NOTES.txt

Meshes
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  - Meshes can have multiple segments each with their own material (SegmentMaterial) and primitive type (GL_TRIANGLES, GL_QUADS, etc.)
  - Each segment material can have their own lighting parameters and textures.
  - All mesh segments must define the same data in all segments. If normals are supplied in one segment then all segments are required to have them defined.
  - A mesh has indexes that are shared by all segments.
  - The mesh has a renderable configuration which defines how the data will be sent to OpenGL. For example colors can have a size 3 (RGB) or 4 (RGBA) and can be GL_BYTE, GL_FLOAT or GL_UNSIGNED_BYTE.
  - An AABB is attached to a mesh which represents a bounding box in object coordinates.
  - A mesh can have a material (MeshMaterial) which overrides which shader it is rendered with.

OpenGL 1.X
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  - You must choose withOpenGL33ProfileCompatibility() in your Configuration.
  - This is the default mode for Graphics.
  - Shaders cannot be used.
  - You can render objects using Display Lists, Immediate Mode, Vertex Arrays and VBOs.
  - You must not attach any shaders to a mesh material.
  - The bind state uses gl*ClientState and gl*Pointer calls.
  - You should not used named texture types (defined in net.smert.frameworkgl.opengl.TextureType) instead use TextureType.TEXTURE[0-8].

OpenGL 2.1
========================================
  - You must choose withOpenGL33ProfileCompatibility() in your Configuration.
  - You need to enable the correct renderer and renderable factory with Fw.graphics.switchRenderableFactoryAndRenderer(2).
  - You must render all objects with a shader.
  - You can render objects using Display Lists, Immediate Mode, Vertex Arrays and VBOs (Immediate Mode & Display Lists do not appear to work for Intel drivers).
  - You must use the matrix helper instead of OpenGL matrix functions.
  - The bind state uses gl*VertexAttribArray and glVertexAttribPointer.

OpenGL 3.2
========================================
  - You must choose withOpenGL32ProfileCore() in your Configuration.
  - You need to enable the correct renderer and renderable factory with Fw.graphics.switchRenderableFactoryAndRenderer(3).
  - There are no built-in shaders for this version.
  - You must render all objects with a shader.
  - You can render objects using Vertex Arrays and VAOs.
  - You must use the matrix helper instead of OpenGL matrix functions.
  - The bind state uses gl*VertexAttribArray (glVertexAttribPointer is used when the VBO is created and is saved by the VAO).

OpenGL 3.3
========================================
  - You must choose withOpenGL33ProfileCore() in your Configuration.
  - You need to enable the correct renderer and renderable factory with Fw.graphics.switchRenderableFactoryAndRenderer(3).
  - You must render all objects with a shader.
  - You can render objects using Vertex Arrays and VAOs.
  - You must use the matrix helper instead of OpenGL matrix functions.
  - The bind state uses gl*VertexAttribArray (glVertexAttribPointer is used when the VBO is created and is saved by the VAO).

Renderables
========================================
  - These are created from a mesh and represents how OpenGL will be rendering the object (Display list, VBO, etc.).
  - Vertex arrays, vertex buffer objects and vertex array objects have a bind state which is called once before the render call. This bind state sets up gl*ClientState, gl*Pointer, gl*VertexAttribArray and glVertexAttribPointer depending on the OpenGL version.

Shaders
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  - GLSL 120 & 330 shaders do not rely on built-in attributes, uniforms and variables (GLSL 120 still uses gl_FragColor and gl_FragData).
  - All shaders reference a global DefaultAttribLocations by default (during compiling) for locating vertex attributes and must be consistent across all shaders. The bind state uses this information to enable/disable the correct vertex attributes.
  - If you make changes to the global DefaultAttribLocations then you must update the bind state (Renderable.bindState[2 or 3].setAttribLocations(GL.defaultAttribLocations)).
  - Vertex lit shaders emulate glEnable(GL_COLOR_MATERIAL) and glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE) by default.
  - The current shader is changed by calling Fw.graphics.switchShader() and all Fw.render* methods will use it unless a mesh material has a shader assigned to it.

Textures
========================================
  - Textures attached to a mesh's segment material have a texture type (defined in net.smert.frameworkgl.opengl.TextureType) and each type has to be mapped to a texture unit (GL_TEXTURE0, etc.). This mapping is defined on a per shader basis.