diff --git a/make.sh b/make.sh
index 4ee764c..415a5c6 100755
--- a/make.sh
+++ b/make.sh
@@ -1,2 +1,3 @@
 #!/bin/bash
-clear; clear; g++ -x c -fmax-errors=5 -pedantic -Wall -Wextra -o test test.c 2>&1 >/dev/null && ./test
+#clear; clear; g++ -x c -fmax-errors=5 -pedantic -Wall -Wextra -o test test.c 2>&1 >/dev/null && ./test
+clear; clear; g++ -x c -g -fmax-errors=5 -pedantic -Wall -Wextra -o testSDL testSDL.c -lSDL2 2>&1 >/dev/null && ./testSDL
diff --git a/raycastlib.h b/raycastlib.h
index 6ef4bdc..c173c52 100644
--- a/raycastlib.h
+++ b/raycastlib.h
@@ -336,7 +336,7 @@ Unit clamp(Unit value, Unit valueMin, Unit valueMax)
     return valueMin;
 }
 
-inline Unit absVal(Unit value)
+Unit absVal(Unit value)
 {
   profileCall(absVal);
 
@@ -344,7 +344,7 @@ inline Unit absVal(Unit value)
 }
 
 /// Like mod, but behaves differently for negative values.
-inline Unit wrap(Unit value, Unit mod)
+Unit wrap(Unit value, Unit mod)
 {
   profileCall(wrap);
 
@@ -352,7 +352,7 @@ inline Unit wrap(Unit value, Unit mod)
 }
 
 /// Performs division, rounding down, NOT towards zero.
-inline Unit divRoundDown(Unit value, Unit divisor)
+Unit divRoundDown(Unit value, Unit divisor)
 {
   profileCall(divRoundDown);
 
@@ -702,7 +702,7 @@ Unit _floorCeilFunction(int16_t x, int16_t y)
   return ((f & 0x0000ffff) << 16) | (c & 0x0000ffff);
 }
 
-inline Unit adjustDistance(Unit distance, Camera camera, Ray ray)
+Unit adjustDistance(Unit distance, Camera camera, Ray ray)
 {
   /* FIXME/TODO: The adjusted (=orthogonal, camera-space) distance could
      possibly be computed more efficiently by not computing Euclidean
diff --git a/testSDL.c b/testSDL.c
new file mode 100644
index 0000000..1caf345
--- /dev/null
+++ b/testSDL.c
@@ -0,0 +1,154 @@
+#include <SDL2/SDL.h>
+#include "raycastlib.h"
+#include <stdint.h>
+#include <stdio.h>
+
+#define SCREEN_WIDTH 640
+#define SCREEN_HEIGHT 480
+
+uint32_t *pixels[SCREEN_WIDTH * SCREEN_HEIGHT];
+
+#define KEYS 6
+#define KEY_UP 0
+#define KEY_RIGHT 1
+#define KEY_DOWN 2
+#define KEY_LEFT 3
+#define KEY_Q 4
+#define KEY_W 5
+
+int keys[KEYS];
+
+Camera camera;
+
+#define RGB(r,g,b) (0 | ((r << 16) | (g << 8) | (b)))
+
+Unit heightAt(int16_t x, int16_t y)
+{
+  if (x > 12 || y > 12)
+    return x * y * UNITS_PER_SQUARE;
+
+  return UNITS_PER_SQUARE * ((x < 0 || y < 0 || x > 9 || y > 9) ? 1 : 0);
+}
+
+void drawPixel(PixelInfo *pixel)
+{
+  uint32_t color = RGB(0,255,255);
+
+  if (pixel->isWall)
+    color = 0;
+
+  pixels[pixel->position.y * SCREEN_WIDTH / 2 + pixel->position.x] = color;
+}
+
+void renderFrame()
+{
+  RayConstraints constraints;
+
+  constraints.maxHits = 10;
+  constraints.maxSteps = 20;
+ 
+  render(camera,heightAt,0,0,drawPixel,constraints);
+}
+
+int main()
+{
+camera.position.x = 2 * UNITS_PER_SQUARE;
+camera.position.y = 4 * UNITS_PER_SQUARE;
+camera.height = UNITS_PER_SQUARE;
+camera.shear = 0;
+camera.direction = 0;
+camera.resolution.x = 200;//SCREEN_WIDTH;
+camera.resolution.y = 150;//SCREEN_HEIGHT;
+
+  for (int i = 0; i < KEYS; ++i)
+    keys[i] = 0;
+
+  SDL_Window *window = SDL_CreateWindow("raycasting", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN); 
+  SDL_Renderer *renderer = SDL_CreateRenderer(window,-1,0);
+  SDL_Texture *texture = SDL_CreateTexture(renderer,SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STATIC, SCREEN_WIDTH, SCREEN_HEIGHT);
+  SDL_Surface *screenSurface = SDL_GetWindowSurface(window);
+  SDL_Event event;
+  int running = 1;
+
+  while (running)
+  {
+    renderFrame();
+
+    SDL_UpdateTexture(texture,NULL,pixels,SCREEN_WIDTH * sizeof(uint32_t));
+
+    while (SDL_PollEvent(&event))
+    {
+      int newState = 0;
+      int keyIndex = -1;
+
+      switch (event.type)
+      {
+        case SDL_KEYDOWN:
+          newState = 1;
+        case SDL_KEYUP:
+          switch (event.key.keysym.scancode)
+          {
+            case SDL_SCANCODE_ESCAPE: running = 0; break;
+            case SDL_SCANCODE_UP: keyIndex = KEY_UP; break;
+            case SDL_SCANCODE_RIGHT: keyIndex = KEY_RIGHT; break;
+            case SDL_SCANCODE_DOWN: keyIndex = KEY_DOWN; break;
+            case SDL_SCANCODE_LEFT: keyIndex = KEY_LEFT; break;
+            case SDL_SCANCODE_Q: keyIndex = KEY_Q; break;
+            case SDL_SCANCODE_W: keyIndex = KEY_W; break;
+            default: break;
+          }
+          break;
+
+        case SDL_QUIT:
+          running = 0;
+          break;
+
+        default:
+          break;
+      }
+
+      if (keyIndex >= 0)
+        keys[keyIndex] = newState;
+    }
+
+    int step = 1;
+    int step2 = 1;
+
+    Vector2D direction = angleToDirection(camera.direction);
+
+    direction.x /= 10;
+    direction.y /= 10;
+
+    if (keys[KEY_UP])
+    {
+      camera.position.x += step * direction.x;
+      camera.position.y += step * direction.y;
+    }
+    else if (keys[KEY_DOWN])
+    {
+      camera.position.x -= step * direction.x;
+      camera.position.y -= step * direction.y;
+    }
+
+    if (keys[KEY_Q])
+      camera.height += step * 10;
+    else if (keys[KEY_W])
+      camera.height -= step * 10;
+
+    if (keys[KEY_RIGHT])
+      camera.direction += step2;
+    else if (keys[KEY_LEFT])
+      camera.direction -= step2;
+
+    SDL_RenderClear(renderer);
+    SDL_RenderCopy(renderer,texture,NULL,NULL);
+    SDL_RenderPresent(renderer);
+  }
+
+  SDL_DestroyTexture(texture);
+  SDL_DestroyRenderer(render);
+  SDL_DestroyWindow(window);
+  SDL_Quit();
+
+  return 0;
+}