c++ - Problems loading bitmap data into an OpenGL texture -

unfortunatly, have problems glbindtexture().

when try bind bitmap image skybox see white. tested other figures , not work. sure problem in engine class.

this engine.cpp, here load bitmap et cetra:

#include <windows.h> #include <gl/gl.h>  #include <iostream> #include "engine.h"  unsigned char* engine::getimagecontents(char path[], bitmapinfoheader* bih) {     file* input; fopen_s(&input, path, "rb");      if (input != null) {         bitmapfileheader bfh;         fread(&bfh, sizeof(bfh), 1, input);         fread(&bih, sizeof(bih), 1, input);          unsigned char* data =             new unsigned char[bih->biwidth * bih->biheight * bih->bibitcount / 8];          fread(data, sizeof(data), 1, input);         fclose(input);          return data;     } else {         return null;     } }  void engine::bindtexture(char path[]) {     this->bindtexture(this->gettextureid(path)); }  void engine::bindtexture(unsigned int id) {     if (id != this->boundtexture) {         glbindtexture(gl_texture_2d, id);         this->boundtexture = id;     } }  unsigned int engine::gettextureid(char path[]) {     if (this->texturemap.find(path) != this->texturemap.end()) {         return this->texturemap[path];     } else {         unsigned int id; glgentextures(1, &id);         bitmapinfoheader bih;         unsigned char* data = this->getimagecontents(path, &bih);         this->setuptexture(data, id, bih.biwidth, bih.biheight);         this->texturemap.insert(std::pair<char*, unsigned int>(path, id));         return id;     } }  void engine::setuptexture(unsigned char* data, unsigned int id, long width, long height) {     this->setuptexture(data, id, width, height, false); }  void engine::setuptexture(unsigned char* data, unsigned int id, long width, long height, bool clamp) {     std::cout << height << std::endl;     this->bindtexture(id);     gltexparameteri(gl_texture_2d, gl_texture_min_filter, gl_nearest);     gltexparameteri(gl_texture_2d, gl_texture_mag_filter, gl_nearest);     gltexparameteri(gl_texture_2d, gl_texture_wrap_s, clamp ? gl_clamp : gl_repeat);     gltexparameteri(gl_texture_2d, gl_texture_wrap_t, clamp ? gl_clamp : gl_repeat);     glteximage2d(gl_texture_2d, 0, gl_rgba, width, height, 0, gl_rgba, gl_unsigned_int, data); } 

i use class this:

engine::bindtexture(path); 

any ideas?

i see few possible problems.

1. are sure load not compressed .bmp file, please check bfh.bicompression
2. you can use gl_rgba if bih->bibitcount == 32, try use gl_rgb
3. try use gl_unsigned_byte instead of gl_unsigned_int
4. please check image size, think skybox should 128x128, 256x256, 512x512, i.e. power-of-2 texture size
5. replace
   fread(data, sizeof(data), 1, input);
   on
   fread(data, 1, bih->biwidth * bih->biheight * bih->bibitcount / 8, input);