I am new to OpenGL. I have the following code that I am using from a tutorial I followed, what it does is render a tile map. It does this successfully but my problem now is that I want to add a moveable object onto the window however it is not appearing.
#include "stdafx.h"
#include <string>
#include <windows.h>
#include <iostream>
#include <conio.h>
#include <sstream>
#include <math.h>
#include <gl\gl.h>
#include <gl\glu.h>
#include "GL/freeglut.h"
#pragma comment(lib, "OpenGL32.lib")
// window size and update rate (60 fps)
int width = 700;
int height = 700;
int interval = 1000 / 60;
// ball
float ball_pos_x = width / 2;
float ball_pos_y = height / 2;
float ball_dir_x = -1.0f;
float ball_dir_y = 0.0f;
int ball_width = 20;
int ball_height = 20;
int ball_speed = 5;
GLuint texture; //the array for our texture
GLuint texture2; //the array for our second texture
void keyboard() {
if (GetAsyncKeyState(VK_LEFT)) ball_pos_x -= ball_speed;
if (GetAsyncKeyState(VK_RIGHT)) ball_pos_x += ball_speed;
if (GetAsyncKeyState(VK_UP)) ball_pos_y += ball_speed;
if (GetAsyncKeyState(VK_DOWN)) ball_pos_y -= ball_speed;
}
int cMap[30][30] = { //our map
{1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
{1, 0, 1, 0, 0, 0, 0, 0, 0, 1},
{1, 0, 1, 0, 0, 0, 0, 0, 0, 1},
{1, 0, 1, 0, 0, 0, 0, 0, 0, 1},
{1, 0, 1, 0, 0, 0, 0, 0, 0, 1},
{1, 0, 1, 1, 1, 1, 1, 1, 1, 1},
{1, 0, 0, 0, 0, 0, 0, 0, 0, 1},
{1, 0, 0, 0, 0, 0, 0, 0, 0, 1},
{1, 0, 0, 0, 0, 0, 0, 0, 0, 1},
{1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
};
void drawRect(float x, float y, float width, float height) {
glBegin(GL_QUADS);
glVertex2f(x, y);
glVertex2f(x + width, y);
glVertex2f(x + width, y + height);
glVertex2f(x, y + height);
glEnd();
}
GLuint LoadTexture( const char * filename, int width, int height )
{
GLuint texture;
unsigned char * data;
FILE * file;
//The following code will read in our RAW file
file = fopen( filename, "rb" );
if ( file == NULL ) return 0;
data = (unsigned char *)malloc( width * height * 3 );
fread( data, width * height * 3, 1, file );
fclose( file );
glGenTextures( 1, &texture );
glBindTexture( GL_TEXTURE_2D, texture );
glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,
GL_MODULATE ); //set texture environment parameters
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
GL_LINEAR );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
GL_LINEAR );
//Here we are setting the parameter to repeat the texture
//instead of clamping the texture
//to the edge of our shape.
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,
GL_REPEAT );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,
GL_REPEAT );
//Generate the texture
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0,
GL_RGB, GL_UNSIGNED_BYTE, data);
free( data ); //free the texture
return texture; //return whether it was successfull
}
void FreeTexture( GLuint texture )
{
glDeleteTextures( 1, &texture );
}
void drawTiles (void) { //our function to draw the tiles
for (int i = 0; i < 10; i++) //loop through the height of the map
{
for (int j = 0; j < 10; j++) //loop through the width of the map
{
if (cMap[i][j] == 0) //if the map at this position contains a 0
{
glBindTexture( GL_TEXTURE_2D, texture ); //bind our grass texture to our shape
}
else //otherwise
{
glBindTexture( GL_TEXTURE_2D, texture2 ); //bind our dirt texture to our shape
}
glPushMatrix(); //push the matrix so that our translations only affect this tile
glTranslatef(j, -i, 0); //translate the tile to where it should belong
glBegin (GL_QUADS); //begin drawing our quads
glTexCoord2d(0.0, 0.0);
glVertex3f(0.0, 0.0, 0.0); //with our vertices we have to assign a texcoord
glTexCoord2d(1.0, 0.0);
glVertex3f(1.0, 0.0, 0.0); //so that our texture has some points to draw to
glTexCoord2d(1.0, 1.0);
glVertex3f(1.0, 1.0, 0.0);
glTexCoord2d(0.0, 1.0);
glVertex3f(0.0, 1.0, 0.0);
glEnd();
glPopMatrix(); //pop the matrix
} //end first loop
} //end second loop
}
void draw() {
// clear (has to be done at the beginning)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity(); // ToDo: draw our scene
// draw ball
drawRect(ball_pos_x - ball_width / 2, ball_pos_y - ball_height / 2, ball_width, ball_height);
glEnable( GL_TEXTURE_2D );
glTranslatef(-5, 4, -20); //translate back a bit to view the map correctly
drawTiles(); //draw our tiles
// swap buffers (has to be done at the end)
glutSwapBuffers();
}
void UpdatePlayer(){
// hit by right racket?
if (ball_pos_x < ball_pos_x + ball_width &&
ball_pos_x > enemy_pos_x &&
ball_pos_y < enemy_pos_y + enemy_height &&
ball_pos_y > enemy_pos_y) {
ball_pos_x = ball_pos_x;
ball_pos_y = ball_pos_y;
}
}
void update(int value) { // Call update() again in 'interval' milliseconds
// input handling
keyboard();
UpdatePlayer();
glutTimerFunc(interval, update, 0);
// Redisplay frame
glutPostRedisplay();
}
void enable2D(int width, int height) {
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0f, width, 0.0f, height, 0.0f, 1.0f);
glMatrixMode (GL_MODELVIEW);
glLoadIdentity();
}
void reshape (int w, int h) {
glViewport (0, 0, (GLsizei)w, (GLsizei)h);
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
gluPerspective (60, (GLfloat)w / (GLfloat)h, 1.0, 100.0);
glMatrixMode (GL_MODELVIEW);
}
int _tmain(int argc, char** argv)
{
// initialize opengl (via glut)
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(width, height); glutCreateWindow("noobtuts.com Pong");
// Register callback functions
glutDisplayFunc(draw);
glutIdleFunc (draw);
glutReshapeFunc (reshape);
glutTimerFunc(interval, update, 0);
// setup scene to 2d mode and set draw color to white
enable2D(width, height);
glColor3f(1.0f, 1.0f, 1.0f);
//Load our texture
texture = LoadTexture("texture.raw", 256, 256);
texture2 = LoadTexture("texture2.raw", 256, 256);
glutMainLoop ();
//Free our texture
FreeTexture(texture);
FreeTexture(texture2);
return 0;
}
If I was to comment out in the main...
glutIdleFunc (draw);
glutReshapeFunc (reshape);
The tile map will disappear and my moveable square is visible and works...I just can't implement the two together successfully. Again i'm completely new to this so apologise if I am doing something really stupid Any ideas where I am going wrong?
