加载png作为纹理并将其绑定到球体

Question

我找不到任何有关如何加载PNG文件并将其用作纹理将其绑定到球体的不错的教程。是否有任何库函数可以执行此操作？我将如何将其绑定到球体上？我已经尝试过了，它没有用，没有错误，但是纹理没有加载到球体上。我用glutMainLoop（）之前的特定文件调用LoadTexture。

这是我的文件加载代码：

GLuint LoadTexture( const char * filename, int width, int height )
    {
GLuint texture;
unsigned char * data;
FILE * file;

//The following code will read in our PNG 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 ); //generate the texture with 

glBindTexture( GL_TEXTURE_2D, texture ); //bind the texture

glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, 
GL_MODULATE ); //set texture environment parameters



//even better quality, but this will do for now.
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 
//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

}

这是我创建球体的地方

void renderScene(void) {

// Clear Color and Depth Buffers
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

 glEnable( GL_TEXTURE_2D );
// Reset transformations
glLoadIdentity();
glBindTexture( GL_TEXTURE_2D, texture );
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

glPushMatrix();
glTranslatef(0.0,2.0,-6);
glRotatef(angle, 0.0f, 2.0, -6.0f);
glutSolidSphere(1,50,50);
glPopMatrix();


angle+=0.4f;
glDisable(GL_TEXTURE_2D);
glutSwapBuffers();
 }

我做对了吗？

Answer 1

您正在将压缩的PNG数据输入到OpenGL。必须先将其解压缩，因为OpenGL纹理函数无法理解PNG。您可以使用某些图像库将其解压缩，例如stb_image.c