Develop Reference

LWJGL rendering nothing

I've looked over the following program over and over and cannot find why nothing renders to the screen when I run it:
Game.java:
public class Game {
private int fbid, fbid2;
public void start(){
DisplayManager.init();
glViewport(0, 0, DisplayManager.SCR_WIDTH, DisplayManager.SCR_HEIGHT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, 0, DisplayManager.SCR_WIDTH, DisplayManager.SCR_HEIGHT, 1, -1);
glMatrixMode(GL_MODELVIEW);
FloatBuffer fb = BufferUtils.createFloatBuffer(6);
fb.put(100).put(100).put(100).put(200).put(200).put(200);
fb.flip();
fbid = glGenBuffers();
glBindBuffer(GL_ARRAY_BUFFER, fbid);
glBufferData(GL_ARRAY_BUFFER, fb, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
FloatBuffer fb2 = BufferUtils.createFloatBuffer(9);
fb2.put(1).put(1).put(1).put(1).put(1).put(1).put(1).put(1).put(1);
fb2.flip();
fbid2 = glGenBuffers();
glBindBuffer(GL_ARRAY_BUFFER, fbid2);
glBufferData(GL_ARRAY_BUFFER, fb2, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
while(!DisplayManager.shouldClose()){
render();
}
DisplayManager.destroy();
}
public void render(){
glClear(GL_COLOR_BUFFER_BIT);
glClearColor(0, 0, 0, 0);
glColor3f(1, 1, 1);
glEnableClientState(GL_VERTEX_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, fbid);
glVertexPointer(2, GL_FLOAT, 0, 0);
glEnableClientState(GL_COLOR_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, fbid2);
glColorPointer(3, GL_FLOAT, 0, 0);
glDrawArrays(GL_TRIANGLES, 0, 3);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_COLOR_ARRAY);
DisplayManager.update();
}
}
DisplayManager.java:
public class DisplayManager {
public static final int SCR_WIDTH = 640;
public static final int SCR_HEIGHT = 480;
public static final int FPS = 30;
public static void init(){
try {
Display.setDisplayMode(new DisplayMode(SCR_WIDTH, SCR_HEIGHT));
Display.setTitle("StepBattler");
Display.setResizable(false);
Display.create();
} catch (LWJGLException e) {
e.printStackTrace();
Display.destroy();
System.exit(1);
}
}
public static void update(){
Display.update();
Display.sync(FPS);
}
public static void destroy(){
Display.destroy();
System.exit(0);
}
public static boolean shouldClose(){
return Display.isCloseRequested();
}
public static boolean shouldResize(){
return Display.wasResized();
}
}
When I run the screen, I just get a window filled with black, and I cannot understand why a white triangle won't render to the window. I've messed around with glClearColor(), and changing its values does succeed in changing the window background color, but I can't make a white triangle appear in the window. Also, I tried using glBegin()...glEnd() to render in immediate mode, with none of the code having to do with buffers in there, and it still didn't render anything. I'm really confused about this, what am I missing?

The arguments in you glOrtho() call look to be in the wrong order:
glOrtho(0, 0, DisplayManager.SCR_WIDTH, DisplayManager.SCR_HEIGHT, 1, -1);
The signature of glOrtho(), based on the man page, is:
void glOrtho(GLdouble left, GLdouble right,
GLdouble bottom, GLdouble top,
GLdouble nearVal, GLdouble farVal);
Since you're passing 0 for both left and right, the result would be an invalid projection matrix.
The correct call for your case is:
glOrtho(0, DisplayManager.SCR_WIDTH, 0, DisplayManager.SCR_HEIGHT, 1, -1);

