Added comments

diff --git a/Cura/gui/util/openglHelpers.py b/Cura/gui/util/openglHelpers.py
index 39b435c25e1744ea46ba830bbe3d58ff2e63e95a..6829bd387db70412f3a02177ccd928ec99f9ce2a 100644 (file)
--- a/Cura/gui/util/openglHelpers.py
+++ b/Cura/gui/util/openglHelpers.py
@@ -14,9 +14,7 @@ from OpenGL.GLUT import *
 from OpenGL.GLU import *
 from OpenGL.GL import *
 from OpenGL.GL import shaders
-glutInit()
-
-platformMesh = None
+glutInit() #Hack; required before glut can be called. Not required for all OS.
 
 class GLReferenceCounter(object):
        def __init__(self):
@@ -44,6 +42,7 @@ class GLShader(GLReferenceCounter):
                        fragmentShader = shaders.compileShader(fragmentProgram, GL_FRAGMENT_SHADER)
 
                        #shader.compileProgram tries to return the shader program as a overloaded int. But the return value of a shader does not always fit in a int (needs to be a long). So we do raw OpenGL calls.
+                       # This is to ensure that this works on intel GPU's
                        # self._program = shaders.compileProgram(self._vertexProgram, self._fragmentProgram)
                        self._program = glCreateProgram()
                        glAttachShader(self._program, vertexShader)
@@ -95,8 +94,10 @@ class GLShader(GLReferenceCounter):
                if self._program is not None and bool(glDeleteProgram):
                        print "Shader was not properly released!"
 
-#A Class that acts as an OpenGL shader, but in reality is not none.
 class GLFakeShader(GLReferenceCounter):
+       """
+       A Class that acts as an OpenGL shader, but in reality is not one. Used if shaders are not supported.
+       """
        def __init__(self):
                super(GLFakeShader, self).__init__()
 
@@ -127,10 +128,13 @@ class GLFakeShader(GLReferenceCounter):
                return ''
 
 class GLVBO(GLReferenceCounter):
+       """
+       Vertex buffer object. Used for faster rendering.
+       """
        def __init__(self, renderType, vertexArray, normalArray = None, indicesArray = None):
                super(GLVBO, self).__init__()
                self._renderType = renderType
-               if not bool(glGenBuffers):
+               if not bool(glGenBuffers): # Fallback if buffers are not supported.
                        self._vertexArray = vertexArray
                        self._normalArray = normalArray
                        self._indicesArray = indicesArray
@@ -144,7 +148,7 @@ class GLVBO(GLReferenceCounter):
                        self._hasNormals = normalArray is not None
                        self._hasIndices = indicesArray is not None
                        glBindBuffer(GL_ARRAY_BUFFER, self._buffer)
-                       if self._hasNormals:
+                       if self._hasNormals: #TODO: Add size check to see if arrays have same size.
                                glBufferData(GL_ARRAY_BUFFER, numpy.concatenate((vertexArray, normalArray), 1), GL_STATIC_DRAW)
                        else:
                                glBufferData(GL_ARRAY_BUFFER, vertexArray, GL_STATIC_DRAW)
@@ -176,8 +180,8 @@ class GLVBO(GLReferenceCounter):
                if self._hasIndices:
                        glDrawElements(self._renderType, self._size, GL_UNSIGNED_INT, c_void_p(0))
                else:
-                       batchSize = 996    #Warning, batchSize needs to be dividable by 4, 3 and 2
-                       extraStartPos = int(self._size / batchSize) * batchSize
+                       batchSize = 996    #Warning, batchSize needs to be dividable by 4 (quads), 3 (triangles) and 2 (lines). Current value is magic.
+                       extraStartPos = int(self._size / batchSize) * batchSize #leftovers.
                        extraCount = self._size - extraStartPos
                        for i in xrange(0, int(self._size / batchSize)):
                                glDrawArrays(self._renderType, i * batchSize, batchSize)
@@ -207,12 +211,18 @@ class GLVBO(GLReferenceCounter):
                        print "VBO was not properly released!"
 
 def glDrawStringCenter(s):
+       """
+       Draw string on current draw pointer position
+       """
        glRasterPos2f(0, 0)
        glBitmap(0,0,0,0, -glGetStringSize(s)[0]/2, 0, None)
        for c in s:
                glutBitmapCharacter(OpenGL.GLUT.GLUT_BITMAP_HELVETICA_18, ord(c))
 
 def glGetStringSize(s):
+       """
+       Get size in pixels of string
+       """
        width = 0
        for c in s:
                width += glutBitmapWidth(OpenGL.GLUT.GLUT_BITMAP_HELVETICA_18, ord(c))