before showing my code I want to explain the Situation a littlze bit. I am trying to make a FlappyBird clone just for practice using Lwjgl2. Right now I am able to create a textured Quad which can move ONLY in x and y direction and rotate around all the axis. I was about to set up the projectionMatrix so I can also have 3D movement and the Z axis work.
I followed a tutorial on youtube, doing the exact same things but it somehow does not work for me at all.
When trying to move the Object without using the projectionMatrix, it vanishes at soon as Z > 1 or Z < -1 for some reason, although nothing should happen. As soon as I add the projectionMatrix inside the vertexShader it vanishes for every coordinate I give to be rendered at... it just disappears into the void.
Here is all the relevant code:
Model model = loader.loadToVAO(vertices, textureCoords, indices);
ModelTexture texture = new ModelTexture(loader.loadTexture("Flappy2"));
TexturedModel texturedModel = new TexturedModel(model, texture);
Entity entity = new Entity(texturedModel, new Vector3f(0,0,0),0,0,0,1 );
float y = 0;
float x = 0;
//Main loop which renders stuff
while(!Display.isCloseRequested()) {
while(Keyboard.next()) {
if (Keyboard.getEventKey() == Keyboard.KEY_SPACE) {
if (Keyboard.getEventKeyState()) {
y = 0.1f;
}
}
}
y -= 0.005f;
entity.increasePosition(x, y, 0);
entity.increaseRotation(0, 0,0 );
renderer.prepare();
shader.start();
renderer.render(entity, shader);
shader.stop();
DisplayManager.updateDisplay();
}
shader.cleanUp();
loader.cleanUp();
DisplayManager.closeDisplay();
}
This is the main loop, nothing special.
#version 400 core
in vec3 position;
in vec2 textureCoords;
out vec2 pass_textureCoords;
out vec3 color;
uniform mat4 transformationMatrix;
uniform mat4 projectionMatrix;
void main(void){
gl_Position = projectionMatrix * transformationMatrix * vec4(position,1.0);
pass_textureCoords = textureCoords;
color = vec3(position.x +0.5,0.0,position.y+0.5);
}
That was the vertex Shader.
private void createProjectionMatrix() {
float aspectRatio = (float) Display.getDisplayMode().getWidth() / (float) Display.getDisplayMode().getHeight();
float y_scale = (float)(1f / Math.tan(Math.toRadians(FOV / 2f))) * aspectRatio;
float x_scale = y_scale / aspectRatio;
float frustum_length = FAR_PLANE - NEAR_PLANE;
projectionMatrix = new Matrix4f();
projectionMatrix.m00 = x_scale;
projectionMatrix.m11 = y_scale;
projectionMatrix.m22 = -((FAR_PLANE + NEAR_PLANE) / frustum_length);
projectionMatrix.m23 = -1;
projectionMatrix.m32 = -((2 * NEAR_PLANE * FAR_PLANE) / frustum_length);
projectionMatrix.m33 = 0;
}
Here I set up the projectionMatrix in the Rendering class.
As I said, most of it is copied from a youtube tutorial, as I am new to LWJGL2. So if it works for him why does it not for me ?
I tried copying the entire tutorial code, instead of just typing it myself and it did somehow fix my problem.
I probably had switched variable names somewhere or small errors like that which prevented the projection Matrix from working.
No need to comment anymore :) Ignore this post
I'm using OpenGL with LWJGL and my own very small framework for trivial tasks. I'm following the book OpenGL SuperBible: Comprehensive Tutorial and Reference (6th Edition).
I will list the most important parts of my program:
public class GameController extends Controller {
private Program test1Program;
private int vaoId;
#Override
protected void init() {
glViewport(0, 0, 800, 600);
test1Program = new Program(
new VertexShader("src/shaders/test.vert.glsl").create(),
new ControlShader("src/shaders/test.cont.glsl").create(),
new EvaluationShader("src/shaders/test.eval.glsl").create(),
new FragmentShader("src/shaders/test.frag.glsl").create()
).create();
vaoId = glGenVertexArrays();
glBindVertexArray(vaoId);
}
#Override
protected void draw(double msDelta) {
glClearColor((float)Math.sin(currentTime / 1000f) * 0.5f + 0.5f, (float)Math.cos(currentTime / 1000f) * 0.5f + 0.5f, 0.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
test1Program.use();
glVertexAttrib4f(0, (float)Math.sin(currentTime / 1000f) * 0.5f, (float)Math.cos(currentTime / 1000f) * 0.5f, 0.0f, 0.0f);
glVertexAttrib4f(1, (float)Math.sin(currentTime / 1000f * 2f) * 0.5f + 0.5f, (float)Math.cos(currentTime / 1000f * 2f) * 0.5f + 0.5f, 0.0f, 1.0f);
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
glDrawArrays(GL_TRIANGLES, 0, 3);
}
#Override
protected void shutdown() {
test1Program.delete();
glDeleteVertexArrays(vaoId);
}
public static void main(String[] args) {
Controller controller = new GameController();
controller.start();
}
}
My custom VertexShader, ControlShader, EvaluationShader and FragmentShader are working and if shader code does not compile properly or does not get linked correctly, then an exception will be thrown and I would notice it. So I have verified that those and Program are working correctly.
