBuffers();
size = indices.length;
createMesh(vertecies, indices);
}
private void createMesh(Vertex[] vertecies, int[] indices){
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferData(GL_ARRAY_BUFFER, Util.createFlippedBuffer(vertecies), GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(0, 3, GL_FLOAT, false, 5 * 4, 0);
glVertexAttribPointer(1, 2, GL_FLOAT, false, 5 * 4, 0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, Util.createFlippedBuffer(indices), GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}
public void bind(){
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
}
public void unbind(){
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}
public void drawWithBinding()
{
bind();
glDrawElements(GL_TRIANGLES, size, GL_UNSIGNED_INT, 0);
unbind();
}
public void draw(){
glDrawElements(GL_TRIANGLES, size, GL_UNSIGNED_INT, 0);
}
public void destroy(){
glDeleteBuffers(ibo);
glDeleteBuffers(vbo);
}
}
Vertex class
package com.game.main.graphics;
import com.game.main.maths.Vector2f;
import com.game.main.maths.Vector3f;
public class Vertex {
private Vector3f pos = new Vector3f();
private Vector2f texCoord = new Vector2f();
public static final int SIZE = 5;
public Vertex(Vector3f pos){
this(pos, new Vector2f());
}
public Vertex(Vector3f pos, Vector2f texCoord){
this.pos = pos;
this.texCoord = texCoord;
}
public Vector3f getPos() {
return pos;
}
public void setPos(Vector3f pos) {
this.pos = pos;
}
public Vector2f getTexCoord() {
return texCoord;
}
public void setTexCoord(Vector2f texCoord) {
this.texCoord = texCoord;
}
}
transpose code
public Matrix4f transpose() {
float m00 = get(0, 0);
float m01 = get(1, 0);
float m02 = get(2, 0);
float m03 = get(3, 0);
float m10 = get(0, 1);
float m11 = get(1, 1);
float m12 = get(2, 1);
float m13 = get(3, 1);
float m20 = get(0, 2);
float m21 = get(1, 2);
float m22 = get(2, 2);
float m23 = get(3, 2);
float m30 = get(0, 3);
float m31 = get(1, 3);
float m32 = get(2, 3);
float m33 = get(3, 3);
set(0, 0, m00);
set(0, 1, m01);
set(0, 2, m02);
set(0, 3, m03);
set(1, 0, m10);
set(1, 1, m11);
set(1, 2, m12);
set(1, 3, m13);
set(2, 0, m20);
set(2, 1, m21);
set(2, 2, m22);
set(2, 3, m23);
set(3, 0, m30);
set(3, 1, m31);
set(3, 2, m32);
set(3, 3, m33);
return this;
}
Game class
package com.game.main;
import static org.lwjgl.opengl.GL11.*;
import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import com.game.main.graphics.Mesh;
import com.game.main.graphics.Shader;
import com.game.main.graphics.Vertex;
import com.game.main.maths.Matrix4f;
import com.game.main.maths.Vector3f;
public class Game{
private boolean running = false;
private Mesh mesh;
public Game(int width, int height){
try {
Display.setDisplayMode(new DisplayMode(800, 600));
Display.setTitle("2D Game");
Display.create();
} catch (LWJGLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Matrix4f matrix = new Matrix4f().initOrthographic(-1, 1, -1, 1, -1.0f, 1.0f);
Shader.Object.setUniform("mat", matrix);
Vertex[] vertecies = new Vertex[]{
new Vertex(new Vector3f(0.5f, 0.5f, 0)),
new Vertex(new Vector3f(0.5f, 0,0)),
new Vertex(new Vector3f(0, 0.5f,0)),
new Vertex(new Vector3f(0.5f, 0,0))
};
/*float[] vertecies = new float[]{
-10f, -10f * 9.0f / 16.0f, 1,
-10f, 10f * 9.0f / 16.0f,1,
0, 10f * 9.0f / 1.0f,1,
0, -10f * 9.0f / 6.0f,1
};*/
int[] ind = new int[]{
0, 1, 2,
2, 3, 0
};
mesh = new Mesh(vertecies, ind);
}
private void init(){
glEnable(GL_DEPTH_TEST);
}
public void start(){
if(running)
return;
running = true;
gameLoop();
}
public void stop(){
if(!running)
return;
running = false;
}
private void gameLoop(){
init();
long timer = System.currentTimeMillis();
long lastTime = System.nanoTime();
double delta = 0;
int frames = 0, updates = 0;
while(running){
long now = System.nanoTime();
delta += (now - lastTime) / (1000000000.0 / 60.0);
lastTime = now;
while(delta >= 1){
if(Display.isCloseRequested())
stop();
update();
updates++;
delta--;
}
render();
frames++;
if(System.currentTimeMillis() - timer >= 1000){
timer += 1000;
Display.setTitle("Frames: "+frames+" Updates: "+updates);
frames = updates = 0;
}
}
destroy();
}
private void update(){
}
private void render(){
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
Shader.Object.bind();
mesh.drawWithBinding();
Shader.Object.unbind();
Display.update();
}
private void destroy(){
mesh.destroy();
Display.destroy();
}
}
It seems the problem is in setting the matrix uniform. OpenGL is a state machine and doesn't remember uniform values. More importantly, glUniformMatrix4 must be called while the shader is in use.
