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Video Interface Controller library

VIC is an universal, lightweight, extremly fast and powerful C++ library for driving graphic, dot, alpha numeric and seven-segment displays.

The VIC lib is beta and still under heavy development. If you have specific questions, do not hesitate to contact me!
v0.3.0 with major design improvements is coming up!

Highlights

  • Universal library for graphic and alpha numeric displays
  • HEADER ONLY implementation, no module compilation
  • Platform and CPU independent code, NO dependencies, NO STL, NO new/delete, NO float - just clean and pure C++11
  • Platform independent driver design, the very same low level display driver runs everywhere
  • High performance primitive rendering of lines, circles, triangles, boxes, text etc.
  • Support of advanced controls like gauges, bars, (radio) buttons, checkboxes etc.
  • Support of unlimited number of sprites for moving objects
  • Multiple heads support, as many displays as you may like in one system
  • Multihead driver, combine any number of (even different) single displays to one big display
  • Support of various color formats from 1 to 32 bpp displays
  • Support for different font formats (proportional, monospace), ASCII/UTF-8 support
  • Brush shape support for line drawing
  • Antialiasing support for smooth primitive and text/font rendering
  • Framebuffer and viewport support
  • Clipping region support
  • Gradient color rendering support
  • Alpha blending support
  • NO floating point math, only fast integer operations
  • VERY clean and stable C++ code, LINT and L4 warning free, automotive ready
  • Very easy to use and fast implemention of own/new display drivers
  • Doxygen commented code
  • MIT license

What is VIC NOT?

VIC is not meant to be a full bloated window manager, widgets, dialogs, theme rendering framework. If you need an advanced windowed GUI, there are many other cool libraries around, like µC/GUI, StWin etc.

To be done (and implemented)

  • Improve anti aliasing support
  • Sprite support
  • Add more standard and high quality fonts

Design of VIC

Basicly every display needs a driver. But unlike as in many other designs, the driver is the highest class of which the head (display) is instanciated. A graphic driver only needs to implement drv_pixel_set_color and drv_pixel_get functions. But most modern display controllers can provide more sophisticated functions for native line/box rendering, block moving etc. If a controller can provide such special functions, the according function is implemented in the driver by simply overriding the virtual function of the gpr base class. All graphic functions which the controller/driver can't provide natively are handled by the gpr. Of cource, native rendering on a specialized LCD controller is always faster and should be prefered.

Class design

base

The base class provides common functions.

gpr

The Graphic Primitive Renderer provides fast rendering functions for graphic primitives. The gpr doesn't use any floating point math, only fast integer operations. Furthermore the gpr should be a collection of reference implementations of the most modern, fast and reliable primitive rendering algorithms. So, if you find any errors, have speed improvements or even a better algorithm for some primitives - please share and contribure!

txr

The Text Renderer is responsible for rendering text fonts on graphic displays. It supports monospaced and proportional fonts.

drv

The base class of the head driver which adds some mandatory driver routines. All color calculations are done in ARGB 32 bit format. If a display has less colors, like 15 bit RGB, the specific driver class is responsible for color reduction. Conversion routines provides the drv class.

head

The specific display driver. A display together with its controller is referenced here as head. And head is the namespace of all specific drivers. All virtual functions of the gpr and drv are overridden here.

ctrl

The base class for advanced controls like gauges, progress bars, checkboxes, buttons etc.

Usage

Using VIC is really easy and fun. In a single head design (just one display in the system) you create your head first by instancing the according driver. E.g. on a Windows (emulation/test) platform this would be:

// Create a screen of 240 * 120 pixel with a viewport of the same size (240 * 120)
// The viewport has an offset of 0,0 and the window is placed at 100,100 on the windows desktop
// For development convinience a horizontal and vertical zoom factor of 4 is selected
víc::head::windows<240,120,240,120> _head(0, 0, 100, 100, 4, 4);
_head.init();  // explicit head init

Now you can perform any operations on the head:

_head.pen_set_color(vic::color::brightblue);  // select bright blue drawing color
_head.line(10, 10, 40, 40);                   // draw a line from 10,10 to 40,40

// write some text
_head.pen_set_color(vic::color::yellow);
_head.text_set_font(vic::font::arial_num_16x24_aa4);
_head.text_string_pos(10, 50, (const std::uint8_t*)"12,34.56-7890");

If you need multiple displays in your design, we are talking about a "multiple heads" scenario. All heads are independent. Let's create two independent heads:

vic::head::windows<240,120,240,120> _head0(0, 0, 0,  00, 2, 2);
vic::head::windows<240,120,240,120> _head1(0, 0, 0, 200, 2, 2);
_head0.init();  // explicit head 0 init
_head1.init();  // explicit head 1 init

Using head 0:

_head0.pen_set_color(vic::color::brightblue);
_head0.line(10, 10, 40, 40);

And using head 1 (eg. for system debug, status. etc):

head1.pen_set_color(vic::color::red);
head1.box(100, 100, 120, 120);

Or you can combine multiple single displays to one big screen. It's a common way to create big screens out of single modules. This is done by using the multihead driver.

// Create 3 MAX7219 heads with a rotation of 90° on SPI device ID 1,2 and 3
// The single heads have a resolution of 8 * 8 pixels
vic::head::MAX7219<8U, 8U> _head0(drv::orientation_90, 1U);
vic::head::MAX7219<8U, 8U> _head1(drv::orientation_90, 2U);
vic::head::MAX7219<8U, 8U> _head2(drv::orientation_90, 3U);
// Create the multihead out of the three heads with offsets of 0, 8 and 16 pixels
// So the multihead has a srceen resolution of 24 * 8 pixels
vic::head::multihead<24U, 8U, 3U> _multihead = { {_head0, 0U, 0U}, {_head1, 8U, 0U}, {_head2, 16U, 0U} };

// Now, use the multihead like a normal head
_multihead.line(0, 0, 23, 7);

License

vic is written under the MIT licence.