58 lines
2.4 KiB
Plaintext
58 lines
2.4 KiB
Plaintext
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/**
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* \dir src/graphics
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* \brief Graphics engine
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*/
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/**
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* \namespace Gfx
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* \brief Namespace for (new) graphics code
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*
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* This namespace was created to avoid clashing with old code, but now it still serves,
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* defining a border between pure graphics engine and other parts of application.
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*/
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/**
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* \page graphics Graphics engine
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*
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* The graphics engine consists of 3 parts:
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* * core - low-level device code (currently with only OpenGL implementation)
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* * main engine - managing and displaying 3D environment (terrain, models, water, sky, effects, camera, etc.)
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* * 2D interface - classes drawing the 2D interface (menus, buttons, editor, HUD elements)
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*
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* \section coords Drawing coordinates
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*
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* \subsection coords2d 2D interface
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*
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* 2D interface is drawn by setting orthogonal projection yielding the following 2D coordinate system:
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*
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* \image html 2d_coord.png
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*
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* Depth test is disabled for 2D interface, so Z coordinates are irrelevant.
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*
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* The coordinate system is constant and is independent of resolution or screen proportions.
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*
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* UI elements are laid out by computing these standard coordinates, using 640x480 resoultion as reference.
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* That is, their coordinates are computed like so: x = 32.0f/640.0f, y = 400.0f/480.0f.
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*
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* \subsection coords3d 3D environment
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*
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* 3D environment is drawn using the following coordinate system:
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*
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* \image html 3d_canonical_coords.png
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*
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* The base coordinate system is like depicted above with viewport on Z=0 plane.
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* The coordinates are then transformed by world, view and projection matrices to yield screen coordinates.
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*
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* The base coordinates are also model coordinates. All models must be modelled in this setup.
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* Scale should be kept proportional to existing models.
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*
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* The world matrix defines the transformation from model coordinate system to the point and orientation
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* in 3D scene. This matrix is defined one per every <i>graphics engine</i> object.
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* (Note the emphasis - the objects as defined in game engine do not necessarily correspond to
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* one graphics engine object.)
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*
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* The view and projection matrices define the viewing point and volume, and are mostly managed by Gfx::CCamera.
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* View is defined by Math::LoadViewMatrix() function, that is using 3 vectors: eye position (eyePt),
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* target point (lookatPt) and up vector (upVec). Projection is always perspective,
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* with changing view angle (focus).
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*/
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