Currently, the matrix is set only at initialization (in the Game constructor), when it needs to be in render().
Shader.Object.bind(); //glUseProgram(programHandle)
Shader.Object.setUniform(...) //glUniformMatrix4
mesh.drawWithBinding(); //glDrawElements
Shader.Object.unbind(); //glUseProgram(0), but not necessary unless you want fixed function rendering
With mat not being set it'd probably be a zero matrix that was stopping things from drawing.
In addition to the above, there are two other potential issues:
Take a look in the bottom left of your screen and see if that pixel is on. I suspect everything's working, just really small. If the following works:
gl_Position = vec4(pos, 1.0f);
which is essentially a multiply by the identity matrix and nearly ortho(-1,1,-1,1,-1,1) (except the ortho call gives mat[2][2]=-1), then I'm guessing your mesh is around the size of a unit cube.
Introducing mat = initOrthographic(0, 800, 0, 600, -1.0f, 1.0f) looks like it's set up for a scene where vertices are given in pixels. The origin will be bottom left and if the mesh fits in a unit cube will draw to at most one pixel.
See #Jerem's answer about row/column major matrices.
It looks like your matrix is row major. You need to transpose it before sending it to the shader.
Note that there is a boolean parameter called transpose in glUniformMatrix4f but you can't use it in opengl es - the doc says it has to be false - you have to transpose it yourself.

Drawing an isosceles triangle/arrow with two points

I have been trying to figure this one out for some time now, I am making a program that uses a triangle as an arrow and been trying to figure out how to make an arrow with two points, meaning that that the first point would be at the midpoint of the base of the triangle, while the second point would be at the tip facing the direction away from the first point.
This crude paint drawing should help figure out what I am talking about
http://i.stack.imgur.com/f3ktz.png (Would put direct images but don't have enough rep)
Now, I went through and tried figuring out how to calculate those other two endpoints of the triangle so I could make the polygon, but I am not doing it correctly because I am getting a triangle that isn't isosceles and the endpoints don't create a line perpendicular to the original line.
What I am currently getting (With some drawing over it to show the points)
http://i.stack.imgur.com/dljsn.png
My current code
public class Triangle extends Shape{
private boolean assigned = false;
private int[] x;
private int[] y;
public Triangle(Point startPoint, Point endPoint){
this.startPoint = startPoint;
this.endPoint = endPoint;
}
#Override
public void draw(Graphics g) {
g.setColor(Color.white);
if(!assigned) {
x = new int[3];
y = new int[3];
double distance = startPoint.distance(endPoint);
double halfDistance = distance/2;
double angle = getAngle(startPoint,endPoint)- Math.PI/2.0;
x[0] = (int)endPoint.getX();
y[0] = (int)endPoint.getY();
x[1] = (int)((Math.sin(angle)*halfDistance) + startPoint.getX());
y[1] = (int)((Math.cos(angle)*halfDistance) + startPoint.getY());
x[2] = (int)(startPoint.getX() - (Math.sin(angle)*halfDistance));
y[2] = (int)(startPoint.getY() - (Math.cos(angle)*halfDistance));
assigned = true;
if(endPoint.distance(x[1],y[1]) == (Math.sqrt(5)*halfDistance))
System.out.println("DEBUG: Confirm Correct 1");
if(endPoint.distance(x[1],y[1]) == endPoint.distance(x[2],y[2]))
System.out.println("DEBUG: Confirm Correct 2");
}
g.fillPolygon(x,y,3);
g.setColor(Color.blue);
}
private double getAngle(Point pointOne, Point pointTwo){
double angle = Math.atan2(pointTwo.getY()- pointOne.getY(),pointTwo.getX()-pointOne.getX());
while(angle < 0){
angle += (2.0*Math.PI);
}
return angle;
}
}
I have working at this for hours and can't seem to figure it out, someone please help.
