Messages

1

Graphics / GetPixelsPtr() and glTexImage2D

« on: April 21, 2011, 07:17:06 pm »

Hehe, funny you should mention that, I just checked, and the values are the  same across the program and across the FreeImage values too.

2

Graphics / GetPixelsPtr() and glTexImage2D

« on: April 21, 2011, 06:44:19 pm »

Hello,
I'm trying to switch from using freeglut and Freeimage to SFML. The first step involved loading images from a self created .dat file as a sf::Image object, and passing it into a texture in OpenGL 3.2. The image does get loaded properly, seeing as I can save it and it shows correctly. However, when I call glTexImage2D with GetPixelsPtr() as the data array, my program crashes when it tries to draw the array in OpenGL with glDrawArrays. Mind you, the sf::Image stuff is the only piece of code I have implemented so far. When I was using FreeImage, I could get an array of BYTES (unsigned chars) and pass it to the texture. As far as I understand it, GetPixelsPtr returns a similar array.

I've printed the values in the FreeImage and sf::Image byte arrays both to files to see if there were any odd values, and apart from different values (FreeImage stores its image data somewhat differently I think), I can't see anything out of the ordinary. The code that involves binding to the texture is this:

Code: [Select]


#include    <iostream>
#include    <cstdlib>
#include    <GL/glew.h>
#include    "Texture.h"

//-----------------------------------------------------------------------------
//       Class:  Texture
//      Method:  Texture
// Description:  constructor
//-----------------------------------------------------------------------------
Texture::Texture ()
{
}  // -----  end of method Texture::Texture  (constructor)  -----

//-----------------------------------------------------------------------------
//       Class:  Texture
//      Method:  Texture
// Description:  constructor
//-----------------------------------------------------------------------------
Texture::Texture ( GLenum textureTarget, const sf::Image& png ) :
    textureTarget_(textureTarget), png_(png)
{
    width_ = png_.GetWidth();
    height_ = png_.GetHeight();
}  // -----  end of method Texture::Texture  (constructor)  -----

//-----------------------------------------------------------------------------
//       Class:  Texture
//      Method:  Texture
// Description:  destructor
//-----------------------------------------------------------------------------
Texture::~Texture ()
{
} // -----  end of method Texture::Texture  -----

//-----------------------------------------------------------------------------
//       Class:  Texture
//      Method:  load
// Description:  Loads a targa image from the file.
//-----------------------------------------------------------------------------
    void
Texture::load ()
{
    glGenTextures(1, &texID);
    glBindTexture(textureTarget_, texID);
    glTexParameteri(textureTarget_, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(textureTarget_, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexImage2D(textureTarget_, 0, GL_RGBA, width_, height_, 0, GL_RGBA,
                 GL_UNSIGNED_BYTE, png_.GetPixelsPtr()); // This is where it fails
   
    // Unbind everything
    glBindTexture(textureTarget_, 0);
} // -----  end of method Texture::load  -----

//-----------------------------------------------------------------------------
//       Class:  Texture
//      Method:  bind
// Description:  Binds the texture data into the shaders
//-----------------------------------------------------------------------------
    void
Texture::bind ( const GLuint& shader )
{
    glBindTexture(textureTarget_, texID);
    GLuint gSampler = glGetUniformLocation(shader, "gSampler");
    glUniform1i(gSampler, 0);
} // -----  end of method Texture::bind  -----