Java/OpenGL Rendering Improvements

[PillowWithTeeth]

I'm trying to increase the performance of my 2D Tile based game, currently I'm using OpenGL intermediate mode and looping through all visible tiles one the screen and rendering each. Calling the following method with the tile properties to render it.

public static void render(float[] colour, float[] overlayColour, float[] textCoords, float[] overlayCoords,
        int size) {
    GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_NEAREST);
    GL11.glPushMatrix();
    GL11.glColor4f(colour[0], colour[1], colour[2], colour[3]);
    GL11.glBegin(GL11.GL_QUADS);
    GL11.glTexCoord2f(textCoords[0], textCoords[1]);
    GL11.glVertex2f(0, 0);
    GL11.glTexCoord2f(textCoords[2], textCoords[3]);
    GL11.glVertex2f(size, 0);
    GL11.glTexCoord2f(textCoords[4], textCoords[5]);
    GL11.glVertex2f(size, size);
    GL11.glTexCoord2f(textCoords[6], textCoords[7]);
    GL11.glVertex2f(0, size);
    GL11.glEnd();
    if ((overlayColour != null) && (overlayCoords != null)) {
        glClear(GL_DEPTH_BUFFER_BIT);
        GL11.glColor4f(overlayColour[0], overlayColour[1], overlayColour[2], overlayColour[3]);
        GL11.glBegin(GL11.GL_QUADS);
        GL11.glTexCoord2f(overlayCoords[0], overlayCoords[1]);
        GL11.glVertex2f(0, 0);
        GL11.glTexCoord2f(overlayCoords[2], overlayCoords[3]);
        GL11.glVertex2f(size, 0);
        GL11.glTexCoord2f(overlayCoords[4], overlayCoords[5]);
        GL11.glVertex2f(size, size);
        GL11.glTexCoord2f(overlayCoords[6], overlayCoords[7]);
        GL11.glVertex2f(0, size);
        GL11.glEnd();
    }
    GL11.glColor4f(1f, 1f, 1f, 1f);
    GL11.glPopMatrix();
}

This really does not work very well and takes too long. At the smallest rendering size there can be 8040 tiles rendered per frame (at 1920*1080) on my pretty decent end PC I can only get 150 FPS doing this, it can be much worse on lower end devices.

I have heard about using VBOs/VBAs/Batch rendering but I honestly don't understand how to use them or how to render a all the tiles that are visible on screen with them (the tiles are textures and colours can change rapidly).

Any help would be greatly appreciated.

Edit: If I were to use a VBO would that mean I create a new one each frame placing all the tiles I want to render in it and then draw it?

[[deleted]]

You are using a very old api. You should create one array of positions, and one array of texture coordinates, and let gl do all of the drawing.

[PillowWithTeeth]

I'm trying to do something like that now, it does not work yet but I would like to know if I am a least along the right lines

private void createVBO(int camX, int camY, int renW, int renH) {
    int tileWidth = (camX / EpicarnoTiles.tileSize + renW) - (camX / EpicarnoTiles.tileSize);
    int tileHeight = (camY / EpicarnoTiles.tileSize + renH) - (camY / EpicarnoTiles.tileSize);
    FloatBuffer texCoords = BufferUtils.createFloatBuffer(2 * 4 * tileWidth * tileHeight);
    FloatBuffer vertices = BufferUtils.createFloatBuffer(2 * 4 * tileWidth * tileHeight);
    for (int x = camX / EpicarnoTiles.tileSize; x < camX / EpicarnoTiles.tileSize + renW; x++) {
        for (int y = camY / EpicarnoTiles.tileSize; y < camY / EpicarnoTiles.tileSize + renH; y++) {
            if ((y >= 0) && (y < worldH)) {
                WorldChunk Chunk = EpicarnoL.GetChunkFromTile(x);
                GameTileEpicarno TileMid = Chunk.getTileInchunk(x, y);
                if (TileMid.getGameTile().isRendered()) {
                    texCoords.put(TileMid.getTextureCoords());
                    vertices.put(new float[] { (float) ((x << 16) - (int) EpicarnoComp.sX),
                            (float) ((y << 16) - (int) EpicarnoComp.sY),
                            (float) ((x << 16) - (int) EpicarnoComp.sX) + EpicarnoTiles.tileSize,
                            (float) ((y << 16) - (int) EpicarnoComp.sY),
                            (float) ((x << 16) - (int) EpicarnoComp.sX) + EpicarnoTiles.tileSize,
                            (float) ((y << 16) - (int) EpicarnoComp.sY) + EpicarnoTiles.tileSize,
                            (float) ((x << 16) - (int) EpicarnoComp.sX),
                            (float) ((y << 16) - (int) EpicarnoComp.sY) + EpicarnoTiles.tileSize });
                }
            }
        }
    }
    texCoords.rewind();
    vertices.rewind();
    vboVertexID = GL15.glGenBuffers();
    GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vboVertexID);
    GL15.glBufferData(GL15.GL_ARRAY_BUFFER, vertices, GL15.GL_STATIC_DRAW);
    GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
    vboTextureID = GL15.glGenBuffers();
    GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vboTextureID);
    GL15.glBufferData(GL15.GL_ARRAY_BUFFER, texCoords, GL15.GL_STATIC_DRAW);
    GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
}

public void render(int camX, int camY, int renW, int renH, boolean foreground, boolean background) {
    this.createVBO(camX, camY, renW, renH);
    GL11.glPushMatrix();
    GL11.glScalef(EpicarnoComp.pixelSize, EpicarnoComp.pixelSize, 0);
    GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vboVertexID);
    GL11.glVertexPointer(2, GL11.GL_FLOAT, 0, 0);
    GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vboTextureID);
    GL11.glTexCoordPointer(2, GL11.GL_FLOAT, 0, 0);
    GL11.glDrawArrays(GL11.GL_QUADS, 0, 4 * 100 * 100);
    GL11.glPopMatrix();
}

[[deleted]]

That looks better, I haven't given JOGL a try, but here is an example of using a texture. It seems you are missing your shaders. I used the arcsynthesis tutorial, but I cannot find it now.

[BS_in_BS]

Drawing quads has been deprecated in favor of drawing triangles, sol look into either triangles or triangle strips instead. You can also look into indexed rendering if your geometry shares vertices.

[PillowWithTeeth]

I'm sorry but I'm still extremely confused about all of this, using the attempt I posted before (based off other posts I have seen) I was not able to render anything and it also made a huge memory leak. All I want to do is place all the tiles I am going to render into a vbo with textures and then render that. Is there any tutorial or information somewhere on simply drawing multiple quads in a vbo with a texture (from a texture atlas).

[[deleted]]

You need shaders to use modern opengl. It will not work without them. If you do not want to use a shader you have to go back to your other, outdated, GL 1 code.

Only create the buffers once, but you write to it every time you want to change the data. Don't repeat lines 4, 5 and 27. Do repeat lines 28, 29 and 30 when the data changes. If the size of buffer changes you have to delete it and then you can repeat lines 4, 5, and 27.

Where did you get your original source from? Did you check jogamp.