Use the framebuffer pitch to calculate the correct offset.
Fixes garbled rendering on framebuffer that have
pitch != x_resolution * bpp / 8.
The demo application is unaffected as the pitch always aligns with
the x resolution of the window.
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
The software rasterizer is to be used with raw framebuffer
devices, where no GPU or X11 is available.
The demo emulates a raw framebuffer on X11 using XShmImage / XImage.
Features implemented:
* Drawing primitives
* Drawing polygons (using Darel Rex Finley algorithm)
* Drawing arcs and circles (using Bresenham's elipses algorithm)
* Drawing images using nearest filtering
* Bounds check on every operation
* Fastpath for lines
* Font rendering using nearest filtering
* Window resize
* Thread safe implementation by using a context
* Fixed lower and upper scissors on fast-path
* Adapted coding style to nuklear's style
* Implemented text scissors
Color formats:
Define one of them at compile time.
* RAWFB_RGBX_8888 (32bpp)
* RAWFB_XRGB_8888 (32bpp)
Tested:
The library has been tested on Lenovo Thinkpad T500 and is able to render
more than 30fps on a single core with no further optimizations and VSNYC enabled.
TODO:
* Improve font rendering by using filters.
* Account font foreground color.
Usage:
The raw framebuffer library needs a "texture" that holds the prerendered
font data. The texture is used at runtime to blit the letters onto screen.
You have to provide the framebuffer address, dimension and pitch.
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