OpenGL transparency not working

I am trying to draw my font texture atlas to the screen using LWJGL, but OpenGL instead draws a solid white square.
A working example using my drawing code:
import java.awt.image.*;
import java.io.*;
import java.nio.*;
import javax.imageio.*;
import org.lwjgl.*;
import org.lwjgl.opengl.*;
public class OpenGLImageTest
{
private static int textureID;
public static void main(String[] args) throws Exception
{
Display.setTitle("OpenGL Image Test");
Display.setDisplayMode(new DisplayMode(640, 480));
Display.create();
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GL11.glOrtho(0, 640, 0, 480, 1, -1);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
textureID = bindTextureFile("textures/font.png");
while(!Display.isCloseRequested())
{
Display.sync(60);
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
GL11.glClearColor(0, 0, 0, 1);
GL11.glColor4f(1, 0, 0, 1);
drawFontAtlas(0, 0);
Display.update();
}
Display.destroy();
}
private static void drawFontAtlas(int x, int y)
{
GL11.glPushMatrix();
GL11.glTranslatef(x, y, 0);
GL11.glDisable(GL11.GL_DEPTH_TEST);
GL11.glEnable(GL11.GL_TEXTURE_2D);
GL11.glEnable(GL11.GL_BLEND);
GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
GL11.glBindTexture(GL11.GL_TEXTURE_2D, textureID);
GL11.glBegin(GL11.GL_QUADS);
GL11.glVertex2i(0, 0);
GL11.glVertex2i(0, 256);
GL11.glVertex2i(256, 256);
GL11.glVertex2i(256, 0);
GL11.glEnd();
GL11.glDisable(GL11.GL_BLEND);
GL11.glDisable(GL11.GL_TEXTURE_2D);
GL11.glEnable(GL11.GL_DEPTH_TEST);
GL11.glPopMatrix();
}
private static int bindTextureFile(String file)
{
try
{
BufferedImage image = ImageIO.read(new FileInputStream(file));
int[] pixels = new int[image.getWidth() * image.getHeight()];
image.getRGB(0, 0, image.getWidth(), image.getHeight(), pixels, 0, image.getWidth());
ByteBuffer buffer = BufferUtils.createByteBuffer(image.getWidth() * image.getHeight() * 4);
for(int y = 0; y < image.getWidth(); y++)
{
for(int x = 0; x < image.getHeight(); x++)
{
int pixel = pixels[y * image.getWidth() + x];
buffer.put((byte)((pixel >> 16) & 0xFF));
buffer.put((byte)((pixel >> 8) & 0xFF));
buffer.put((byte)(pixel & 0xFF));
buffer.put((byte)((pixel >> 24) & 0xFF));
}
}
buffer.flip();
int textureID = GL11.glGenTextures();
GL11.glBindTexture(GL11.GL_TEXTURE_2D, textureID);
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, GL12.GL_CLAMP_TO_EDGE);
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_T, GL12.GL_CLAMP_TO_EDGE);
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_NEAREST);
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_NEAREST);
GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGB8, image.getWidth(), image.getHeight(), 0, GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, buffer);
return textureID;
}
catch(Exception e)
{
e.printStackTrace();
}
return -1;
}
}
Can anyone tell me what I am doing wrong and how to fix it?
Edit: font.png is white on transparent white. It's the default Minecraft font for testing purposes.

Your problem can be fixed by adding texture coordinates:
{
GL11.glTexCoord2f(0, 1); // added texture coordinate
GL11.glVertex2i(0, 0);
GL11.glTexCoord2f(0, 0); // added texture coordinate
GL11.glVertex2i(0, 256);
GL11.glTexCoord2f(1, 0); // added texture coordinate
GL11.glVertex2i(256, 256);
GL11.glTexCoord2f(1, 1); // added texture coordinate
GL11.glVertex2i(256, 0);
}
I actually used slick-util.jar to load your texture, but it will work with your code just the same... you can find a working example of my code bellow... slick-util.jar can be found here
In order to get actual transparency, you also need to change this line in your code: GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGB8, image.getWidth(), image.getHeight(), 0, GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, buffer); and what needs to be changed is GL11.GL_RGB8 into GL11.GL_RGBA
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.opengl.GL11;
import org.newdawn.slick.opengl.Texture;
import org.newdawn.slick.opengl.TextureLoader;
public class OpenGLImageTest {
private static Texture tex; //private static int textureID;
public static void main(String[] args) throws Exception {
Display.setTitle("OpenGL Image Test");
Display.setDisplayMode(new DisplayMode(640, 480));
Display.create();
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GL11.glOrtho(0, 640, 0, 480, 1, -1);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
tex = loadTexture("textures/font.png"); //textureID = bindTextureFile("textures/font.png");
while (!Display.isCloseRequested()) {
Display.sync(60);
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
GL11.glClearColor(0, 0, 0, 1);
GL11.glColor4f(1, 1, 1, 1);
drawFontAtlas(0, 0);
Display.update();
}
Display.destroy();
}
private static void drawFontAtlas(int x, int y) {
GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
GL11.glPushMatrix();
GL11.glTranslatef(x, y, 0);
GL11.glDisable(GL11.GL_DEPTH_TEST);
GL11.glEnable(GL11.GL_TEXTURE_2D);
GL11.glEnable(GL11.GL_BLEND);
tex.bind(); //GL11.glBindTexture(GL11.GL_TEXTURE_2D, textureID);
GL11.glBegin(GL11.GL_QUADS);
{
GL11.glTexCoord2f(0, 1); // added texture coordinate
GL11.glVertex2i(0, 0);
GL11.glTexCoord2f(0, 0); // added texture coordinate
GL11.glVertex2i(0, 256);
GL11.glTexCoord2f(1, 0); // added texture coordinate
GL11.glVertex2i(256, 256);
GL11.glTexCoord2f(1, 1); // added texture coordinate
GL11.glVertex2i(256, 0);
}
GL11.glEnd();
GL11.glDisable(GL11.GL_BLEND);
GL11.glDisable(GL11.GL_TEXTURE_2D);
GL11.glEnable(GL11.GL_DEPTH_TEST);
GL11.glPopMatrix();
}
public static Texture loadTexture(String texturePath) {
try {
return TextureLoader.getTexture("png", new FileInputStream(new File(texturePath)));
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}

