# OpenGL Some question: moving object, draw a ball, bouncing ball

## Recommended Posts

bako    122
Hi all. i've some trouble in opengl. 1) how i can automaticaly move a object? i.e. i would that my ball is moving into my window?. if i modify the value of the matrix using translatematix i didn't see anything because the display is done too fast. there is a method to move the object? 2) how i can draw a ball? i've seen the gluSphere, there's some problem using this function? i try this code, but dosen't work.
    private void drawBall(GL gl) {
ArrayList etas = new ArrayList();
ArrayList fis = new ArrayList();
int mslice = 10;
int nslice = 50;
double eta;
double fi;
ArrayList<Vertex3d> vertex = new ArrayList<Vertex3d>();
for (int i = 0; i < nslice - 1; i++) {
eta = ((2 * Math.PI) / nslice) * i;
}
for (int j = 0; j < mslice; j++) {
fi = -1 * (Math.PI / 2) + (Math.PI / mslice) * j;
}
for (int j = 0; j < fis.size(); j++) {
for (int i = 0; i < etas.size(); i++) {
eta = Double.valueOf("" + etas.get(i)).doubleValue();
fi = Double.valueOf("" + fis.get(j)).doubleValue();
Vertex3d v = new Vertex3d(Math.cos(eta) * Math.sin(fi), Math.sin(eta) * Math.sin(fi), Math.cos(fi));
}
}
gl.glColor3f(1.0f, 0.0f, 0.0f);
gl.glBegin(GL.GL_TRIANGLES);
for (int i = 0; i < nslice; i++) {
int j = 0;
gl.glVertex3d(vertex.get(j).x, vertex.get(j).y, vertex.get(j).z);
gl.glVertex3d(vertex.get(j + i + 1).x, vertex.get(j + i + 1).y, vertex.get(j + i + 1).z);
gl.glVertex3d(vertex.get(j + i + 1 + 1).x, vertex.get(j + i + 1 + 1).y, vertex.get(j + i + 1 + 1).z);
gl.glVertex3d(vertex.get(j).x, vertex.get(j).y, vertex.get(j).z);
gl.glVertex3d(vertex.get(j + 1 + (nslice - 1)).x, vertex.get(j + 1 + (nslice - 1)).y, vertex.get(j + 1 + (nslice - 1)).z);
gl.glVertex3d(vertex.get(j + 1).x, vertex.get(j + 1).y, vertex.get(j + 1).z);

}
gl.glEnd();
gl.glColor3f(0.0f, 1.0f, 0.0f);
for (int i = 0; i < nslice - 1; i++) {
for (int j = 1; j < mslice; j++) {
gl.glVertex3d(vertex.get(j + i).x, vertex.get(j + i).y, vertex.get(j + i).z);
gl.glVertex3d(vertex.get(j + i + 1).x, vertex.get(j + i + 1).y, vertex.get(j + i + 1).z);
gl.glVertex3d(vertex.get(j + nslice + i + 1).x, vertex.get(j + nslice + i + 1).y, vertex.get(j + nslice + i + 1).z);
gl.glVertex3d(vertex.get(j + nslice + i).x, vertex.get(j + nslice + i).y, vertex.get(j + nslice + i).z);
gl.glVertex3d(vertex.get(j + (nslice - 1)).x, vertex.get(j + (nslice - 1)).y, vertex.get(j + (nslice - 1)).z);
gl.glVertex3d(vertex.get(j + 0).x, vertex.get(j + 0).y, vertex.get(j + 0).z);
gl.glVertex3d(vertex.get(j + nslice).x, vertex.get(j + nslice).y, vertex.get(j + nslice).z);
gl.glVertex3d(vertex.get(j + nslice + (nslice - 1)).x, vertex.get(j + nslice + (nslice - 1)).y, vertex.get(j + nslice + (nslice - 1)).z);

}
}
gl.glEnd();
}

3) someone of you have code about bouncing ball (java preferd). thanks.

## Create an account

Register a new account

• ### Similar Content

• Hello. I'm Programmer who is in search of 2D game project who preferably uses OpenGL and C++. You can see my projects in GitHub. Project genre doesn't matter (except MMO's :D).

• Hello, My name is Matt. I am a programmer. I mostly use Java, but can use C++ and various other languages. I'm looking for someone to partner up with for random projects, preferably using OpenGL, though I'd be open to just about anything. If you're interested you can contact me on Skype or on here, thank you!
Skype: Mangodoor408
• By tyhender
Hello, my name is Mark. I'm hobby programmer.
So recently,I thought that it's good idea to find people to create a full 3D engine. I'm looking for people experienced in scripting 3D shaders and implementing physics into engine(game)(we are going to use the React physics engine).
And,ye,no money =D I'm just looking for hobbyists that will be proud of their work. If engine(or game) will have financial succes,well,then maybe =D
Sorry for late replies.
I mostly give more information when people PM me,but this post is REALLY short,even for me =D
So here's few more points:
Engine will use openGL and SDL for graphics. It will use React3D physics library for physics simulation. Engine(most probably,atleast for the first part) won't have graphical fron-end,it will be a framework . I think final engine should be enough to set up an FPS in a couple of minutes. A bit about my self:
I've been programming for 7 years total. I learned very slowly it as "secondary interesting thing" for like 3 years, but then began to script more seriously.  My primary language is C++,which we are going to use for the engine. Yes,I did 3D graphics with physics simulation before. No, my portfolio isn't very impressive. I'm working on that No,I wasn't employed officially. If anybody need to know more PM me.

• By Zaphyk
I am developing my engine using the OpenGL 3.3 compatibility profile. It runs as expected on my NVIDIA card and on my Intel Card however when I tried it on an AMD setup it ran 3 times worse than on the other setups. Could this be a AMD driver thing or is this probably a problem with my OGL code? Could a different code standard create such bad performance?

• I'm trying to get some legacy OpenGL code to run with a shader pipeline,
The legacy code uses glVertexPointer(), glColorPointer(), glNormalPointer() and glTexCoordPointer() to supply the vertex information.
I know that it should be using setVertexAttribPointer() etc to clearly define the layout but that is not an option right now since the legacy code can't be modified to that extent.
I've got a version 330 vertex shader to somewhat work:
#version 330 uniform mat4 osg_ModelViewProjectionMatrix; uniform mat4 osg_ModelViewMatrix; layout(location = 0) in vec4 Vertex; layout(location = 2) in vec4 Normal; // Velocity layout(location = 3) in vec3 TexCoord; // TODO: is this the right layout location? out VertexData { vec4 color; vec3 velocity; float size; } VertexOut; void main(void) { vec4 p0 = Vertex; vec4 p1 = Vertex + vec4(Normal.x, Normal.y, Normal.z, 0.0f); vec3 velocity = (osg_ModelViewProjectionMatrix * p1 - osg_ModelViewProjectionMatrix * p0).xyz; VertexOut.velocity = velocity; VertexOut.size = TexCoord.y; gl_Position = osg_ModelViewMatrix * Vertex; } What works is the Vertex and Normal information that the legacy C++ OpenGL code seem to provide in layout location 0 and 2. This is fine.
What I'm not getting to work is the TexCoord information that is supplied by a glTexCoordPointer() call in C++.
Question:
What layout location is the old standard pipeline using for glTexCoordPointer()? Or is this undefined?

Side note: I'm trying to get an OpenSceneGraph 3.4.0 particle system to use custom vertex, geometry and fragment shaders for rendering the particles.

• 10
• 11
• 24
• 26
• 17