Demo/GLExcess/Texture.cpp

   1 /*
   2 GLExcess v1.0 Demo
   3 Copyright (C) 2001-2003 Paolo Martella
   4
   5 This program is free software; you can redistribute it and/or
   6 modify it under the terms of the GNU General Public License
   7 as published by the Free Software Foundation; either version 2
   8 of the License, or (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14 */
  15
  16 #include "Texture.h"
  17
  18 Texture::Texture() {tID=0;}
  19 Texture::~Texture(){Kill();}
  20 bool Texture::Create(char* FileName)
  21 {
  22         Kill();
  23         glGenTextures(1, &tID);
  24         tID++; // Use an offset of +1 to differentiate from non-initialized state.
  25         glBindTexture(GL_TEXTURE_2D, tID-1);
  26         glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S, GL_REPEAT);
  27         glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T, GL_REPEAT);
  28         glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  29         glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
  30         return true;
  31 }
  32
  33 void Texture::Kill()
  34 {
  35         if(tID)
  36         {
  37                 tID--;
  38                 glDeleteTextures(1, &tID);
  39                 tID=0;
  40         }
  41 }
  42 GLuint pow2(GLuint exp)
  43 {
  44         GLuint result=1;
  45         if (!exp) return result;
  46         for (GLuint a=0; a<exp; a++)
  47         {
  48                 result*=2;
  49         }
  50         return result;
  51 }
  52 void Texture::Use()
  53 {
  54         glBindTexture(GL_TEXTURE_2D,tID-1);
  55 }
  56 bool Texture::Load(char* Opaque)
  57 {
  58         if(Opaque==0) return false;
  59         if (!Create(Opaque)) return false;
  60         char * rgbdata;
  61         GLuint w,h;
  62         FILE * fhandle=NULL;
  63         fhandle=fopen(Opaque,"rb");
  64         if (!fhandle) return false;
  65         char ww,hh;
  66         fread(&ww,sizeof(char),1,fhandle);
  67         w=pow2(ww-48);
  68         fread(&hh,sizeof(char),1,fhandle);
  69         h=pow2(hh-48);
  70         GLuint size=w*h*3;
  71         rgbdata=new char[size];
  72         GLuint read=fread(rgbdata,sizeof(char),size,fhandle);
  73         if (read!=size) return false;
  74         fclose(fhandle);
  75         gluBuild2DMipmaps(GL_TEXTURE_2D,3,w,h,GL_RGB,GL_UNSIGNED_BYTE,rgbdata);
  76         delete [] rgbdata;
  77         return true;
  78 }