How to load a bmp on GLUT to use it as a texture?

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I've been searching all around for a simple solution to add sprites to my OpenGl GLUT simple moon lander game in c++ and it appears I must use bmp's since they're easiest to load and use them as textures on a rectangle.

How exactly can I load the bmp's as textures though?


Look my simple c implementation function to load texture.

GLuint LoadTexture( const char * filename )
{

  GLuint texture;

  int width, height;

  unsigned char * data;

  FILE * file;

  file = fopen( filename, "rb" );

  if ( file == NULL ) return 0;
  width = 1024;
  height = 512;
  data = (unsigned char *)malloc( width * height * 3 );
  //int size = fseek(file,);
  fread( data, width * height * 3, 1, file );
  fclose( file );

 for(int i = 0; i < width * height ; ++i)
{
   int index = i*3;
   unsigned char B,R;
   B = data[index];
   R = data[index+2];

   data[index] = R;
   data[index+2] = B;

}


glGenTextures( 1, &texture );
glBindTexture( GL_TEXTURE_2D, texture );
glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,GL_MODULATE );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST );


glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,GL_REPEAT );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,GL_REPEAT );
gluBuild2DMipmaps( GL_TEXTURE_2D, 3, width, height,GL_RGB, GL_UNSIGNED_BYTE, data );
free( data );

return texture;
}

Above function returns the texture data. Store the texture data in variable

 GLuint texture
 texture= LoadTexture( "your_image_name.bmp" );

Now you can bind the texure using glBindTexture

glBindTexture (GL_TEXTURE_2D, texture);

c++ - How to load a bmp on GLUT to use it as a texture?, Look my simple c implementation function to load texture. GLuint LoadTexture( const char * filename ) { GLuint texture; int width, height; unsigned char * data;  I’ve just tried what you said but unfortunately it didn’t work. I use a bmp 256*256, 24 bits : the file seams to be loaded but the texture is not represented on the drawing !


Checkout my the TextureLoader (TextureLoader.h + TextureLoader.cpp) from OpenGL_3_2_Utils:

https://github.com/mortennobel/OpenGL_3_2_Utils

The two files does not depend on any other files and should also work seamless on any version of OpenGL (and any platform). Example usage can be found in the file comment.

loading bmp with glut - OpenGL: Basic Coding, I have tried this to load a bmp picture but it doesn't work! I'm using glut… unsigned texture[1];. void LoadTexture() { AUX_RGBImageRec  How to load a bmp on GLUT to use it as a texture? (3) How to load a bmp on GLUT to use it as a texture? Another very simple solution would be to use STB library, which can be found at GitHub - nothings/stb. All what is needed is one source file, the header file "stb_image.h".


You can use library GLAUX and SOIL(Simple OpenGL Image Library) . There are also other image libriries for OpenGL.

Tutorial 5 : A Textured Cube, Ok, i am taking some various Glut and OpenGL tutorials. So, to recap, can someone explain to me how to load textures like the tutorial tried to Create The Texture // Typical Texture Generation Using Data From The Bitmap  glut has nothing to do with the loading just load and create a texture using OpenGL only. all bitmaps loading tutorials for opengl will work with glut. you dont use glut functions in the loading.


How to load a bmp on GLUT to use it as a texture?

Another very simple solution would be to use STB library, which can be found at GitHub - nothings/stb.

All what is needed is one source file, the header file "stb_image.h". It doesn't require to link any library file or to compile any additional source file.

Include the header file and enable image reading by the setting the preprocessor definition STB_IMAGE IMPLEMENTATION:

#define STB_IMAGE_IMPLEMENTATION
#include <stb_image.h>

The image file can be read by the function stbi_load:

const char *filename = .....; // path and filename
int         req_channels = 3; // 3 color channels of BMP-file   

int width = 0, height = 0, channels = 0;
stbi_uc *image = stbi_load( filename, &width, &height, &channels, 3 ); 

When the image is loaded to a texture object, then GL_UNPACK_ALIGNMENT has to be set to 1. By default GL_UNPACK_ALIGNMENT is 4, so each line of an image is assumed to be aligned to 4 bytes. The pixels of a BMP-file in common have a size of 3 bytes and are tightly packed, this would cause a misalignment. After loading the image, the memory can be freed by stbi_image_free:

GLuint texture_obj = 0;
if ( image != nullptr )
{
    glGenTextures(1, &texture_obj);
    glBindTexture(GL_TEXTURE_2D, texture_obj);

    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 4); // default

    stbi_image_free( image );
}

OpenGL, loading BMP Textures?, NOTE: The Textures folder must be in the same one as this program. #else # include <GL/glut.h> # include <GL/glext.h> #endif using namespace Load external textures. void loadExternalTextures() { // Local storage for bmp image data. ya i found that, but didnt know how to use it when i first got it, i should be able to figure it out now though. I also found a bmp/texture loader via Glut, however i havent gotten it to work yet outside of the original example package it was in.


loadTextures.cpp, I am new to OpenGL, and c++ in general and id prefer to use Glut for loading code, please give the most simplified code to just explain the bmp/texture loading aspect of it. just load and create a texture using OpenGL only. Texture units are references to texture objects that can be sampled in a shader. Textures are bound to texture units using the glBindTexture function you've used before. Because you didn't explicitly specify which texture unit to use, the texture was bound to GL_TEXTURE0. That's why the default value of 0 for the sampler in your shader worked fine.


Loading Bitmaps for Textures, using Glut, The texture images MUST be availalbe in a directory // named "textures" in the Heights of texture imgages. void loadTextures() { // loads the 6 textures using the if (!bitmap) { printf("Failed to load image %s\n", textureFileNames[i]); continue; }​  The program simply loads a texture and render it as a quad. This quad can be rotated using mouse drag. The texture width and height must be a power of 2. Note: most of the comments in the loadPngImage function is copied from the example.c file from the libPNG source code.


Reading 2D Textures from Bitmap Images (C++ , OpenGL), my OpenGl GLUT simple moon lander game in c++ and it appears I must use bmp's since they're easiest to load and use them as textures on  But memory transfers are expensive; and texture decompression is free (there is dedicated hardware for that). Typically, using texture compression yields a 20% increase in performance. So you save on performance and memory, at the expense of reduced quality. Using the compressed texture. Let’s see how to load the image.