Can't draw to FrameBufferObject, then draw to frameBuffer, in LWJGL

My problem is that I have drawn a small quad to a Frame Buffer Object and am trying to draw it to the framebuffer on the window. This is my java code:
import static org.lwjgl.opengl.GL30.*;
import static org.lwjgl.opengl.GL11.*;
import java.nio.ByteBuffer;
import org.lwjgl.opengl.*;
public class Main
{
private static int fboID;
private static int texID;
private static int depthBuff;
public static void main(String[] args)
{
try
{
Display.setDisplayMode(new DisplayMode(640, 480));
Display.create();
} catch (Exception e)
{
e.printStackTrace();
System.exit(1);
}
glEnable(GL_TEXTURE_2D);
initFramebuffer();
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, 640, 480, 0, 1, -1);
glMatrixMode(GL_MODELVIEW);
while (!Display.isCloseRequested())
{
glBindTexture(GL_TEXTURE_2D, texID);
glBegin(GL_QUADS);
glTexCoord2f(0, 0);
glVertex2i(10, 10);
glTexCoord2f(0, 1);
glVertex2i(10, 470);
glTexCoord2f(1, 1);
glVertex2i(630, 470);
glTexCoord2f(1, 0);
glVertex2i(630, 10);
glEnd();
glBindTexture(GL_TEXTURE_2D, 0);
Display.update();
Display.sync(60);
}
}
public static void initFramebuffer()
{
fboID = glGenFramebuffers();
glBindFramebuffer(GL_FRAMEBUFFER, fboID);
texID = glGenTextures();
glBindTexture(GL_TEXTURE_2D, texID);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 640, 480, 0, GL_RGBA, GL_UNSIGNED_BYTE, (ByteBuffer) null);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
depthBuff = glGenRenderbuffers();
glBindRenderbuffer(GL_RENDERBUFFER, depthBuff);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, 640, 480);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthBuff);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texID, 0);
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
System.out.println("GOD DAMT");
glBindFramebuffer(GL_FRAMEBUFFER, fboID);
{
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, 640, 480, 0, 1, -1);
glMatrixMode(GL_MODELVIEW);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glViewport(0, 0, 640, 480);
//glLoadIdentity();
glBegin(GL_QUADS);
glColor3f(1, 0, 0);
glVertex2i(0, 0);
glVertex2i(100, 0);
glVertex2i(100, 100);
glVertex2i(0, 100);
glEnd();
}
glBindFramebuffer(GL_FRAMEBUFFER, 0);
}
}
Whenever I run this code I get nothing but a black screen.
What am I doing wrong?

I'm not tooooo familar with OpenGL but
Instead of
glEnable(GL_TEXTURE_2D);
initFramebuffer();
you should set texturing enabled after initializing fb:
initFramebuffer();
glEnable(GL_TEXTURE_2D);
this is caused by glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); which seems to render uninitialized (non-fb texture) in front of your fb texture box, which causes blank screen

Java LWJGL: When I call "GL11.glEnd" the polygon disappears?