The error (Exception in thread "main" org.lwjgl.opengl.OpenGLException: Invalid operation (1282)) gets thrown at the glDrawArrays call.
test.vert.glsl:
#version 440 core
layout(location = 0) in vec4 offset;
layout(location = 1) in vec4 color;
out VS_OUT {
vec4 color;
} vs_out;
void main() {
const vec4 vertices[3] = vec4[3](
vec4(0.25, -0.25, 0.5, 1.0),
vec4(-0.25, -0.25, 0.5, 1.0),
vec4(0.25, 0.25, 0.5, 1.0)
);
gl_Position = vertices[gl_VertexID] + offset;
vs_out.color = color;
}
test.cont.glsl:
#version 440 core
layout(vertices = 3) out;
void main() {
if (gl_InvocationID == 0) {
gl_TessLevelInner[0] = 5.0;
gl_TessLevelOuter[0] = 5.0;
gl_TessLevelOuter[1] = 5.0;
gl_TessLevelOuter[2] = 5.0;
}
gl_out[gl_InvocationID].gl_Position = gl_in[gl_InvocationID].gl_Position;
}
test.eval.glsl:
#version 440 core
layout(triangles, equal_spacing, cw) in;
void main() {
gl_Position = (gl_TessCoord.x * gl_in[0].gl_Position + gl_TessCoord.y * gl_in[1].gl_Position + gl_TessCoord.z * gl_in[2].gl_Position);
}
#version 440 core
in VS_OUT {
vec4 color;
} fs_in;
out vec4 color;
void main() {
color = fs_in.color;
}
I have triple checked all my code and crosschecked with the book, but have no clue why it is not working. I would appreciate any help and am around to provide additional information if neccessary.
I found the answer just now:
glDrawArrays(GL_TRIANGLES, 0, 3);
needs to be:
glDrawArrays(GL_PATCHES, 0, 3);
Some more effort from OpenGL to show what was wrong would have been appreciated.
Also nowhere in the book it has been (explicitely) mentioned that I need to use GL_PATCHES, I just figured it out by looking at the source code of the compilable examples from the book.
After a more thorough investigation of your shaders, I suspect part of the problem is that there is no vertex attribute 1 (layout(location = 1) in vec4 color) in your program after all of the stages are linked. It is probably not your entire problem, but as it stands right now your GLSL program will not behave the way you want.
You have to pass the data fed into the vertex shader through the tessellation shader stages to get it into the fragment shader stage - if you do not do this, then the GLSL compiler/linker determines that that vertex attribute is not used when the program executes and does not assign it a location. This behavior applies to uniforms as well.
Have a look at another answer I wrote on SO for an explanation on how to do this.
I've just started learning OpenGL for Android and I'm having a weird problem when drawing a circle. some of its vertices stick to the left and top wall making lines go out from the circle a bit randomly. Every time I restart the app they have a different position.
