EXCEPTION_ACCESS_VIOLATION with glDrawArrays()

[Fool Running]

I have a game engine I wrote using GL4Java and am porting it to lwjgl to see how it is.  When I use the glDrawArrays() I get the EXCEPTION_ACCESS_VIOLATION error thrown.  If anyone knows what might cause this it would be nice

Heres the code snipet (sorry its a little messy  :oops: )

       // setup buffers
       ByteBuffer temp = ByteBuffer.allocateDirect(polyCount * vertexCount * 3 * 4);
       temp.order(ByteOrder.nativeOrder());
       vertexBuffer = temp.asFloatBuffer().put(vertexArray);
       vertexBuffer.flip();
       temp = ByteBuffer.allocateDirect(polyCount * vertexCount * 4 * 4);
       temp.order(ByteOrder.nativeOrder());
       colorBuffer = temp.asFloatBuffer().put(colorArray);
       colorBuffer.flip();
       temp = ByteBuffer.allocateDirect(polyCount * vertexCount * 3 * 4);
       temp.order(ByteOrder.nativeOrder());
       normalBuffer = temp.asFloatBuffer().put(normalArray);
       normalBuffer.flip();
       temp = ByteBuffer.allocateDirect(polyCount * vertexCount * 2 * 4);
       temp.order(ByteOrder.nativeOrder());
       texBuffer = temp.asFloatBuffer().put(texArray);
       texBuffer.flip();
       // setup for array drawing
       GL.glVertexPointer(3, GL.GL_FLOAT, vertexBuffer);
       GL.glColorPointer(4, GL.GL_FLOAT, colorBuffer);
       GL.glNormalPointer(GL.GL_FLOAT, normalBuffer);
       GL.glTexCoordPointer(2, GL.GL_FLOAT, texBuffer);

       GL.glDrawArrays(GL.GL_TRIANGLES, 0, polyCount * vertexCount);

The GL.glDrawArrays(...) is called creating a displaylist (if it matters  :roll: )

[Fool Running]

polyCount is the number of polygons to render.
vertexCount is the number of vertexes per polygon.

[elias]

Have you enabled the arrays with glEnabledClientState()? And are you sure that the arrays you put() have size = vc*pc*(element size)?

- elias

[Fool Running]

Have you enabled the arrays with glEnabledClientState()? And are you sure that the arrays you put() have size = vc*pc*(element size)?

Yeah, all the client states are initialized and the arrays and the buffers all have the correct sizes.

The exact same code (aside from the Buffers) runs fine in GL4Java so I assume it has something to do with the Buffers (I'm new to the Buffer thing  :lol: ).

Here is the entire method if it might help:

       int vertexCount = getNumOfVertexesPerPolygon();
        float[] vertexArray = new float[polyCount * vertexCount * 3];
        float[] normalArray = new float[polyCount * vertexCount * 3];
        float[] colorArray = new float[polyCount * vertexCount * 4];
        float[] texArray = new float[polyCount * vertexCount * 2];
        vertexPlace = normalPlace = colorPlace = texPlace = 0;
        // add data to arrays
        for(int i = 0; i < polyCount; i++){
            piece[i].addVertexesToArray(vertexArray, vertexPlace);
            piece[i].addColorsToArray(colorArray, colorPlace);
            piece[i].addNormalsToArray(normalArray, normalPlace);
            piece[i].addTexCoordsToArray(texArray, texPlace);
            vertexPlace += vertexCount * 3;
            colorPlace += vertexCount * 4;
            normalPlace += vertexCount * 3;
            texPlace += vertexCount * 2;
        }
        // setup buffers
        ByteBuffer temp = ByteBuffer.allocateDirect(polyCount * vertexCount * 3 * 4);
        temp.order(ByteOrder.nativeOrder());
        vertexBuffer = temp.asFloatBuffer().put(vertexArray);
        vertexBuffer.flip();
        temp = ByteBuffer.allocateDirect(polyCount * vertexCount * 4 * 4);
        temp.order(ByteOrder.nativeOrder());
        colorBuffer = temp.asFloatBuffer().put(colorArray);
        colorBuffer.flip();
        temp = ByteBuffer.allocateDirect(polyCount * vertexCount * 3 * 4);
        temp.order(ByteOrder.nativeOrder());
        normalBuffer = temp.asFloatBuffer().put(normalArray);
        normalBuffer.flip();
        temp = ByteBuffer.allocateDirect(polyCount * vertexCount * 2 * 4);
        temp.order(ByteOrder.nativeOrder());
        texBuffer = temp.asFloatBuffer().put(texArray);
        texBuffer.flip();
        // setup for array drawing
        GL.glVertexPointer(3, GL.GL_FLOAT, vertexBuffer);
        GL.glColorPointer(4, GL.GL_FLOAT, colorBuffer);
        GL.glNormalPointer(GL.GL_FLOAT, normalBuffer);
        GL.glTexCoordPointer(2, GL.GL_FLOAT, texBuffer);

