I am trying to texture a quad using opengl and c++.here is the code I am using.
<code>
#include <iostream>
#include <stdlib.h>
#include "glut.h" // OpenGL toolkit
#include "GL/gl.h"
#include "GL/glu.h"
#include <windows.h>
#include <stdio.h>
#include "GLAux.h"
GLuint texture[1];
AUX_RGBImageRec *LoadBMP(char *Filename)
{
FILE *File=NULL;
if(!Filename)
{
return NULL;
}
File=fopen(Filename,"r");
if(File)
{
fclose(File);
return auxDIBImageLoad(Filename);
}
return NULL;
}
int LoadGLTextures()
{
int Status=FALSE;
AUX_RGBImageRec *TextureImage[1];
memset(TextureImage,0,sizeof(void *)*1);
if(TextureImage[0]=LoadBMP("image1.bmp"))
{
Status=TRUE;
glGenTextures(1,&texture[0]);
glBindTexture(GL_TEXTURE_2D,texture[0]);
glTexImage2D(GL_TEXTURE_2D,0,3,TextureImage[0]->sizeX,TextureImage[0]->sizeY,0,GL_RGB,GL_UNSIGNED_BYTE,TextureImage[0]->data);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
}
if(TextureImage[0])
{
if(TextureImage[0]->data)
{
free(TextureImage[0]->data);
}
free(TextureImage[0]);
}
return Status;
}
int InitGL(GLvoid)
{
if(!LoadGLTextures())
{
return FALSE;
}
glEnable(GL_TEXTURE_2D);
glShadeModel(GL_SMOOTH);
glClearColor(0.0f,0.0f,0.0f,0.0f);
glEnable(GL_DEPTH_TEST);
glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST);
return TRUE;
}
GLfloat left = 0.0f;
GLfloat right = 0.0f;
// Initial square position and size
GLfloat x = 50.0f;
GLfloat y = 0.0f;
GLfloat rsize = 5;
// Step size in x and y directions
// (number of pixels to move each time)
GLfloat xstep = 5.0f;
GLfloat ystep = 5.0f;
// Keep track of windows changing width and height
GLfloat windowWidth;
GLfloat windowHeight;
//////////////////////////////////////////////////////////
// Called to draw scene
void RenderScene(void)
{
// Clear the window with current clearing color
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glBindTexture(GL_TEXTURE_2D,texture[0]);
glBegin(GL_QUADS);
glTexCoord2f(0.0,0.0);
glVertex2f(0.0,0.0);
glTexCoord2f(1.0,0.0);
glVertex2f(50.0,0.0);
glTexCoord2f(1.0,1.0);
glVertex2f(50.0,50.0);
glTexCoord2f(0.0,1.0);
glVertex2f(0.0,50.0);
glEnd();
// Set current drawing color to red
// R G B
glColor3f(1.0f, 0.0f, 0.0f);
glRectf(-135.0f,75.0f,-85.0f,65.0f);
glRectf(-95.0f,100.0f,-85.0f,75.0f);
glRectf(-125.0f,55.0f,-95.0f,45.0f);
glColor3f(0.0f, 1.0f, 0.0f);
glRectf(135.0f,75.0f,85.0f,65.0f);
glRectf(95.0f,100.0f,85.0f,75.0f);
glColor3f(0.0f, 0.0f, 1.0f);
glRectf(135.0f,-75.0f,85.0f,-65.0f);
glRectf(95.0f,-100.0f,85.0f,-75.0f);
glColor3f(1.0f, 0.0f, 1.0f);
glRectf(-135.0f,-75.0f,-85.0f,-65.0f);
glRectf(-95.0f,-100.0f,-85.0f,-75.0f);
glColor3f(1.0f, 1.0f, 1.0f);
// Draw a filled rectangle with current color
glRectf(x, y, x + rsize, y - rsize);
// Flush drawing commands and swap
glutSwapBuffers();
}
///////////////////////////////////////////////////////////
// Called by GLUT library when idle (window not being
// resized or moved)
void TimerFunction(int value)
{
// Reverse direction when you reach left or right edge
if(x > windowWidth-rsize || x < -windowWidth)
xstep = -xstep;
// Reverse direction when you reach top or bottom edge