When I call "GL11.glEnd" the polygon disappears. If I leave that one line "GL11.glEnd" out, then it stays on the screen, but when I put it in, the polygon I was drawing disappears.
package package01;
import org.lwjgl.opengl.GL11;
public class Graph {
...
void initGraph(){
GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
GL11.glClearDepth(1.0);
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
GL11.glOrtho(-500, 500, -281, 281, -1, 1);
GL11.glColor3f(0.8f, 0.8f, 1.0f);
GL11.glBegin(GL11.GL_POLYGON);
GL11.glVertex3f(-60, 110, 0);
GL11.glVertex3f(60, 110, 0);
GL11.glVertex3f(120, 0, 0);
GL11.glVertex3f(60, -110, 0);
GL11.glVertex3f(-60, -110, 0);
GL11.glVertex3f(-120, 0, 0);
GL11.glEnd();
GL11.glFlush();
}
}
And here is the second class if it would help.
package package01;
...
public class DisplayScreen {
Graph g = new Graph();
void start(){
try {
Display.setDisplayMode(new DisplayMode(1000,562));
Display.create();
GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
} catch(LWJGLException e) {
e.printStackTrace();
}
while(!Display.isCloseRequested()){
Display.update();
g.initGraph();
}
Display.destroy();
}
public static void main(String[] args){
DisplayScreen ds = new DisplayScreen();
ds.start();
}
}

remove GL11.glOrtho(-500, 500, -281, 281, -1, 1); from the initGraph() method.
add
glMatrixMode(GL11.GL_PROJECTION);
glLoadIdentity();
GL11.glOrtho(-500, 500, -281, 281, -1, 1);
glMatrixMode(GL11.GL_MODELVIEW);
before the game loop.
update needs to be called after initGraph
g.initGraph();
Display.update();

