From cfddd24cb98d9fefdfb88460b8be11d983c60343 Mon Sep 17 00:00:00 2001
From: Lephenixnoir <sebastien.mld@numericable.fr>
Date: Wed, 29 May 2019 10:52:52 -0400
Subject: [PATCH] readme: add some basic description and instructions

---
 README.md           | 87 +++++++++++++++++++++++++++++++++++++++++++++
 TODO => TODO.md     |  1 +
 src/platform/sdl2.c |  1 -
 3 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 README.md
 rename TODO => TODO.md (87%)

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..6364cc7
--- /dev/null
+++ b/README.md
@@ -0,0 +1,87 @@
+# Natural display engine with TeX syntax for fx-9860G and fx-CG 50
+
+This library is a customizable 2D math rendering tool for calculators. It can be used to render 2D formulae, either from an existing structure or TeX syntax.
+
+```latex
+\frac{x_7}{\left\{\frac{\frac{2}{3}}{27}\right\}^2}
+```
+
+![Sample on a Graph 35+E II](https://framapic.org/CkFr4ab3FjcZ/bXQg9LyozGqg.jpg)
+
+## Features
+
+* Build formulae from TeX syntax
+* Highly-customizable graphical and layout parameters
+* Drawing is based on a few user-provided primitives (point, line, text size,
+  text)
+* Compatible with fxlib and gint
+
+List of currently supported elements:
+
+* Fractions (`\frac`)
+* Subscripts and superscripts (`_` and `^`)
+* Grouping parentheses, brackets and braces (`\left` and `\right`)
+
+Features that are partially implemented (and what is left to finish them):
+
+* Support for inline style and display style (compute display-style subscript
+  and superscript layout, and expose a parameter)
+* API functions to build TeX objects without a TeX formula (expose functions
+  which are currently in the parser)
+* Full fx-CG 50 support (suitable parenthesis styles)
+
+See the `TODO.md` file for more features to come.
+
+## Building
+
+First specify the platform you want to use :
+
+* `cli` is for command-line tests, with no visualization (PC)
+* `sdl2` is an SDL interface with visualization (font support coming) (PC)
+* `fx9860g` builds the library for fx-9860G targets (calculator)
+* `fxcg50` builds the library for fx-CG 50 targets (calculator)
+
+For calculator platforms, you can use `--toolchain` to specify a different toolchain than the default `sh3eb` and `sh4eb`. The install directory of the library is guessed by asking the compiler, you can override it with `--prefix`.
+
+Example for an SDL setup:
+
+```sh
+% ./configure --platform=sdl2
+```
+
+Then you can make the program, and if it's a calculator library, install it. You can later delete `Makefile.cfg` to reset the configuration, or just reconfigure as needed.
+
+```sh
+% make
+% make install # fx9860g and fxcg50 only
+```
+
+## Using in a program
+
+Before using the library in a program, a configuration step is needed. The library does not have drawing functions and instead requires that you provide some, namely:
+
+* Draw a pixel (`TeX_intf_pixel`)
+* Draw a line (`TeX_intf_line`)
+* Compute the size occupied by a string (`TeX_intf_size`)
+* Render a string (`TeX_intf_text`)
+
+The three rendering functions are available in fxlib; for monospaced fonts the fourth can be implemented trivially. In gint, the four can be defined as wrappers for `dpixel()`, `dline()`, `dsize()` and `dtext()`.
+
+The type of formulae is `TeX_Flow`. To parse and compute the size of a formula, use the `TeX_parse()` functions, which returns a new formula object (or `NULL` if a critical error occurs).
+
+```c
+char *code = "\\frac{x_7}{\\left\\{\\frac{\\frac{2}{3}}{27}\\right\\}^2}";
+struct TeX_Flow *formula = TeX_parse(code);
+```
+
+The size of the formula can be queried through `formula->width` and `formula->height`. To render, specify the location of the top-left corner and the drawing color (which will be passed to all primitives):
+
+```c
+TeX_draw(formula, 0, 0, BLACK);
+```
+
+The same formula can be drawn several times. When it is no longer needed, free it with `TeX_free()`:
+
+```c
+TeX_free(formula);
+```
diff --git a/TODO b/TODO.md
similarity index 87%
rename from TODO
rename to TODO.md
index 70823f0..4b7f87f 100644
--- a/TODO
+++ b/TODO.md
@@ -2,6 +2,7 @@
 *  Write real error messages
 *  Support Unicode symbols (probably requires help from the font side, urgh)
 *  Don't use TEX_LAYOUT_SPACING for everything, just make it the default
+*  Add a parameter to resolve as inline style or display style
 
 *  Add sum and products
 *  Add square roots, and honor TEX_SQRT_SLANTED and TEX_SQRT_BAR_LENGTH
diff --git a/src/platform/sdl2.c b/src/platform/sdl2.c
index d95894a..a43a073 100644
--- a/src/platform/sdl2.c
+++ b/src/platform/sdl2.c
@@ -121,7 +121,6 @@ int main(void)
 
 	struct TeX_Flow *flow = TeX_parse(formula);
 	if(!flow) { puts("parsing error!"); return 1; }
-	size_flow(flow);
 	TeX_debug_flow(flow, 0);
 
 	SDL_SetRenderDrawColor(r, 0xff, 0xff, 0xff, 0xff);