Problem displaying point sprites

Apprentice

Posts: 5
Joined: 2010.02

Post: #1

Feb 12, 2010 — 02:45 AM

I'm trying to write a simple particle system, and I'm trying to use point sprites to represent each particle for performance sake. However, I must be missing something when trying to draw my point sprites, because I can't get them to show up on screen. I can verify that they are being updated correctly because if I copy the data into individual triangle strips and draw that, the particles display correctly. I store the particles in the following struct and am attempting to use the following drawing code, with no success:

Code:

//A Vector3D is an x,y,z position using three floats

//A Color3D is an RGBA color using four floats

typedef struct

 {

    Color3D color;

    float energy;

    Vector3D position;

    Vector3D velocity;

    float scale;

} Particle;

Code:

    glEnableClientState(GL_POINT_SPRITE_OES);

    glEnableClientState(GL_VERTEX_ARRAY);

    glEnableClientState(GL_COLOR_ARRAY);

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity();

        glBindTexture(GL_TEXTURE_2D, 6);

    glVertexPointer(3, GL_FLOAT, sizeof(Particle), &particles[0].position);

    glColorPointer(4, GL_FLOAT, sizeof(Particle), &particles[0].color);

        glPointSizePointerOES(GL_FLOAT, sizeof(Particle), &particles[0].scale);

        glDrawArrays(GL_POINTS, 0, arraylength);

        glDisableClientState(GL_POINT_SPRITE_OES);

    glDisableClientState(GL_VERTEX_ARRAY);

    glDisableClientState(GL_COLOR_ARRAY);

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