LaTeX Rendering on Teensy with MicroTeX
A small lazy project rendering MicroTeX to a TFT display with OpenFontRender
The font size, position and colour can all be easily changed. The big thing here though is that its rendered at runtime.
The following code produces the image below:
LaTeX::init("/res");
Serial.println("Parsing LaTeX...");
auto render = LaTeX::parse(
LR"(\frac{d}{dt}
\begin{bmatrix}
x \\ \dot{x} \\ l\phi \\ \dot{l\phi}
\end{bmatrix} = \begin{bmatrix}
0 & 1 & 0 & 0 \\
0 & 0 & \omega_0^2 - \omega_1^2 & 0 \\
0 & 0 & 0 & 1 \\
0 & 0 & \omega_0^2 & 0
\end{bmatrix} )", // LaTeX code
TFT_WIDTH,
20, // font size (in point)
10, // space between 2 lines (in pixel)
WHITE // foreground color
);
if (render) {
Serial.printf("Render size: %d x %d\n", render->getWidth(), render->getHeight());
OpenFontRender ofr;
ofr.setSerial(Serial);
ofr.setDrawer(tft);
Graphics2D_tft g2d(&tft, &ofr);
render->draw(g2d, 0, 100); // Draw at position (0, 0)
} else {
Serial.println("Failed to parse LaTeX");
}
Theres still some issues of course like the middle line of right brackets but overall its pretty neat.
This used the following libraries:
- MicroTeX
- tinyxml2
- OpenFontRender
- bodmer/TFT_eSPI
- Teensy SD file library to load the fonts
The MicroTeX library was lazily modified to correctly load fonts and handle cases where exceptions were deliberately thrown and caught. Then to get it to compile with gcc-arm-none-eabi it also needed flags -std=gnu++17 -fno-exceptions -fno-rtti. A custom linker script for the teensy was also made as the program compiled to just over 1MB wouldnt fit on the teensys ITCM memory.
