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OpenGL Programming/Basics/LinesPoints

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Note that this is for very outdated versions of OpenGL.

Drawing points

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glBegin(GL_POINTS);
  glVertex2f(0.5f, 0.5f); 
  glVertex2f(0.5f, -0.5f); 
  glVertex2f(-0.5f, 0.5f); 
  glVertex2f(-0.5f, -0.5f); 
glEnd();

Drawing lines

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/* Draws two horizontal lines */
glBegin(GL_LINES);
  glVertex2f(0.5f, 0.5f); 
  glVertex2f(-0.5f, 0.5f); 
  glVertex2f(-0.5f, -0.5f); 
  glVertex2f(0.5f, -0.5f); 
glEnd();

Loop of lines

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/* Draws a square */
glBegin(GL_LINE_LOOP);
  glVertex2f(0.5f, 0.5f); 
  glVertex2f(-0.5f, 0.5f); 
  glVertex2f(-0.5f, -0.5f); 
  glVertex2f(0.5f, -0.5f); 
glEnd();

Connected lines

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/* Draws a 'C' */
glBegin(GL_LINE_STRIP);
  glVertex2f(0.5f, 0.5f); 
  glVertex2f(-0.5f, 0.5f); 
  glVertex2f(-0.5f, -0.5f); 
  glVertex2f(0.5f, -0.5f); 
glEnd();