问题
Im trying to texture the bottom part of a level but for some reason the code cant find my bmp file, the bmp file is in the same folder as my code so im wondering if its an issue with my code, any help would be great
#include windows.h
#include gl\gl.h
#include glut.h
#include stdlib.h
#include iostream
void init(void);
void display(void);
void keyboard(unsigned char, int, int);
void resize(int, int);
void drawcube(float, float, float, float, float, float, int);
#define ROAD 0
struct Image
{
unsigned long size_x;
unsigned long size_y;
char *data;
};
typedef struct Image Image;
const int textureCount = 1;
Image myTextureData[textureCount];
GLuint theTexture[textureCount];
char* textureFilenames[textureCount] = {"road.bmp"};
int is_depth;
int main (int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
glutInitWindowSize(600, 600);
glutInitWindowPosition(40, 40);
glutCreateWindow("3D World");
init();
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutReshapeFunc(resize);
glEnable(GL_TEXTURE_2D);
glutMainLoop();
return 0;
}
void init(void)
{
glClearColor(0.0, 0.0, 0.0, 0.0);
glEnable(GL_DEPTH_TEST);
glMatrixMode(GL_MODELVIEW);
is_depth = 1;
}
int imageLoader(const char *filename, Image *image)
{
FILE *file;
unsigned long size;
unsigned long i;
unsigned short int planes;
unsigned short int bpp;
char temp;
char finalName[80];
glTexCoord2f(1.0, 0.0);
strcpy(finalName, "" );
strcat(finalName, filename);
if ((file = fopen(finalName, "rb"))==NULL)
{
printf("File Not Found : %s\n",finalName);
return 0;
}
fseek(file, 18, SEEK_CUR);
glTexCoord2f(1.0, 0.0);
if ((i = fread(&image->size_x, 4, 1, file)) != 1)
{
printf("Error reading width from %s.\n", finalName);
return 0;
}
if ((i = fread(&image->size_y, 4, 1, file)) != 1)
{
printf("Error reading height from %s.\n", finalName);
return 0;
}
size = image->size_x * image->size_y * 3;
if ((fread(&planes, 2, 1, file)) != 1)
{
printf("Error reading planes from %s.\n", finalName);
return 0;
}
if (planes != 1)
{
printf("Planes from %s is not 1: %u\n", finalName, planes);
return 0;
}
if ((i = fread(&bpp, 2, 1, file)) != 1)
{
printf("Error reading bpp from %s.\n", finalName);
return 0;
}
if (bpp != 24)
{
printf("Bpp from %s is not 24: %u\n", finalName, bpp);
return 0;
}
fseek(file, 24, SEEK_CUR);
image->data = (char *) malloc(size);
if (image->data == NULL)
{
printf("Error allocating memory for color-corrected image data");
return 0;
}
if ((i = fread(image->data, size, 1, file)) != 1)
{
printf("Error reading image data from %s.\n", finalName);
return 0;
}
for (i=0;i<size;i+=3)
{
temp = image->data[i];
image->data[i] = image->data[i+2];
image->data[i+2] = temp;
}
return 1;
}
void textureLoader()
{
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
for(int k=0; k < textureCount; k++)
{
if(!imageLoader(textureFilenames[k], &myTextureData[k]))
exit(1);
glGenTextures(1, &theTexture[k]);
glBindTexture(GL_TEXTURE_2D, theTexture[k]);
glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST);
gluBuild2DMipmaps(GL_TEXTURE_2D, 3, myTextureData[k].size_x, myTextureData[k].size_y, GL_RGB, GL_UNSIGNED_BYTE, myTextureData[k].data);
}
}
void display(void)
{
if (is_depth)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
else
glClear(GL_COLOR_BUFFER_BIT);
textureLoader();
glBegin(GL_QUADS);
glTexCoord2f(0.0,0.0);
glVertex3f(-75.0, 0.0, -400.0);
glTexCoord2f(0.0,1.0);
glVertex3f(-75.0, 0.0, 100.0);
glTexCoord2f(1.0,1.0);
glVertex3f(75.0, 0.0, 100.0);
glTexCoord2f(1.0,1.0);
glVertex3f(75.0, 0.0, -400.0);
drawcube(-70,15,72,8,15,28,0);
drawcube(-70,10,10,8,10,28,0);
drawcube(-70,15,-45,8,15,18,0);
drawcube(-70,15,-85,8,15,18,0);
drawcube(-70,35,-125,8,35,12,0);
drawcube(-70,9,-170,8,9,28,0);
drawcube(-70,15,-220,8,15,18,0);
drawcube(-70,15,-265,8,15,28,0);