My DrawScreen class where the circle is drawn:
public class DrawScreen implements GLSurfaceView.Renderer {
Ball ball;
public float mAngle;
private int mProgram;
private int maPositionHandle;
private final String vertexShaderCode =
// This matrix member variable provides a hook to manipulate
// the coordinates of the objects that use this vertex shader
"uniform mat4 uMVPMatrix; \n" +
"attribute vec4 vPosition; \n" +
"void main(){ \n" +
// the matrix must be included as a modifier of gl_Position
" gl_Position = uMVPMatrix * vPosition; \n" +
"} \n";
private final String fragmentShaderCode =
"precision mediump float; \n" +
"void main(){ \n" +
" gl_FragColor = vec4 (0.63671875, 0.76953125, 0.22265625, 1.0); \n" +
"} \n";
private int muMVPMatrixHandle;
private float[] mMVPMatrix = new float[16];
private float[] mVMatrix = new float[16];
private float[] mProjMatrix = new float[16];
public void onSurfaceCreated(GL10 unused, EGLConfig config) {
ball = new Ball();
// Set the background frame color
GLES20.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
Matrix.setLookAtM(mVMatrix, 0, 0, 0, -3, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
ball.initShapes(240, 360, 50);
int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode);
mProgram = GLES20.glCreateProgram(); // create empty OpenGL Program
GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader to program
GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program
GLES20.glLinkProgram(mProgram); // creates OpenGL program executables
// get handle to the vertex shader's vPosition member
maPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
}
public void onDrawFrame(GL10 unused) {
// Redraw background color
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
// Add program to OpenGL environment
GLES20.glUseProgram(mProgram);
// Prepare the circle data
GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false, 0, ball.ballVB);
GLES20.glEnableVertexAttribArray(maPositionHandle);
// Apply a ModelView Projection transformation
Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0);
GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, mMVPMatrix, 0);
// Draw the circle
GLES20.glDrawArrays(GLES20.GL_LINE_LOOP, 0, (int) (ball.getNumSeg() * 3));
}
public void onSurfaceChanged(GL10 unused, int width, int height) {
GLES20.glViewport(0, 0, width, height);
float ratio = (float) width / height;
// this projection matrix is applied to object coodinates
// in the onDrawFrame() method
Matrix.frustumM(mProjMatrix, 0, -ratio, ratio, -1, 1, 3, 7);
muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
Matrix.setLookAtM(mVMatrix, 0, 0, 0, -3, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
}
private int loadShader(int type, String shaderCode){
// create a vertex shader type (GLES20.GL_VERTEX_SHADER)
// or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
int shader = GLES20.glCreateShader(type);
// add the source code to the shader and compile it
GLES20.glShaderSource(shader, shaderCode);
GLES20.glCompileShader(shader);
return shader;
}
}
And my Ball class where the circle is created:
public class Ball {
public FloatBuffer ballVB;
private float cx, cy, r;
float numSegments = 360;
public void initShapes(float tx, float ty, float tr){
cx = (tx / 240.f) - 1.f;
cy = (ty / 360.f) - 1.f;
r = (tr / 240.f);
float ballCoords[] = new float[(int) (numSegments * 3)];
double theta = (2 * 3.1415926 / numSegments);
float c = (float) Math.cos(theta);//precalculate the sine and cosine
float s = (float) Math.sin(theta);
float t;
float x = r;//we start at angle = 0
float y = 0;
for(int i = 0; i < (numSegments * 3); i = i + 3 ) {
ballCoords[i] = (x + cx);
ballCoords[i + 1] = (y + cy);
ballCoords[i + 2] = (0);
//apply the rotation matrix
t = x;
x = c * x - s * y;
y = s * t + c * y;
}
// initialize vertex Buffer for triangle
ByteBuffer vbb = ByteBuffer.allocateDirect(
// (# of coordinate values * 4 bytes per float)
ballCoords.length * 4);
vbb.order(ByteOrder.nativeOrder());// use the device hardware's native byte order
ballVB = vbb.asFloatBuffer(); // create a floating point buffer from the ByteBuffer
ballVB.put(ballCoords); // add the coordinates to the FloatBuffer
ballVB.position(0); // set the buffer to read the first coordinate
}
public float getNumSeg(){
return numSegments;
}
}
I've been scouring the internet for hours but haven't found anything. Hope you guys can help me.
GLES20.glDrawArrays(GLES20.GL_LINE_LOOP, 0, (int) (ball.getNumSeg() * 3));
I'm suspicious of this, are segments referring to individual vertices?
The final argument to glDrawArrays is the number of vertices to draw, not the number of floats. You should probably remove the * 3 multiplier from glDrawArrays.
Your extra lines are probably from drawing garbage data because you're drawing 3 times as many vertices as you've actually allocated.
I was trying to make a billboard using LWJGL and I succeeded partially. The quad appears and does face the camera when I strafe. However, as soon as I rotate the camera on any of the axises the quad also moves along the axises in different manners. Here is the code I use:
/***************************************************************************************************************************************************************************************************
* All rendering happens here...
**************************************************************************************************************************************************************************************************/
private void render() {
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT); // Clear The Screen And The Depth Buffer
GL11.glLoadIdentity(); // Reset The View
//GL11.glLight(GL11.GL_LIGHT1, GL11.GL_POSITION, lightPosition); // Position The Light
GL11.glRotatef(360.0f - yrot, 0, 1.0f, 0);
GL11.glRotatef(lookupdown, 1.0f, 0, 0);
GL11.glTranslatef(-xpos, 0, -zpos);
GL11.glCallList(blocksList);
GL11.glCallList(tilesList);
GL11.glCallList(roofList);
/* Render billboards */
Billboard bb = lvLoader.currentLevel.billboards[0];
GL11.glPushMatrix();
GL11.glRotatef(360.0f - yrot, 0, -1.0f, 0);
GL11.glRotatef(lookupdown, -1.0f, 0, 0);
GL11.glBegin(GL11.GL_QUADS);
GL11.glVertex3f(bb.origin.x + 0.5f, bb.origin.y + 0.5f, bb.origin.z);
GL11.glVertex3f(bb.origin.x - 0.5f, bb.origin.y + 0.5f, bb.origin.z);
GL11.glVertex3f(bb.origin.x - 0.5f, bb.origin.y - 0.5f, bb.origin.z);
GL11.glVertex3f(bb.origin.x + 0.5f, bb.origin.y - 0.5f, bb.origin.z);
GL11.glEnd();
GL11.glPopMatrix();
Here are the functions controlling lookupdown and yrot.
