平鋪貼圖OpenGL C++

Question

我試圖用openGL和C++實現tile mapping。

我發現this 教程/解釋，我認爲很不錯。

當我編譯並運行visual studio 2010中的代碼時，它只是打開一個窗口並顯示一個白色正方形。

也許我的文件加載不正確。我已經嘗試了網站使用的.raw文件以及我自己的.png文件。

#include <GL/gl.h> 
#include <GL/glut.h> 
#include <windows.h> 
#include <stdio.h> 

GLuint texture; //the array for our texture 
GLuint texture2; //the array for our second texture 

int cMap[10][10] = { //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}, 
}; 

//function to load the RAW file 

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 display (void) { 
    glClearColor (0.0,0.0,0.0,1.0); 
    glClear (GL_COLOR_BUFFER_BIT); 
    glLoadIdentity(); 
    glEnable(GL_TEXTURE_2D); 
    glTranslatef(-5, 4, -20); //translate back a bit to view the map correctly 

    drawTiles(); //draw our tiles 
    glutSwapBuffers(); 
} 
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 main (int argc, char **argv) { 
    glutInit (&argc, argv); 
    glutInitDisplayMode (GLUT_DOUBLE); 
    glutInitWindowSize (500, 500); 
    glutInitWindowPosition (100, 100); 
    glutCreateWindow (「A basic OpenGL Window「); 
    glutDisplayFunc (display); 
    glutIdleFunc (display); 
    glutReshapeFunc (reshape); 

    //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; 
} 

Answer 1

確保您的working directory就是您認爲的那樣。

或使用絕對文件名。

否則fopen()將失敗，因爲它無法找到該文件。