Blending 예제
http://dis.dankook.ac.kr/lectures/cg08/entry/blending-예제

Blending Filter 예제
http://dis.dankook.ac.kr/lectures/cg08/entry/blending-filter-예제

// Default (no blending) = Cs*1
glBlendFunc(GL_ONE, GL_ZERO)      
// Draw background only = Cd*1
glBlendFunc(GL_ZERO, GL_ONE)  // Addition Blending = Cs*1 + Cd*1
glBlendFunc(GL_ONE, GL_ONE)    
// Alpha blending (back-to-front) = Cs*As + Cd*(1-As)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)  // Brighten the scene = Cs*As + Cd*1
glBlendFunc(GL_SRC_ALPHA, GL_ONE)  // Multiplicative blending = Cd*Cs
glBlendFunc(GL_ZERO, GL_SRC_COLOR)// darken the scene = Cd*As
glBlendFunc(GL_ZERO, GL_SRC_ALPHA);// Invert all the colors = Cs*(1-Cd)
glBlendFunc(GL_ONE_MINUS_DST_COLOR, GL_ZERO)

/// init texture
void initTexture(char *filename, GLuint& textureID, GLint param=GL_REPEAT)
{
// 중간 생략
  glGenTextures(1, &textureID);
  glBindTexture(GL_TEXTURE_2D, textureID);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, param);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, param);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  glTexImage2D(GL_TEXTURE_2D, 0, numComponents == 3 ? GL_RGB : GL_RGBA, imageWidth, imageHeight,
      0, numComponents == 3 ? GL_RGB : GL_RGBA, GL_UNSIGNED_BYTE, imageBuffer);
  glBindTexture(GL_TEXTURE_2D, 0);
}

/// Draw
void draw()
{
 glBindTexture(GL_TEXTURE_2D, texID1);
 glBegin(GL_QUADS);
  glNormal3f(0, 0, 1);
  glTexCoord2i( __________________ );
  glVertex3f(-2.0, -1.0, 0.0);
  glTexCoord2i(__________________);
  glVertex3f(-0.1, -1.0, 0.0);
  glTexCoord2i(__________________);
  glVertex3f(-0.1, 1.0, 0.0);
  glTexCoord2i(__________________);
  glVertex3f(-2.0, 1.0, 0.0);
 glEnd();
}

Texture binding, texture generate, texture filtering, texture subimage, texture mapping by procedural definition & using imagefile, mipmapping, texture environment setting (modulate/decal), texture distorting, texture transformation, flipbook animation, etc
http://dis.dankook.ac.kr/lectures/cg08/entry/texture-mapping-예제

Texture filtering & environment paramaters
http://dis.dankook.ac.kr/lectures/cg08/entry/texture-filtering-environment-parameters-예제

wrapping parameters (REPEAT | CLAMP)

magnification/minification filter parameters (NEAREST | LINEAR | LINEAR_MIPMAP_LINEAR)

environment parameters (MODULATE | DECAL | BLEND | REPLACE)

Texture generation
http://dis.dankook.ac.kr/lectures/cg08/entry/texture-generation-예제

Multitexturing
http://dis.dankook.ac.kr/lectures/cg09/entry/OPENGL-Multitexturing

multipass-multitexturingsingpass-multitexturing
Billboarding
http://dis.dankook.ac.kr/lectures/cg09/entry/OPENGL-Billboarding

Before Billboarding
After Billboarding