if (Keyboard.isKeyDown(Keyboard.KEY_UP)) { // Is PageUp Being Pressed?
lookupdown -= 1.0f; // Rotate The Secene Downwards
}
if (Keyboard.isKeyDown(Keyboard.KEY_DOWN)) { // Is PageDown Being Pressed?
lookupdown += 1.0f; // Rotate The Scene Upwards
}
if (Keyboard.isKeyDown(Keyboard.KEY_RIGHT))
{
yrot -= 1.5f; // Rotate The Scene To The Left
}
if (Keyboard.isKeyDown(Keyboard.KEY_LEFT))
{
yrot += 1.5f; // Rotate The Scene To The Left
}
if (Keyboard.isKeyDown(Keyboard.KEY_W))
{
adjustXZ((float) Math.sin(yrot * piover180) * 0.05f, (float) Math.cos(yrot * piover180) * 0.05f, false, false);
}
if (Keyboard.isKeyDown(Keyboard.KEY_S))
{
adjustXZ((float) Math.sin(yrot * piover180) * 0.05f, (float) Math.cos(yrot * piover180) * 0.05f, true, true);
}
if (Keyboard.isKeyDown(Keyboard.KEY_D))
{
adjustXZ((float) Math.sin((yrot-90) * piover180) * 0.05f, (float) Math.cos((yrot-90) * piover180) * 0.05f, false, false);
}
if (Keyboard.isKeyDown(Keyboard.KEY_A))
{
adjustXZ((float) Math.sin((yrot+90) * piover180) * 0.05f, (float) Math.cos((yrot+90) * piover180) * 0.05f, false, false);
}
private void adjustXZ(float x, float z, boolean xAdd, boolean zAdd)
{
if (collisionCheck(x, z, xAdd, zAdd))
return;
if (xAdd)
xpos += x;
else if (!xAdd)
xpos -= x;
if (zAdd)
zpos += z;
else if (!zAdd)
zpos -= z;
}
I'm not familiar with LWJGL so I'm not 100% sure what it expects, but based on my experience with other 3D API's it sounds very much like you've got your matrix transforms in the wrong order.
Try changing your code as follows:
GL11.glPushMatrix();
GL11.glTranslatef(bb.origin.x, bb.origin.y, bb.origin.z); // Translation here
GL11.glRotatef(360.0f - yrot, 0, -1.0f, 0);
GL11.glRotatef(lookupdown, -1.0f, 0, 0);
GL11.glBegin(GL11.GL_QUADS);
GL11.glVertex3f(0.5f, 0.5f, 0); // No translation here anymore
GL11.glVertex3f(0.5f, 0.5f, 0;
GL11.glVertex3f(0.5f, 0.5f, 0);
GL11.glVertex3f(0.5f, 0.5f, 0);
GL11.glEnd();
On a separate note, you're not using a conventional billboarding technique. Rather than having the billboards always face the camera, you're having them always be perpendicular to the camera. This will be noticeable for billboard objects near the edges of your view frustrum. I'll leave it up to you to look into this further though!
Hi I'm creating a water scene and have a class called drawWater. The class takes in a equation to alter it's appearance. When I try to create
drawater water = new drawWater();
drawater water2 = new drawWater();
They both seem to be created with the correct values but when I draw them onto the screen only one is shown. Both the values are different.
I don't know where I'm going wrong. It doesn't seem to be a JOGL problem but the way I'm setting up the class?
Can anyone see where I went wrong?