        // create the display list
        id = GL.glGenLists(1);
        GL.glNewList(id, GL.GL_COMPILE);
            if(texture != null && material.getShininess() != 0){
                material.setSelfOnlySpecular();
                GL.glDisable(GL.GL_TEXTURE_2D);
                GL.glDrawArrays(GL.GL_TRIANGLES, 0, polyCount * vertexCount);

                GL.glBlendFunc(GL.GL_ONE, GL.GL_ONE);
                material.setSelfNotSpecular();
                GL.glEnable(GL.GL_TEXTURE_2D);
                texture.bindSelf();
                GL.glDrawArrays(GL.GL_TRIANGLES, 0, polyCount * vertexCount);
                GL.glBlendFunc(GL.GL_SRC_ALPHA, GL.GL_ONE_MINUS_SRC_ALPHA);
            }else{
                material.setSelf();
                if(texture != null){
                    GL.glEnable(GL.GL_TEXTURE_2D);
                    texture.bindSelf();
                }else{
                    GL.glDisable(GL.GL_TEXTURE_2D);
                }
                GL.glDrawArrays(GL.GL_TRIANGLES, 0, polyCount * vertexCount);
            }
        GL.glEndList();

The code path drops into the else at the bottom  

[Fool Running]

Here is the original GL4Java code that runs fine:

       int vertexCount = getNumOfVertexesPerPolygon();
        vertexArray = new float[polyCount * vertexCount * 3];
        normalArray = new float[polyCount * vertexCount * 3];
        colorArray = new float[polyCount * vertexCount * 4];
        texArray = new float[polyCount * vertexCount * 2];
        vertexPlace = normalPlace = colorPlace = texPlace = 0;
        // add data to arrays
        for(int i = 0; i < polyCount; i++){
            piece[i].addVertexesToArray(vertexArray, vertexPlace);
            piece[i].addColorsToArray(colorArray, colorPlace);
            piece[i].addNormalsToArray(normalArray, normalPlace);
            piece[i].addTexCoordsToArray(texArray, texPlace);
            vertexPlace += vertexCount * 3;
            colorPlace += vertexCount * 4;
            normalPlace += vertexCount * 3;
            texPlace += vertexCount * 2;
        }
        // setup for array drawing
        NovaGL.GL.glVertexPointer(3, NovaGL.GL_FLOAT, 0, vertexArray);
        NovaGL.GL.glColorPointer(4, NovaGL.GL_FLOAT, 0, colorArray);
        NovaGL.GL.glNormalPointer(NovaGL.GL_FLOAT, 0, normalArray);
        NovaGL.GL.glTexCoordPointer(2, NovaGL.GL_FLOAT, 0, texArray);
        // create the display list
        id = NovaGL.GL.glGenLists(1);
        NovaGL.GL.glNewList(id, NovaGL.GL_COMPILE);
            if(texture != null && material.getShininess() != 0){
                material.setSelfOnlySpecular();
                NovaGL.GL.glDisable(NovaGL.GL_TEXTURE_2D);
                NovaGL.GL.glDrawArrays(NovaGL.GL_TRIANGLES, 0, polyCount * vertexCount);

                NovaGL.GL.glBlendFunc(NovaGL.GL_ONE, NovaGL.GL_ONE);
                material.setSelfNotSpecular();
                NovaGL.GL.glEnable(NovaGL.GL_TEXTURE_2D);
                texture.bindSelf();
                NovaGL.GL.glDrawArrays(NovaGL.GL_TRIANGLES, 0, polyCount * vertexCount);
                NovaGL.GL.glBlendFunc(NovaGL.GL_SRC_ALPHA, NovaGL.GL_ONE_MINUS_SRC_ALPHA);
            }else{
                material.setSelf();
                if(texture != null){
                    NovaGL.GL.glEnable(NovaGL.GL_TEXTURE_2D);
                    texture.bindSelf();
                }else{
                    NovaGL.GL.glDisable(NovaGL.GL_TEXTURE_2D);
                }
                NovaGL.GL.glDrawArrays(NovaGL.GL_TRIANGLES, 0, polyCount * vertexCount);
            }
        NovaGL.GL.glEndList();

[elias]

* deleted obviously wrong advice *

- elias

[Fool Running]

Well, I found the problem  :oops:

       

GL.glVertexPointer(3, GL.GL_FLOAT, vertexBuffer);

should be
       

GL.glVertexPointer(3, 0, vertexBuffer);

The middle param is the stride  :oops:


Well, thanks, guys for your help  

[princec]

If it wasn't so horribly inefficient from JNI we'd provide typesafe enums for the GL parameters and this kind of problem wouldn't happen.
On the other hand, we might still be able to do it from the Java side without any loss of efficiency.
We would most likely only be able to provide a single GL enum class however so we wouldn't be able to check all the parameters nicely

Cas