So, I ended up replacing double angle = getAngle(startPoint,endPoint)- Math.PI/2.0; with something more like double angle = -Math.atan2(endPoint.y - startPoint.y, endPoint.x - startPoint.x);
I wrote this little test program, which allows you to move to points around a circle and which generates the resulting triangle...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Point;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
TestPane tp = new TestPane();
JPanel control = new JPanel(new BorderLayout());
control.add(tp);
final JSlider startAngel = new JSlider(0, 359);
final JSlider endAngel = new JSlider(0, 359);
JPanel sliders = new JPanel(new GridLayout(1, 2));
sliders.add(startAngel);
sliders.add(endAngel);
startAngel.addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent e) {
tp.setStartAngle(startAngel.getValue());
}
});
endAngel.addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent e) {
tp.setEndAngle(endAngel.getValue());
}
});
startAngel.setValue(0);
endAngel.setValue(180);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(control);
frame.add(sliders, BorderLayout.SOUTH);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private Point startPoint, endPoint;
private float startAngle = 0;
private float endAngle = 180;
public TestPane() {
}
#Override
public void invalidate() {
super.invalidate();
recalculate();
}
protected void recalculate() {
int dim = Math.min(getWidth(), getHeight());
dim -= 50;
float radius = dim / 2f;
startPoint = getPointOnCircle(startAngle, radius);
endPoint = getPointOnCircle(endAngle, radius);
repaint();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
protected Point getPointOnCircle(float degress, float radius) {
int x = Math.round(getWidth() / 2);
int y = Math.round(getHeight() / 2);
double rads = Math.toRadians(degress - 90); // 0 becomes the top
// Calculate the outter point of the line
int xPosy = Math.round((float) (x + Math.cos(rads) * radius));
int yPosy = Math.round((float) (y + Math.sin(rads) * radius));
return new Point(xPosy, yPosy);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
int[] x = new int[3];
int[] y = new int[3];
double distance = startPoint.distance(endPoint);
double halfDistance = distance / 2;
double angle = -Math.atan2(endPoint.y - startPoint.y, endPoint.x - startPoint.x);
System.out.println(angle);
x[0] = (int) endPoint.getX();
y[0] = (int) endPoint.getY();
x[1] = (int) ((Math.sin(angle) * halfDistance) + startPoint.getX());
y[1] = (int) ((Math.cos(angle) * halfDistance) + startPoint.getY());
x[2] = (int) (startPoint.getX() - (Math.sin(angle) * halfDistance));
y[2] = (int) (startPoint.getY() - (Math.cos(angle) * halfDistance));
g2d.setColor(Color.RED);
g2d.fillPolygon(x, y, 3);
g2d.setColor(Color.BLUE);
g2d.fillOval(startPoint.x - 5, startPoint.y - 5, 10, 10);
g2d.setColor(Color.GREEN);
g2d.fillOval(endPoint.x - 5, endPoint.y - 5, 10, 10);
g2d.dispose();
}
public void setStartAngle(float value) {
startAngle = value;
recalculate();
}
public void setEndAngle(float value) {
endAngle = value;
recalculate();
}
}
}
If that still gives you some weird results, apart from sharing some test data, I might consider using something like Math.atan2(Math.abs(endPoint.y - startPoint.y), Math.abs(endPoint.x - startPoint.x)) or simular
You don't need to calculate angles at all.
double startX = 40;
double startY = 120;
double endX = 110;
double endY = 15;
double deltaX = ( startY - endY ) / 2;
double deltaY = ( endX - startX ) / 2;
double[] polygonX = new double[3];
double[] polygonY = new double[3];
polygonX[0] = endX;
polygonY[0] = endY;
polygonX[1] = startX - deltaX;
polygonY[1] = startY - deltaY;
polygonX[2] = startX + deltaX;
polygonY[2] = startY + deltaY;
The drawing is VERY bad :D, but the point is that:
cos(ang) = 'distance' / ( startY - endY )
and
cod(ang) = ('distance'/2) / deltaX
so
deltaX = ( startY - endY ) / 2
The same aplies to deltaY = ( endX - startX ) / 2
So the other 2 point of the triangle, will be the startPoint minus and plus those deltas.