This is the main class:
package waterAttempt41;
import Common.GLDisplay;
public class Lesson27 {
public static void main(String[] args) {
GLDisplay neheGLDisplay = GLDisplay.createGLDisplay("Current water attempt");
Renderer renderer = new Renderer();
//InputHandler inputHandler = new InputHandler(renderer, neheGLDisplay);
neheGLDisplay.addGLEventListener(renderer);
//neheGLDisplay.addKeyListener(inputHandler);
neheGLDisplay.start();
}
}
This is the renderer class:
package waterAttempt41;
import Common.TextureReader;
import java.io.IOException;
import java.util.logging.Logger;
import javax.media.opengl.GL;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.glu.GLU;
class Renderer implements GLEventListener {
private static final Logger logger = Logger.getLogger(Renderer.class.getName());
drawWater water;
drawWater water2;
private int[] textures = new int[3]; // Storage For 3 Textures
private boolean aDown = false;
private boolean up = false;
private GLU glu = new GLU();
public void init(GLAutoDrawable drawable) {
GL gl = drawable.getGL();
try {
loadGLTextures(drawable);
} catch (IOException e) {
logger.info("Exception loading textures or Objects");
System.out.println("Couldn't load model/Texture");
throw new RuntimeException(e);
}
gl.glEnable(GL.GL_DEPTH_TEST);
gl.glShadeModel(GL.GL_SMOOTH);
gl.glLightModeli(GL.GL_LIGHT_MODEL_TWO_SIDE, GL.GL_TRUE);
gl.glCullFace(GL.GL_BACK); // Set Culling Face To Back Face
gl.glEnable(GL.GL_CULL_FACE); // Enable Culling
gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Set Clear Color (Greenish Color)
float spot_ambient[] = {0.2f, 0.2f, 0.2f, 1.0f};
float spot_diffuse[] = {10.2f, 10.2f, 10.2f, 10.0f};
float spot_specular[] = {10.2f, 10.2f, 10.2f, 10.0f};
gl.glLightfv(GL.GL_LIGHT0, GL.GL_AMBIENT, spot_ambient, 1);
gl.glLightfv(GL.GL_LIGHT0, GL.GL_DIFFUSE, spot_diffuse, 1);
gl.glLightfv(GL.GL_LIGHT0, GL.GL_SPECULAR, spot_specular, 1);
gl.glEnable(GL.GL_LIGHTING);
gl.glEnable(GL.GL_LIGHT0);
water = new drawWater();
water.setup(gl, "a*sin( y *(x-b) )");
water.setFuncVar('a', 1.103);
water.setFuncVar('b', 1.103);
water.setMax(5);
water2 = new drawWater();
water2.setup(gl, "a*sin( y *(x-b) )");
water2.setFuncVar('a', 0.05);
water2.setFuncVar('b', 10.0);
water2.setMax(25);
}
public void display(GLAutoDrawable drawable) {
GL gl = drawable.getGL();
// Clear Color Buffer, Depth Buffer, Stencil Buffer
gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT | GL.GL_STENCIL_BUFFER_BIT);
logger.info("\nWater: a = " + water.getFuncVar('a') + " b =" + water.getFuncVar('b') + "\n"
+ "Water2: a = " + water2.getFuncVar('a') + " b =" + water2.getFuncVar('b')
+ "\nWater: = " + water.getEqu() + " \nWater2 =" + water2.getEqu()
+ "\nWater: max = " + water.getMax() + " Water2: max = " + water2.getMax());
gl.glPushMatrix();
gl.glTranslatef(0.0f, -20.50f, 0.0f);
gl.glTranslatef(0.0f, 0.0f, -31.0f);
gl.glRotatef(90, 0.0f, 0.0f, 1.0f); // Rotate By -yrot On Y Axis
gl.glRotatef(90, 0.0f, 1.0f, 0.0f);
water.draw(gl);
gl.glTranslatef(0.0f, -20.0f, 0.0f);
water2.draw(gl);
gl.glPopMatrix();
gl.glPushMatrix();
gl.glTranslatef(0.0f, 0.0f, -20.0f); // Zoom Into The Screen 20 Units
gl.glEnable(GL.GL_TEXTURE_2D); // Enable Texture Mapping ( NEW )
drawRoom(gl); // Draw The Room
gl.glPopMatrix();
gl.glFlush(); // Flush The OpenGL Pipeline
}
private void drawRoom(GL gl) { // Draw The Room (Box)
gl.glBegin(GL.GL_QUADS); // Begin Drawing Quads
/*
// Floor
