Textures not rendering with VBOs

Question

After having used display lists for my programs since I started learning OpenGL, I've finally decided to switch to VBOs after experiencing a considerable amount of lag when I started work on a new game. I've nearly finished with my transition, but I'm still having a bit of trouble with rendering the textures to the screen. The way I'm working it is this: I have several sprites of the same dimensions for each type of "block" in the game (it's a Terraria port) which are loaded into the game via a convenience method, then after they're all loaded, they're compiled into a virtual texture atlas via Graphics2D, converted to a Slick texture, and their relative coordinates are saved to a HashMap. However, when it comes time to grab the textures out of the HashMap and render them, the game simply doesn't. Here's part of my code for adding a block to the VBO (this is executed 4 times per block, once for each corner):

// top left
// vertex
values.add(Float.valueOf((float)b.getLocation().getPixelX()));
values.add(Float.valueOf((float)b.getLocation().getPixelY()));
// light
values.add(Float.valueOf((float)b.getLightLevel() / 15));
values.add(Float.valueOf((float)b.getLightLevel() / 15));
values.add(Float.valueOf((float)b.getLightLevel() / 15));
// texture
values.add(tX);
values.add(tY);

(Note: values is a list which is later converted to an array.) Then comes my code for rendering the VBO:

public static void render(){
    glPushMatrix();
    glTranslatef(MineFlat.xOffset, MineFlat.yOffset, 0);
    glBindTexture(GL_TEXTURE_2D, BlockUtil.atlas.getTextureID());
    glVertexPointer(2, GL_FLOAT, 28, 0);
    glColorPointer(3, GL_FLOAT, 28, 8);
    glTexCoordPointer(2, GL_FLOAT, 28, 20);
    glDrawArrays(GL_QUADS, 0, vertexArray.length / 7);
    glBindTexture(GL_TEXTURE_2D, 0);
    glPopMatrix();
}

The blocks are properly rendered with the correct lighting, but they lack any sort of texture. Any suggestions as to how to get the code working? I apologize if the answer is obvious, but I still consider myself a bit of an OpenGL noob, especially in the area of VBOs.

One last thing; I should mention that I'm not using any shaders in my current game.

EDIT: I seem to be a bit mistaken. Upon experimenting with the code by manually setting all texture coords, I discovered that the game simply converts the texture to a uniform color by averaging the RGB value of all pixels. I didn't recognize this before because the color of most blocks is grey. I recall having this problem before with display lists, but that was quite a while ago, and so I don't remember how I resolved it.

SECOND EDIT: Screenshots of the expected and actual result, respectively: https://i.stack.imgur.com/3t4r4.png https://i.stack.imgur.com/edv8v.png

Answer 1

I figured out my problem myself, and found it was due to a very simple mistake: I added a red pixel to the top left corner of one texture, and discovered it was the only one being rendered. I got the idea from this thread. It's because I forgot to cast the image width to a float, so when divided by 16, it would yield zero.