if(y > windowHeight || y < -windowHeight + rsize)
ystep = -ystep;
if(y >= 60 && x >= -135 && x <= -85)
{
ystep = -ystep;
}
if(y >= 60 && x >= -135 && x <= -80)
{
xstep = -xstep;
}
if(y >= 60 && x <= 135 && x >= 80)
{
ystep = -ystep;
}
if(y >= 60 && x <= 135 && x >= 80)
{
xstep = -xstep;
}
if(y <= -60 && x >= -135 && x <= -85)
{
ystep = -ystep;
}
if(y <= -60 && x >= -135 && x <= -85)
{
xstep = -xstep;
}
if(y <= -60 && x <= 135 && x >= 85)
{
ystep = -ystep;
}
if(y <= -60 && x <= 135 && x >= 85)
{
xstep = -xstep;
}
// Actually move the square
x += xstep;
y += ystep;
// Check bounds. This is in case the window is made
// smaller while the rectangle is bouncing and the
// rectangle suddenly finds itself outside the new
// clipping volume
if(x > (windowWidth-rsize + xstep))
x = windowWidth-rsize-1;
else if(x < -(windowWidth + xstep))
x = -windowWidth -1;
if(y > (windowHeight + ystep))
y = windowHeight-1;
else if(y < -(windowHeight - rsize + ystep))
y = -windowHeight + rsize - 1;
// Redraw the scene with new coordinates
glutPostRedisplay();
glutTimerFunc(33,TimerFunction, 1);
}
///////////////////////////////////////////////////////////
// Setup the rendering state
void SetupRC(void)
{
// Set clear color to blue
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
}
///////////////////////////////////////////////////////////
// Called by GLUT library when the window has chanaged size
void ChangeSize(int w, int h)
{
GLfloat aspectRatio;
// Prevent a divide by zero
if(h == 0)
h = 1;
// Set Viewport to window dimensions
glViewport(0, 0, w, h);
// Reset coordinate system
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// Establish clipping volume (left, right, bottom, top, near, far)
aspectRatio = (GLfloat)w / (GLfloat)h;
if (w <= h)
{
windowWidth = 100;
windowHeight = 100 / aspectRatio;
glOrtho (-100.0, 100.0, -windowHeight, windowHeight, 1.0, -1.0);
}
else
{
windowWidth = 100 * aspectRatio;
windowHeight = 100;
glOrtho (-windowWidth, windowWidth, -100.0, 100.0, 1.0, -1.0);
}
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
void PaddleLeft()
{
// glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glColor3f(1.0f,0.0f,0.0f);
glRectf(-125.0f-left,55.0f,-95.0f-left,45.0f);
glutSwapBuffers();
left+=1.0f;
}
void PaddleRight()
{
}
void keyboard(unsigned char key, int x, int y)
{
switch(key)
{
case 27:
{
exit(0);
break;
}
}
}
void mySpecialKeys(int key, int x, int y)
{
switch(key)
{
case GLUT_KEY_LEFT:
PaddleLeft();
break;
case GLUT_KEY_RIGHT:
PaddleRight();
break;
}
}
///////////////////////////////////////////////////////////
// Main program entry point
int main(int argc, char* argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);
glutInitWindowPosition(300,100);
glutInitWindowSize(800,600);
glutCreateWindow("Warlords");
glutDisplayFunc(RenderScene);
AUX_RGBImageRec *LoadBMP(char *Filename);
int InitGL(GLvoid);
int LoadGLTextures();
glutReshapeFunc(ChangeSize);
glutKeyboardFunc(keyboard);
glutSpecialFunc(mySpecialKeys);
glutTimerFunc(33, TimerFunction, 1);
SetupRC();
glutMainLoop();
return 0;
}
</code>
