2D Tile problems, any ideas?

OpenGL Development
#1

Hi!
I have a 2D engine (ortho mode and frustrum, does not matter) which tiles the screen with 32x32tiles, stored in 256x256 tileMap.
When the tiles are drawn, (this is a fast side scroller) the gap betwen the tiles can be seen, (fugly). The background is bright, tiles dark.

Also, the view is centred on the character, and when the character moves fast in one or other direction, (same sprite) I get this wierd
vertical scanline effect, depending on the speed of the charecter, the “scanlines” can be describes as fast moving highlighting lines. Or flicker.
Any ideas why this happens?

Every sprite is a quad.
THis is the GL init:

//Go into orthographic projection mode
            GL11.glMatrixMode(GL11.GL_PROJECTION);
            GL11.glLoadIdentity();
            GLU.gluOrtho2D(0.0f, (float)GAMEWIDTH, 0.0f, (float)GAMEHEIGHT);
            GL11.glMatrixMode(GL11.GL_MODELVIEW);
            GL11.glLoadIdentity();
            GL11.glViewport(0, 0, GAMEWIDTH,GAMEHEIGHT);
            
            //enable textures since we're going to use these for our sprites
            GL11.glEnable(GL11.GL_TEXTURE_2D);
            
            //disable the OpenGL depth test since we're rendering 2D graphics
            GL11.glDisable(GL11.GL_DEPTH_TEST);
            
            //Enable blending for OpenGL
            GL11.glEnable(GL11.GL_BLEND);
            GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA); 
            GL11.glTexEnvi(GL11.GL_TEXTURE_ENV, GL11.GL_TEXTURE_ENV_MODE, GL11.GL_MODULATE);
#2

AH!
First problem solved! Gah, spent 3 hours on the web looking for it, posted here, 10 minutes later, found solution.

Solution: load the textures as this:
GL11.glTexParameteri(target, GL11.GL_TEXTURE_MIN_FILTER,GL11.GL_NEAR);
GL11.glTexParameteri(target, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_NEAR);

However the second problem is still there!
This “flikering” when the player sprite is moving sideways, and the game is scrolling fast.

#3

GL11.GL_NEAR? Dont you mean GL11.GL_NEAREST and wrap? (Well, you can just use ints for the world-offset and the problem is solved.)

That flickering is most likely tearing. It also happens when moving vertically, but its less noticable then. Enabling vsync helps.

Fast scrolling… eh? Well, use some capping (see Display’s sync() methods).

#4

Yes, GL_NEAREST.

Enable vsync? Hmm, is that possible in windowed mode? And how do I do it? (Sorry for the stupid questions, but im learning.)

#5

Yes, it works in windowed mode.

Display.setVSyncEnabled(true);

Note that this is like asking for vsync. The driver can simply not allow it (if vsync is set to always off in the driver’s panel).