gl.glNormal3f(0.0f, 1.0f, 0.0f); // Normal Pointing Up
gl.glVertex3f(-20.0f, -20.0f, -40.0f); // Back Left
gl.glVertex3f(-20.0f, -20.0f, 40.0f); // Front Left
gl.glVertex3f(20.0f, -20.0f, 40.0f); // Front Right
gl.glVertex3f(20.0f, -20.0f, -40.0f); // Back Right
// Ceiling
gl.glNormal3f(0.0f, -1.0f, 0.0f); // Normal Point Down
gl.glVertex3f(-10.0f, 10.0f, 20.0f); // Front Left
gl.glVertex3f(-10.0f, 10.0f, -20.0f); // Back Left
gl.glVertex3f(10.0f, 10.0f, -20.0f); // Back Right
gl.glVertex3f(10.0f, 10.0f, 20.0f); // Front Right
// Back Wall
gl.glNormal3f(0.0f, 0.0f, -1.0f); // Normal Pointing Towards Viewer
gl.glVertex3f(20.0f, 20.0f, 30.0f); // Top Right
gl.glVertex3f(20.0f, -20.0f, 30.0f); // Bottom Right
gl.glVertex3f(-20.0f, -20.0f, 30.0f); // Bottom Left
gl.glVertex3f(-20.0f, 20.0f, 30.0f); // Top Left
// Left Wall
gl.glNormal3f(1.0f, 0.0f, 0.0f); // Normal Pointing Right
gl.glVertex3f(-20.0f, 20.0f, 30.0f); // Top Front
gl.glVertex3f(-20.0f, -20.0f, 30.0f); // Bottom Front
gl.glVertex3f(-20.0f, -20.0f, -30.0f); // Bottom Back
gl.glVertex3f(-20.0f, 20.0f, -30.0f); // Top Back
// Right Wall
gl.glNormal3f(-1.0f, 0.0f, 0.0f); // Normal Pointing Left
gl.glVertex3f(20.0f, 20.0f, -30.0f); // Top Back
gl.glVertex3f(20.0f, -20.0f, -30.0f); // Bottom Back
gl.glVertex3f(20.0f, -20.0f, 30.0f); // Bottom Front
gl.glVertex3f(20.0f, 20.0f, 30.0f); // Top Front
*/
// Front Wall
gl.glNormal3f(0.0f, 0.0f, 1.0f); // Normal Pointing Away From Viewer
gl.glTexCoord2f(1, 1);
gl.glVertex3f(-20.0f, 20.0f, -30.0f); // Top Left
gl.glTexCoord2f(1, 0);
gl.glVertex3f(-20.0f, -20.0f, -30.0f); // Bottom Left
gl.glTexCoord2f(0, 0);
gl.glVertex3f(20.0f, -20.0f, -30.0f); // Bottom Right
gl.glTexCoord2f(0, 1);
gl.glVertex3f(20.0f, 20.0f, -30.0f); // Top Right
gl.glPopMatrix();
gl.glEnd(); // Done Drawing Quads
}
public void reshape(GLAutoDrawable drawable, int xstart, int ystart, int width, int height) {
GL gl = drawable.getGL();
height = (height == 0) ? 1 : height;
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL.GL_PROJECTION);
gl.glLoadIdentity();
gl.glRotatef(90, 0.0f, 0.0f, 1.0f);
glu.gluPerspective(60, (float) width / height, 1, 1000);
glu.gluLookAt(1.0f, 0.0f, 25.0f,
0.0f, 0.0f, 0.0f,
0.0f, 0.0f, 1.0f);
gl.glMatrixMode(GL.GL_MODELVIEW);
gl.glLoadIdentity();
}
public void displayChanged(GLAutoDrawable drawable, boolean modeChanged, boolean deviceChanged) {
}
private void loadGLTextures(GLAutoDrawable gldrawable) throws IOException {
TextureReader.Texture texture = null;
texture = TextureReader.readTexture("data/images/042.bmp");
GL gl = gldrawable.getGL();
//Create Nearest Filtered Texture
gl.glGenTextures(1, textures, 0);
gl.glBindTexture(GL.GL_TEXTURE_2D, textures[0]);
gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MAG_FILTER, GL.GL_LINEAR);
gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MIN_FILTER, GL.GL_LINEAR);
gl.glTexImage2D(GL.GL_TEXTURE_2D,
0,
3,
texture.getWidth(),
texture.getHeight(),
0,
GL.GL_RGB,
GL.GL_UNSIGNED_BYTE,
texture.getPixels());
}
}
The drawWater Class:
import com.sun.opengl.util.BufferUtil;
import javax.media.opengl.GL;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
/**
*
* #author Shane
*/
public class drawWater {
private Expr2 func; // The function that is being drawn.
private String functionInput;
private boolean version_1_5; // Check is OpenGL 1.5 is available; set in init().
private boolean dataIsValid; // Set to true whenever data needs to be recomputed.