Calculate x y of Point after increasing distance

I am trying to get the x and y value of a point after increasing the distance r. Perhaps there is a better way of calculate the angle phi too, so that I don't need to check in which quadrant the point is. The 0-point is at the half of the width and height of the window. Here is my attempt:
package test;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Point;
public final class Laser extends java.applet.Applet implements Runnable{
private static final long serialVersionUID = -7566644836595581327L;
Thread runner;
int width = 800;
int height = 600;
Point point = new Point(405,100);
Point point1 = new Point(405,100);
public void calc(){
int x = getWidth()/2;
int y = getHeight()/2;
int px = point.x;
int py = point.y;
int px1 = point1.x;
int py1 = point1.y;
double r = 0;
double phi = 0;
// Point is in:
// Quadrant 1
if(px > x && py < y){
r = Math.hypot(px1-x, y-py1);
phi = Math.acos((px1-x)/r)*(180/Math.PI);
}/*
// Quadrant 2
else if(px < x && py < y){
r = Math.hypot(x-px, y-py);
phi = Math.acos((px-x)/r)*(180/Math.PI);
}
// Quadrant 3
else if(px < x && py > y){
r = Math.hypot(x-px, py-y);
phi = Math.acos((px-x)/r)*(180/Math.PI)+180;
}
// Quadrant 4
else if(px > x && py > y){
r = Math.hypot(px-x, py-y);
phi = Math.acos((px-x)/r)*(180/Math.PI)+180;
}*/
r += 1;
point1.x = (int) (r*Math.cos(phi));
point1.y = (int) (r*Math.sin(phi));
System.out.println(r+";"+point1.x+";"+point1.y);
}
public void paint(Graphics g) {
g.setColor(Color.ORANGE);
calc();
g.drawLine(point.x, point.y, point1.x, point1.y);
int h = getHeight();
int w = getWidth();
g.setColor(Color.GREEN);
g.drawLine(0, h/2, w, h/2);
g.drawLine(w/2, 0, w/2, h);
}
/*
public void initPoints(){
for(int i = 0; i < pointsStart.length; i++){
int x = (int)(Math.random()*getWidth());
int y = (int)(Math.random()*getHeight());
pointsStart[i] = pointsEnd[i] = new Point(x,y);
}
}
*/
public void start() {
if (runner == null) {
runner = new Thread(this);
setBackground(Color.black);
setSize(width, height);
//initPoints();
runner.start();
}
}
#SuppressWarnings("deprecation")
public void stop() {
if (runner != null) {
runner.stop();
runner = null;
}
}
public void run() {
while (true) {
repaint();
try { Thread.sleep(700); }
catch (InterruptedException e) { }
}
}
public void update(Graphics g) {
paint(g);
}
}
You are changing (x,y) to be r from some other point, when it had previously been some distance r' from that point, correct? So why not avoid the trigonometry, and just scale each of the components from that point by r/r'?
Edit: ok, iterate over the pixels along whichever component (x or y) is longer (let's assume it's y); for each xi in (0..x), yi = xi*(y/x), and you plot (xi,yi).