opengl textures not rendering correctly

The problem i am encountering is that i cannot get my texture to render in the correct proportions and for some reason the texture is also repeating itself with a space inbetween.
this is the texture im using(i am trzing to fill the screen with this texture):
When rendered it looks like this(red outline is the entire screen and texture is rendered with a 1 px border):
and here is the code:
package game;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import org.lwjgl.input.Keyboard;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.opengl.GL11;
import org.lwjgl.util.Timer;
import org.lwjgl.util.glu.GLU;
import org.newdawn.slick.opengl.TextureLoader;
public class WarZone {
private boolean done = false;
private String windowTitle = "War Zone";
private DisplayMode displayMode;
private Timer timer;
private float dt;
public static void main(String[] args) {
new WarZone().run(false);
}
public void run(boolean fullscreen) {
try {
init();
switchToOrtho();
while (!done) {
timer.tick();
update();
render();
Display.update();
}
cleanup();
} catch (Exception e) {
e.printStackTrace();
System.exit(0);
}
}
private void update() {
// Exit if Escape is pressed or window is closed
if (Keyboard.isKeyDown(Keyboard.KEY_ESCAPE) || Display.isCloseRequested()) {
done = true;
return;
}
}
private boolean render() {
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT); // Clear the screen and the depth buffer
GL11.glLoadIdentity(); // Reset the current modelview matrix
int w = displayMode.getWidth();
int h = displayMode.getHeight();
GL11.glColor3f(1, 0, 0);
GL11.glBindTexture(GL11.GL_TEXTURE_2D, 0);
GL11.glBegin(GL11.GL_QUADS);
GL11.glVertex2i(0, 0);
GL11.glVertex2i(w, 0);
GL11.glVertex2i(w, h);
GL11.glVertex2i(0, h);
GL11.glEnd();
//if(true)return false;
GL11.glColor3f(0, 1, 1);
GL11.glBindTexture(GL11.GL_TEXTURE_2D, 1);
GL11.glBegin(GL11.GL_QUADS);
GL11.glTexCoord2f(0, 0);
GL11.glVertex2i(1, 1);
GL11.glTexCoord2f(1, 0);
GL11.glVertex2i(w - 1, 1);
GL11.glTexCoord2f(1, 1);
GL11.glVertex2i(w - 1, h - 1);
GL11.glTexCoord2f(0, 1);
GL11.glVertex2i(1, h - 1);
GL11.glEnd();
return true; // Rendered correctly
}
public static void switchToOrtho() {
GL11.glDisable(GL11.GL_DEPTH_TEST);
GL11.glDisable(GL11.GL_LIGHTING);
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glPushMatrix();
GL11.glLoadIdentity();
GL11.glOrtho(0, Display.getDisplayMode().getWidth(), 0, Display.getDisplayMode().getHeight(), -1, 1);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glLoadIdentity();
}
public static void switchToFrustum() {
GL11.glEnable(GL11.GL_DEPTH_TEST);
GL11.glEnable(GL11.GL_LIGHTING);
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glPopMatrix();
GL11.glMatrixMode(GL11.GL_MODELVIEW);
}
private void init() throws Exception {
createWindow();
initGL();
load();
}
private void load() throws FileNotFoundException, IOException {
TextureLoader.getTexture("BMP", new FileInputStream("res/temp/Main_Menu_Play_Button.bmp"), true).getTextureID();
}
private void createWindow() throws Exception {
DisplayMode availibleDisplayModes[] = Display.getAvailableDisplayModes();
for (DisplayMode d:availibleDisplayModes) {
if (d.getWidth() == 640 && d.getHeight() == 480 && d.getBitsPerPixel() == 32) {
displayMode = d;
break;
}
}
Display.setDisplayMode(displayMode);
Display.setTitle(windowTitle);
Display.create();
}
private void initGL() {
GL11.glEnable(GL11.GL_TEXTURE_2D); // Enable texture mapping
GL11.glShadeModel(GL11.GL_SMOOTH); // Enable smooth shading
GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // Black background
GL11.glClearDepth(1.0f); // Depth buffer setup
GL11.glEnable(GL11.GL_DEPTH_TEST); // Enables depth testing
GL11.glDepthFunc(GL11.GL_LEQUAL); // Type of depth testing
GL11.glMatrixMode(GL11.GL_PROJECTION); // Select projection matrix
GL11.glLoadIdentity(); // Reset the projection matrix
// Calculate the aspect ratio of the window
GLU.gluPerspective(45.0f, (float)displayMode.getWidth() / (float)displayMode.getHeight(), 0.1f, 100.0f);
GL11.glMatrixMode(GL11.GL_MODELVIEW);// Select the modelview matrix
GL11.glHint(GL11.GL_PERSPECTIVE_CORRECTION_HINT, GL11.GL_NICEST);// Most precise perspective calculations
}
public void requestFinish() {
done = true;
}
private void cleanup() {
Display.destroy();
}
}
I would reallz appreciate it if someone could tell me what i had done wrong.

First, I don't know what TextureLoader or newdawn.slick.opengl are, so there is only limited information I can give about this.
However, it is very possible that your texture loading code does not know how to handle non-power-of-two textures. Which means it is likely padding the texture's size out to the nearest power of two.
More importantly is this:
GL11.glColor3f(0, 1, 1);
GL11.glBindTexture(GL11.GL_TEXTURE_2D, 1);
GL11.glBegin(GL11.GL_QUADS);
GL11.glTexCoord2f(0, 0);
GL11.glVertex2i(1, 1);
GL11.glTexCoord2f(1, 0);
GL11.glVertex2i(w - 1, 1);
GL11.glTexCoord2f(1, 1);
GL11.glVertex2i(w - 1, h - 1);
GL11.glTexCoord2f(0, 1);
GL11.glVertex2i(1, h - 1);
GL11.glEnd();
This will draw a screen-sized quad (assuming that w and h are screen sizes). This quad maps the entire area of the texture to this quad. OpenGL is only doing what you told it to do: take the texture and map it to the quad.
If you want to draw a texture with pixel accuracy (1:1 texel to pixel), then you need to provide a width and height to the vertex positions that is equal to the texture's size, not the screen size.
Also, you set the color to (0, 1, 1). The default texture environment will multiply the per-vertex color by the texel values fetched from the texture. So you should either set the color to white, or change the texture environment.

OpenGL Doesn't like textures that are not powers of two if I recall. Is your texture a power of 2 for both height and width?
http://www.gamedev.net/topic/466904-opengl-textures-only-power-of-two/