// This is checked in the display() method before drawing.
private int max;
/* Buffers to hold the points and normals for the surface. */
private FloatBuffer vBuf = BufferUtil.newFloatBuffer(201 * 201 * 3);
private FloatBuffer nBuf = BufferUtil.newFloatBuffer(201 * 201 * 3);
/* Buffers to hold the indices for drawing the surface and lines with glDrawElements*/
private IntBuffer surfaceIndexBuffer = BufferUtil.newIntBuffer(200 * 201 * 2);
private IntBuffer xLineIndexBuffer = BufferUtil.newIntBuffer(21 * 201);
private IntBuffer yLineIndexBuffer = BufferUtil.newIntBuffer(21 * 201);
/* VBO ID numbers for holding the data when OpenGL version is 1.5 or higher */
private int vertexVBO, normalVBO; // VBO IDs for surface data.
private int xLineVBO, yLineVBO, surfaceVBO; // VBO IDs for index data.
public drawWater() {
}
public void setup(GL gl, String equ) {
version_1_5 = gl.isExtensionAvailable("GL_VERSION_1_5");
if (gl.isExtensionAvailable("GL_VERSION_1_3")) {
gl.glEnable(GL.GL_MULTISAMPLE);
}
this.makeElementBuffers(); // Generate lists of indices for glDrawElements. This data never changes.
if (version_1_5) {
// Generate VBOs for the data, and fill the ones that are for index data with
// data from Java nio buffers. The VBOs for index data won't change again and
// so use GL.GL_STATIC_DRAW.
int[] ids = new int[5];
gl.glGenBuffers(5, ids, 0);
this.vertexVBO = ids[0];
this.normalVBO = ids[1];
this.xLineVBO = ids[2];
this.yLineVBO = ids[3];
this.surfaceVBO = ids[4];
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, vertexVBO);
gl.glVertexPointer(3, GL.GL_FLOAT, 0, 0);
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, normalVBO);
gl.glNormalPointer(GL.GL_FLOAT, 0, 0);
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, 0);
gl.glBindBuffer(GL.GL_ELEMENT_ARRAY_BUFFER, surfaceVBO);
gl.glBufferData(GL.GL_ELEMENT_ARRAY_BUFFER, 4 * 2 * 200 * 201, surfaceIndexBuffer, GL.GL_STATIC_DRAW);
gl.glBindBuffer(GL.GL_ELEMENT_ARRAY_BUFFER, xLineVBO);
gl.glBufferData(GL.GL_ELEMENT_ARRAY_BUFFER, 4 * 21 * 201, xLineIndexBuffer, GL.GL_STATIC_DRAW);
gl.glBindBuffer(GL.GL_ELEMENT_ARRAY_BUFFER, yLineVBO);
gl.glBufferData(GL.GL_ELEMENT_ARRAY_BUFFER, 4 * 21 * 201, yLineIndexBuffer, GL.GL_STATIC_DRAW);
gl.glBindBuffer(GL.GL_ELEMENT_ARRAY_BUFFER, 0);
} else {
gl.glVertexPointer(3, GL.GL_FLOAT, 0, vBuf);
gl.glNormalPointer(GL.GL_FLOAT, 0, nBuf);
}
this.functionInput = equ;
this.func = new Expr2(equ);
this.dataIsValid = false; // Force recomputation of data with new graph definition.
}
public void draw(GL gl) {
if (func != null) {
gl.glMaterialfv(GL.GL_FRONT, GL.GL_AMBIENT_AND_DIFFUSE, new float[]{0.7f, 10.7f, 1}, 0);
gl.glMaterialfv(GL.GL_BACK, GL.GL_AMBIENT_AND_DIFFUSE, new float[]{10.8f, 0.8f, 0.5f}, 0);
if (!dataIsValid) {
this.computeSurfaceData();
if (version_1_5) {
// Set up VBOs for surface points and normals. Since these change
// pretty regularly, use GL.GL_DYNAMIC_DRAW.
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, vertexVBO);
gl.glBufferData(GL.GL_ARRAY_BUFFER, 4 * 3 * 201 * 201, vBuf, GL.GL_DYNAMIC_DRAW);
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, normalVBO);
gl.glBufferData(GL.GL_ARRAY_BUFFER, 4 * 3 * 201 * 201, nBuf, GL.GL_DYNAMIC_DRAW);
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, 0);
}
}
gl.glEnableClientState(GL.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL.GL_NORMAL_ARRAY);
this.drawSurface(gl); // Just draw the surface.
