opengl纹理 [英] opengl texturing
本文介绍了opengl纹理的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
#include windows.h
#include gl\gl.h
#include gl\glut.h
#include stdlib.h
#include iostream>
#define ROAD 0
struct Image
{
unsigned long size_x;
unsigned long size_y;
char * data;
};
typedef struct Image Image;
const int textureCount = 1;
图片myTextureData [textureCount];
GLuint theTexture [textureCount];
char * textureFilenames [textureCount] = {road.bmp};
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）;
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）;
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;
}
void display（void）
{
if（is_depth）
glClear（GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT）;
else
glClear（GL_COLOR_BUFFER_BIT）;
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）;
drawingcube（-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（）;
}
int imageLoader（const char * filename，Image * image）
{
FILE * file;
unsigned long size;
unsigned long i;
无符号短整型平面;
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\\\
，finalName ）;
return 0;
}
fseek（file，18，SEEK_CUR）;
glTexCoord2f（1.0，0.0）;
if（（i = fread（& image-> size_x，4，1，file））！= 1）
{
printf ％s.\\\
，finalName）;
return 0;
}
if（（i = fread（& image-> size_y，4，1，file））！= 1）
{
printf 从％s.\\\
读取高度错误，finalName）;
return 0;
}
size = image-> size_x * image-> size_y * 3;
if（（fread（& planes，2，1，file））！= 1）
{
printf（Error from planes from％s.\\\
，finalName）;
return 0;
}
if（planes！= 1）
{
printf（％s不是1：％u\\\
，finalName，planes ）;
return 0;
}
if（（i = fread（& bpp，2，1，file））！= 1）
{
printf from％s.\\\
，finalName）;
return 0;
}
if（bpp！= 24）
{
printf（Bpp from％s is not 24：％u\\\
，finalName，bpp ）;
return 0;
}
fseek（file，24，SEEK_CUR）;
image-> data =（char *）malloc（size）;
if（image-> data == NULL）
{
printf（为颜色校正的图像数据分配内存错误）;
return 0;
}
if（（i = fread（image-> data，size，1，file））！= 1）
{
printf从％s.\\\
读取图像数据，finalName）;
return 0;
}
for（i = 0; i {
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
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）;
}
}
解决方案
从不调用 textureLoader（）。
或 glBindTexture（）
除了 textureLoader（） glBegin（） s。
hi im trying to texture the floor of my level but when i call it the program compiles ok but the texture doesnt appear any help would be great
#include windows.h
#include gl\gl.h
#include gl\glut.h
#include stdlib.h
#include iostream>
#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"};
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);
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);
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;
}
void display(void)
{
if (is_depth)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
else
glClear(GL_COLOR_BUFFER_BIT);
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();
}
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);
}
}
解决方案
You never call textureLoader().
Or glBindTexture(), other than in textureLoader(), which you don't call.
Also, don't nest glBegin()s.
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