Keep it simple! And use double variables for such computations, I changed it for you.
package test;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.geom.Point2D;
public final class Laser extends java.applet.Applet implements Runnable {
private static final long serialVersionUID = -7566644836595581327L;
Thread runner;
int width = 800;
int height = 600;
Point2D.Double point = new Point2D.Double(400, 100);
Point2D.Double point1 = new Point2D.Double(405, 102);
public void calc() {
double px = point.x;
double py = point.y;
double px1 = point1.x;
double py1 = point1.y;
double dx = px1 - px;
double dy = py1 - py;
double len = Math.hypot(dx, dy);
double newlen = len+2;
double coeff = Math.abs((newlen-len)/len);
point1.x += dx * coeff;
point1.y += dy * coeff;
System.out.println(len+";"+point1.x+";"+point1.y);
}
public void paint(Graphics g) {
g.setColor(Color.ORANGE);
calc();
g.drawLine((int)point.x, (int)point.y, (int)point1.x, (int)point1.y);
int h = getHeight();
int w = getWidth();
g.setColor(Color.GREEN);
g.drawLine(0, h / 2, w, h / 2);
g.drawLine(w / 2, 0, w / 2, h);
}
/*
* public void initPoints(){
*
* for(double i = 0; i < pointsStart.length; i++){ double x =
* (double)(Math.random()*getWidth()); double y =
* (double)(Math.random()*getHeight()); pointsStart[i] = pointsEnd[i] = new
* Point(x,y); }
*
* }
*/
public void start() {
if (runner == null) {
runner = new Thread(this);
setBackground(Color.black);
setSize(width, height);
// initPoints();
runner.start();
}
}
#SuppressWarnings("deprecation")
public void stop() {
if (runner != null) {
runner.stop();
runner = null;
}
}
public void run() {
while (true) {
repaint();
try {
Thread.sleep(700);
}
catch (InterruptedException e) {
}
}
}
public void update(Graphics g) {
paint(g);
}
}

java.io.IOException Difficulty when adding "player" texture into screen

I get this strange error from loading "Player.png" file from the Player Class.
I understand that my organization of the code is very sloppy and the methods I use are terrible. half of the code is borrowed from tutorials.
What 2 classes are supposed to do is create a screen with green colored tiles filling up the screen with a "player" sprite that can move right, left, up, and down with the W,A,S,D keys.
error:
java.io.IOException: Attempt to allocate a texture to big for the current hardware
at org.newdawn.slick.opengl.InternalTextureLoader.getTexture(InternalTextureLoader.java:293)
at org.newdawn.slick.opengl.InternalTextureLoader.getTexture(InternalTextureLoader.java:231)
at
org.newdawn.slick.opengl.InternalTextureLoader.getTexture(InternalTextureLoader.java:184)
at org.newdawn.slick.opengl.TextureLoader.getTexture(TextureLoader.java:64)
at org.newdawn.slick.opengl.TextureLoader.getTexture(TextureLoader.java:24)
at test.PlayerClass.render(PlayerClass.java:69)
at test.Main.render(Main.java:110)
at test.Main.run(Main.java:82)
at test.Main.main(Main.java:27)
Main Class
public class Main{
private static boolean running = true;
public static final int WIDTH = 1024;
public static final int HEIGHT = 768;
private static Texture tile;
static PlayerClass playerClass = new PlayerClass(100, 100, 32, 32);
public static void main(String[] args){
Main main = new Main();
main.run();
}
//Initialize Method
public static void init(int width, int height ) throws LWJGLException
{
DisplayMode[] m = Display.getAvailableDisplayModes();
for(DisplayMode mode : m)
{
if(mode.getWidth() == 1024 && mode.getHeight() == 768 && mode.getBitsPerPixel() == 32)
{
Display.setDisplayMode(mode);
}
}
Display.setTitle("Game");
Display.setVSyncEnabled(true);
Display.sync(100);
Display.create();
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GL11.glOrtho(0, Display.getDisplayMode().getWidth(), Display.getDisplayMode().getHeight(), 0, -1, 1 );
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glLoadIdentity();
GL11.glEnable(GL11.GL_ALPHA_TEST);
GL11.glAlphaFunc(GL11.GL_GREATER, 0.2f);
GL11.glEnable(GL11.GL_TEXTURE_2D);
try {