gl.glPolygonOffset(1, 1);
gl.glEnable(GL.GL_POLYGON_OFFSET_FILL);
this.drawSurface(gl);
gl.glDisable(GL.GL_POLYGON_OFFSET_FILL);
gl.glDisable(GL.GL_LIGHTING);
gl.glColor3f(0, 0, 0);
gl.glDisableClientState(GL.GL_NORMAL_ARRAY);
gl.glEnable(GL.GL_LIGHTING);
}
gl.glDisableClientState(GL.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL.GL_NORMAL_ARRAY);
}
public void setIsVaild(boolean bool) {
this.dataIsValid = bool;
}
public void setMax(int max) {
this.max = max;
}
public int getMax() {
return this.max;
}
public double getFuncVar(char var) {
return this.func.getVariable(var);
}
public void setFuncVar(char var, double value) {
this.func.setVariable(var, value);
}
public void setFunc(String func) {
this.func.parse(func);
}
public String getEqu() {
return this.functionInput;
}
private void makeElementBuffers() {
for (int i = 0; i < 201; i += 10) { // indices for drawing lines in x-direction
for (int j = 0; j < 201; j++) {
this.xLineIndexBuffer.put(201 * i + j);
}
}
for (int i = 0; i < 201; i += 10) { // indices for drawing lines in y-direction
for (int j = 0; j < 201; j++) {
this.yLineIndexBuffer.put(201 * j + i);
}
}
for (int i = 0; i < 200; i++) { // indices for drawing surface with GL_TRIANGLE_STRIPs
for (int j = 0; j < 201; j++) {
this.surfaceIndexBuffer.put(201 * (i + 1) + j);
this.surfaceIndexBuffer.put(201 * i + j);
}
}
this.xLineIndexBuffer.rewind();
this.yLineIndexBuffer.rewind();
this.surfaceIndexBuffer.rewind();
}
private void computeSurfaceData() {
double xmin = -5;
double xmax = 5;
double ymin = -5;
double ymax = 5;
double xRes = 200;
double yRes = 200;
float[] surfaceData = new float[301 * 3];
float[] normalData = new float[301 * 3];
double dx = (xmax - xmin) / xRes;
double dy = (ymax - ymin) / yRes;
for (int i = 0; i <= xRes; i++) {
int v = 0;
int n = 0;
double y1 = ymin + dy * i;
for (int j = 0; j <= yRes; j++) {
double x = xmin + dx * j;
this.func.setVariable('x', x);
this.func.setVariable('y', y1);
double z1 = this.func.value();
float[] normal1 = computeUnitNormal(x, y1);
surfaceData[v++] = (float) x;
surfaceData[v++] = (float) y1;
surfaceData[v++] = (float) z1;
normalData[n++] = normal1[0];
normalData[n++] = normal1[1];
normalData[n++] = normal1[2];
}
this.vBuf.put(surfaceData, 0, 201 * 3);
this.nBuf.put(normalData, 0, 201 * 3);
}
this.vBuf.rewind();
this.nBuf.rewind();
this.dataIsValid = true;
}
/**
* Draw the surface as a series of triangle strips.
*/
private void drawSurface(GL gl) {
if (version_1_5) {
gl.glBindBuffer(GL.GL_ELEMENT_ARRAY_BUFFER, surfaceVBO);
for (int i = 0; i < 200; i++) {
gl.glDrawElements(GL.GL_TRIANGLE_STRIP, 402, GL.GL_UNSIGNED_INT, 402 * i * 4);
}
gl.glBindBuffer(GL.GL_ELEMENT_ARRAY_BUFFER, 0);
} else {
for (int i = 0; i < 200; i++) {
this.surfaceIndexBuffer.position(402 * i);
gl.glDrawElements(GL.GL_TRIANGLE_STRIP, 402, GL.GL_UNSIGNED_INT, surfaceIndexBuffer);
}
}
}
/**
* Compute a unit normal to the graph of z = func(x,y).
* This is only an approximation, using nearby points instead
* of exact derivatives.
*/
private float[] computeUnitNormal(double x, double y) {
double epsilon = 0.00001;
this.func.setVariable('x', x);
this.func.setVariable('y', y);
double z = this.func.value();
this.func.setVariable('x', x + epsilon);
double z1 = func.value();
this.func.setVariable('x', x);
this.func.setVariable('y', y + epsilon);
double z2 = this.func.value();
// normal is (epsilon,0,z1-z) X (0,epsilon,z2-z)
double a = -epsilon * (z1 - z);
double b = -epsilon * (z2 - z);
double c = epsilon * epsilon;
double length = Math.sqrt(a * a + b * b + c * c);
if (Double.isNaN(length) || Double.isInfinite(length)) {
return new float[]{0, 0, 1};
} else {
return new float[]{(float) (a / length), (float) (b / length), (float) (c / length)};
}
}
}
Any help would be a appreciated. This is part of my final year project in college. So any help would be great.
The calls to glVertexPointer/glNormalPointer are not done per draw, but per setup.
So, when you create the 2 drawWater objects, the last one leaves its vertex and normal data bound to the GL, which all the calls to glDrawElements will use.
You need to modify the code so that glVertexPointer/glNormalPointer (along with the glBindBuffer calls that accompany them) are done per draw.