* remove duplicate code between draw functions and STROKE_FONT used in GAL. Use only STROKE_FONT methods in draw, plot and test DRC function for texts. It remove slightly different shapes between GAL and other calculations.
* fix incorrect bounding box for texts with overbar. Especially noticeable for texts with overbar inside a copper zone in Pcbnew.
* fix a few minor other bugs related to graphic texts.
I tried to merge some constants used both in legacy mode and gal mode (which were, before this patch, separate constants).
There is still a serious work to avoid different calculation code for the same text in draw and plot functions.
Work in progress to merge these calculation functions.
Moved scaling of font glyphs to the moment when they are created (eliminated a few multiplications unnecessary variables).
Changed some magic numbers into constants.
New classes:
- VIEW - represents view that is seen by user, takes care of layer ordering & visibility and how it is displayed (which location, how much zoomed, etc.)
- VIEW_ITEM - Base class for every item that can be displayed on VIEW (the biggest change is that now it may be necessary to override ViewBBox & ViewGetLayers method for derived classes).
- EDA_DRAW_PANEL_GAL - Inherits after EDA_DRAW_PANEL, displays VIEW output, right now it is not editable (in opposite to usual EDA_DRAW_PANEL).
- GAL/OPENGL_GAL/CAIRO_GAL - Base Graphics Abstraction Layer class + two different flavours (Cairo is not fully supported yet), that offers methods to draw primitives using different libraries.
- WX_VIEW_CONTROLS - Controller for VIEW, handles user events, allows zooming, panning, etc.
- PAINTER/PCB_PAINTER - Classes that uses GAL interface to draw items (as you may have already guessed - PCB_PAINTER is a class for drawing PCB specific object, PAINTER is an abstract class). Its methods are invoked by VIEW, when an item has to be drawn. To display a new type of item - you need to implement draw(ITEM_TYPE*) method that draws it using GAL methods.
- STROKE_FONT - Implements stroke font drawing using GAL methods.
Most important changes to Kicad original code:
* EDA_ITEM now inherits from VIEW_ITEM, which is a base class for all drawable objects.
* EDA_DRAW_FRAME contains both usual EDA_DRAW_PANEL and new EDA_DRAW_PANEL_GAL, that can be switched anytime.
* There are some new layers for displaying multilayer pads, vias & pads holes (these are not shown yet on the right sidebar in pcbnew)
* Display order of layers is different than in previous versions (if you are curious - you may check m_galLayerOrder@pcbnew/basepcbframe.cpp). Preserving usual order would result in not very natural display, such as showing silkscreen texts on the bottom.
* Introduced new hotkey (Alt+F12) and new menu option (View->Switch canvas) for switching canvas during runtime.
* Some of classes (mostly derived from BOARD_ITEM) now includes ViewBBox & ViewGetLayers methods.
* Removed tools/class_painter.h, as now it is extended and included in source code.
Build changes:
* GAL-based rendering option is turned on by a new compilation CMake option KICAD_GAL.
* When compiling with CMake option KICAD_GAL=ON, GLEW and Cairo libraries are required.
* GAL-related code is compiled into a static library (common/libgal).
* Build with KICAD_GAL=OFF should not need any new libraries and should come out as a standard version of Kicad
Currently most of items in pcbnew can be displayed using OpenGL (to be done are DIMENSIONS and MARKERS).
More details about GAL can be found in: http://www.ohwr.org/attachments/1884/view-spec.pdf
Maciej Suminski
jean-pierre charras
Dick Hollenbeck
Camille Delbegue