drawcube(-70,15,-330,8,15,28,0);
drawcube(67,15,72,8,15,28,0);
drawcube(67,10,10,8,10,28,0);
drawcube(67,15,-45,8,15,18,0);
drawcube(67,15,-85,8,15,18,0);
drawcube(67,35,-125,8,35,12,0);
drawcube(67,9,-170,8,9,28,0);
drawcube(67,15,-220,8,15,18,0);
drawcube(67,15,-265,8,15,28,0);
drawcube(67,15,-330,8,15,28,0);
drawcube(-33,18,-364,25,18,10,0);
drawcube(25,28,-364,30,28,10,0);
drawcube(25,28,90,30,28,10,0);
drawcube(-33,18,90,25,18,10,0);
drawcube(0,60,-125,18,60,22,0);
drawcube(0,25,-225,8,25,28,0);
drawcube(0,25,0,8,25,28,0);
drawcube(-58,1,-135,4,0.5,215,0);
drawcube(58,1,-135,4,0.5,215,0);
drawcube(0,1,-345,60,0.5,4,0);
drawcube(0,1,75,60,0.5,4,0);
glEnd();
glutSwapBuffers();
}
void keyboard(unsigned char key, int x, int y)
{
switch (key)
{
case 'a':
glTranslatef(5.0, 0.0, 0.0);
break;
case 'd':
glTranslatef(-5.0, 0.0, 0.0);
break;
case 'w':
glTranslatef(0.0, 0.0, 5.0);
break;
case 's':
glTranslatef(0.0, 0.0, -5.0);
break;
}
display();
}
void resize(int width, int height)
{
if (height == 0) height = 1;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, width / height, 1.0, 400.0);
glTranslatef(0.0, -5.0, -150.0);
glMatrixMode(GL_MODELVIEW);
}
void drawcube(float xc, float yc, float zc, float x_offset, float y_offset, float z_offset, int color)
{
switch(color)
{
case 1:
glColor3f(1.0,0.0,0.0);
break;
case 2:
glColor3f(0.0,1.0,0.0);
break;
case 3:
glColor3f(0.0,0.0,1.0);
break;
}
glBegin(GL_QUADS);
glVertex3f(xc - x_offset,yc - y_offset,zc - z_offset);
glVertex3f(xc + x_offset,yc - y_offset,zc - z_offset);
glVertex3f(xc + x_offset,yc + y_offset,zc - z_offset);
glVertex3f(xc - x_offset,yc + y_offset,zc - z_offset);
glVertex3f(xc + x_offset,yc + y_offset,zc - z_offset);
glVertex3f(xc + x_offset,yc + y_offset,zc + z_offset);
glVertex3f(xc + x_offset,yc - y_offset,zc + z_offset);
glVertex3f(xc + x_offset,yc - y_offset,zc - z_offset);
glVertex3f(xc - x_offset,yc - y_offset,zc + z_offset);
glVertex3f(xc - x_offset,yc - y_offset,zc - z_offset);
glVertex3f(xc - x_offset,yc + y_offset,zc - z_offset);
glVertex3f(xc - x_offset,yc + y_offset,zc + z_offset);
glVertex3f(xc + x_offset,yc + y_offset,zc - z_offset);
glVertex3f(xc - x_offset,yc + y_offset,zc - z_offset);
glVertex3f(xc - x_offset,yc + y_offset,zc + z_offset);
glVertex3f(xc + x_offset,yc + y_offset,zc + z_offset);
glVertex3f(xc - x_offset,yc - y_offset,zc + z_offset);
glVertex3f(xc + x_offset,yc - y_offset,zc + z_offset);
glVertex3f(xc + x_offset,yc - y_offset,zc - z_offset);
glVertex3f(xc - x_offset,yc - y_offset,zc - z_offset);
glVertex3f(xc + x_offset,yc + y_offset,zc + z_offset);
glVertex3f(xc - x_offset,yc + y_offset,zc + z_offset);
glVertex3f(xc - x_offset,yc - y_offset,zc + z_offset);
glVertex3f(xc + x_offset,yc - y_offset,zc + z_offset);
glEnd();
}
回答1:
If you use Visual Studio, right-clic on your project, settings, debug, and set your working directory to the directory where your image stands.
If you use some other IDE, find a similar setting.
If you run your app from the console, cd to the directory of your image, and run your app from there. Use ../ if needed to navigate to your app.
回答2:
File paths in your code will be relative to your executable. If you're running your program via an IDE, the IDE may specify a different "working directory", and file paths will be relative to that.
To correct your issue, change the path in your code, or move the file in your file system. Alternately, you can use the IDE to set the working directory to the same location as your image as Calvin1602 suggests.
A typical set up would be to have a data directory in the same location as your executable, and store the files you're loading there.
来源：https://stackoverflow.com/questions/5384206/opengl-texture-issue