tile = TextureLoader.getTexture("PNG", ResourceLoader.getResourceAsStream("RPG/tile.png"));
}
catch (IOException e)
{
e.printStackTrace();
}
}
public void run()
{
try {
init(1024, 768);
} catch (LWJGLException e) {
e.printStackTrace();
}
while(running)
{
Display.update();
drawTiled(WIDTH, HEIGHT);
input();
update();
render();
}
cleanup();
}
public static void input()
{
if(Keyboard.isKeyDown(Keyboard.KEY_ESCAPE))
{
running = false;
}
playerClass.input();
}
public static void update()
{
}
public static void render()
{
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT);
GL11.glLoadIdentity();
try {
playerClass.render();
} catch (IOException e) {
e.printStackTrace();
}
Display.update();
}
public static void cleanup()
{
Display.destroy();
}
public void drawTiled(int screenWidth, int screenHeight) {
Color.white.bind();
tile.bind();
int numberPerRow = screenWidth / tile.getTextureWidth();
int numberOfRows = screenHeight / tile.getTextureHeight();
GL11.glBegin(GL11.GL_QUADS);
for (int j = 0; j < numberOfRows; j++) {
//System.out.print("{");
for (int i = 0; i < numberPerRow; i++)
{
//top left
GL11.glTexCoord2f(0, 0);
GL11.glVertex2f(tile.getTextureWidth() * i, tile.getTextureHeight() * j);
//top right
GL11.glTexCoord2f(1, 0);
GL11.glVertex2f(tile.getTextureWidth() * (i + 1), tile.getTextureHeight() * j);
//bottom right
GL11.glTexCoord2f(1, 1);
GL11.glVertex2f(tile.getTextureWidth() * (i + 1), tile.getTextureHeight() * (j + 1));
//bottom left
GL11.glTexCoord2f(0, 1);
GL11.glVertex2f(tile.getTextureWidth() * i, tile.getTextureHeight() * (j + 1));
}
}
}
}
Player Class
public class PlayerClass {
private float x, y;
private int w, h;
private Texture player;
private FloatBuffer verts = BufferUtils.createFloatBuffer(2 * 4);
private FloatBuffer tex = BufferUtils.createFloatBuffer(2 * 4);
public PlayerClass(float X, float Y, int W, int H)
{
x = X;
y = Y;
w = W;
h = H;
verts.put(new float[]{
0.0f, 0.0f,
32.0f, 0.0f,
32.0f, 32.0f,
0.0f, 32.0f
});
tex.put(new float[]{
0.0f, 0.0f,
1.0f, 0.0f,
1.0f, 1.0f,
0.0f, 1.0f
});
}
public void input()
{
if(Keyboard.isKeyDown(Keyboard.KEY_W))
{
y -= 10;
}
else if(Keyboard.isKeyDown(Keyboard.KEY_S))
{
y += 10;
}
if(Keyboard.isKeyDown(Keyboard.KEY_A))
{
x -= 10;
}
else if(Keyboard.isKeyDown(Keyboard.KEY_D))
{
x += 10;
}
}
public void render() throws IOException
{
player = TextureLoader.getTexture("PNG", ResourceLoader.getResourceAsStream("RPG/player.png"));
player.bind();
verts.rewind();
tex.rewind();
GL11.glEnableClientState(GL11.GL_VERTEX_ARRAY);
GL11.glEnableClientState(GL11.GL_TEXTURE_COORD_ARRAY);
GL11.glTranslatef(x, y, 0.0f);
GL11.glVertexPointer(2, 0, verts);
GL11.glTexCoordPointer(2, 0, tex);
GL11.glDrawArrays(GL11.GL_QUADS, 0, 4);
GL11.glTranslatef(-x, -y, 0.0f);
GL11.glDisableClientState(GL11.GL_VERTEX_ARRAY);
GL11.glDisableClientState(GL11.GL_TEXTURE_COORD_ARRAY);
}
}
Run this:
System.out.println(GL11.glGetInteger(GL11.GL_MAX_TEXTURE_SIZE));
It'll tell you the max texture size allowed by your Graphics card. Make sure that your graphics card can handle a texture of the size that you are trying to use. According to the error, it can't.
How large is tile.png - the maximum texture size can vary depending your card, and I think, some other factors. Your file is probably outside this dimension.
Cody's answer gives you the way to get the max texture size for your card. If you're writing a game for use by many other people, you'll probably want to integrate that code into your game code in such a way that it loads different resolution textures based on the capabilities of the card it's running on, or simply find a default that works on any card that you want to support, and use that for all installations.
Here's some additional reading that will explain more about this issue, some history about it, and more technical info that you might find useful:
Official OpenGL wiki on 'Texture'
List of maximum texture size by video card (from 2006, but you'll get the idea)
An FAQ of texture mapping

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