diff --git a/README.md b/README.md
index 3cf2c29..1ed4daf 100644
--- a/README.md
+++ b/README.md
@@ -48,18 +48,19 @@ features
 - **Pure C99**, tested to run as C++ as well.
 - Optional framework **functions that handle the whole rendering**.
 - Still **flexible** -- pixels are left for you to draw in any way you want.
-- **Tested on multiple platforms**:
+- **Tested on many platforms**:
   - PC (little endian, 64bit GNU)
+  - compilers: gcc, clang
   - Emscripten (web browser, JavaScript transpile)
-  - Arduboy
-  - Pokitto
-  - Gamebuino META
+  - Arduboy (only experimental)
+  - Pokitto (32bit resource-limited embedded ARM)
+  - Gamebuino META (32bit resource-limited embedded ARM)
   - TODO: 
     - PowerPC emulator (big endian)
     - Android
     - Windows
 - **Many compile-time options** to tune the performance vs quality.
-- **Well commented** and formatted code. Automatic documentation (comments + provided Doxyfile).
+- **Well commented** and formatted code, with examples. Automatic documentation (comments + provided Doxyfile).
 - Completely **free of legal restrictions**, do literally anything you want.
 
 **NOTE**: Backwards compatibility isn't a goal of this libraray. It is meant to
@@ -72,17 +73,14 @@ how to use
 
 **Don't forget to compile with -O3!** This drastically improves performance.
 
-For start take a look at the [testTerminal.c](https://gitlab.com/drummyfish/raycastlib/blob/master/programs/testTerminal.c) program.
-It is only a little bit more complex than a simple hello world.
-
-For more examples see the other files, plus my [Pokitto demos](https://gitlab.com/drummyfish/Pokitto-Raycasting) repository,
-which contains some better documented example code, including a [very simple hello world](https://gitlab.com/drummyfish/Pokitto-Raycasting/blob/master/helloRay.cpp).
+For start take a look at the [helloWorld.c](https://gitlab.com/drummyfish/raycastlib/blob/master/programs/helloWorld.c) program and other examples.
+For more examples see my [Pokitto demos](https://gitlab.com/drummyfish/Pokitto-Raycasting) repository.
 
 Also see **the library code itself**, it is meant to be self-documenting -- you'll find the description of a lot of things at the start of the file.
 
 The basic philosophy is:
 
-- The library implements only a rendering back-end, it doesn't perform any drawing to the actual screen,
+- The library implements only a **rendering back-end**, it doesn't perform any drawing to the actual screen,
   hence there is no dependency on any library such as OpenGL or SDL. It just calls your front-end function
   and tells you which pixels you should write. How you do it is up to you.
 - Before including the header, define `RCL_PIXEL_FUNCTION` to the name of a function you will use to
@@ -101,15 +99,6 @@ The basic philosophy is:
   has a side length of `RCL_UNITS_PER_SQUARE` units. Numbers are normalized by this constant, so e.g.
   the sin function returns a value from `-RCL_UNITS_PER_SQUARE` to `RCL_UNITS_PER_SQUARE`.
 
-TODO
-----
-
-- Transparency (conditional ray passing through).
-- Doors in the middle of squares.
-- Rolling doors for `RCL_renderComplex`.
-- Possibly merge all rendering functions into one.
-- Fix rendering bug that happens at the boundary of positive and negative square coords.
-
 license
 -------
 
diff --git a/programs/make.sh b/programs/make.sh
index 012f97e..b41a90b 100755
--- a/programs/make.sh
+++ b/programs/make.sh
@@ -1,8 +1,27 @@
 #!/bin/bash
 
+# Make script for raycastlib programs.
+# by drummyfish
+# released under CC0 1.0, public domain
+
 if [ "$#" -ne 1 ]; then
   echo "ERROR: expecting one argument, the name of program without extension (e.g. \"helloWorld\")"
   exit 0
 fi
 
-clear; clear; g++ -x c -g -fmax-errors=5 -pedantic -Wall -Wextra -o $1 $1.c -lSDL2 2>&1 >/dev/null && ./$1
+link=""
+
+if [ "$1" = "testSDL" ]; then
+  link="-lSDL2"
+fi
+
+clear
+clear
+
+flags="-x c -g -O3 -pedantic -Wall -Wextra -o $1 $1.c ${link}"
+compiler=gcc
+#compiler=clang
+
+echo "making:" ${compiler} ${flags}
+
+${compiler} ${flags} > /dev/null 2>&1 && ./$1
diff --git a/programs/test.c b/programs/test.c
index c60f8e8..54dee80 100644
--- a/programs/test.c
+++ b/programs/test.c
@@ -1,5 +1,6 @@
 /**
-  Tests for raycastlib.
+  General tests for raycastlib, use to test new version, different platforms
+  etc.
 
   license: CC0
 */
@@ -477,7 +478,7 @@ int main()
     RCL_Unit scaled = RCL_perspectiveScaleHorizontal(size,distance);
     RCL_Unit distance2 = RCL_perspectiveScaleHorizontalInverse(size,scaled);
 
-    if (RCL_absVal(distance - distance2 > 2))
+    if (RCL_abs(distance - distance2 > 2))
       printf("ERROR: distance: %d, distance inverse: %d\n",distance,distance2);
   }
 
@@ -552,9 +553,6 @@ int main()
   t = measureTime(benchmarkRender);
   printf("render 100 times: %ld ms\n",t);
 
-  printf("\n"); 
-  printProfile();
-
   printf("\n===== all OK =====\n");
 
   return 0;
diff --git a/programs/testTerminal.c b/programs/testTerminal.c
index 2ea5a09..3ad3e58 100644
--- a/programs/testTerminal.c
+++ b/programs/testTerminal.c
@@ -1,5 +1,6 @@
 /*
-  Raycasting terminal test.
+  Raycasting terminal test. Renders a raycasted animation in the terminal as
+  ASCII.
 
   author: Miloslav Ciz
   license: CC0 1.0, public domain
@@ -79,8 +80,7 @@ void pixelFunc(RCL_PixelInfo *p)
     switch (p->hit.direction)
     {
       case 0:  shade += 2;
-      case 1:  shade += p->texCoords.y / 512;
-               c = asciiShades[shade];
+      case 1:  c = asciiShades[shade];
                break;
       case 2:  c = 'o'; break;
       case 3:
diff --git a/todo.txt b/todo.txt
new file mode 100644
index 0000000..856313c
--- /dev/null
+++ b/todo.txt
@@ -0,0 +1,5 @@
+- Transparency (conditional ray passing through).
+- Doors in the middle of squares.
+- Rolling doors for `RCL_renderComplex`. Or perhaps remove rolling doors (KISS)
+- Possibly merge all rendering functions into one.
+- Fix rendering bug that happens at the boundary of positive and negative square coords.