diff --git a/core_typechecking.cpp b/core_typechecking.cpp
index 301060a..f7a62d3 100644
--- a/core_typechecking.cpp
+++ b/core_typechecking.cpp
@@ -1304,9 +1304,8 @@ resolve_expr(Ast_Expr *ast, Resolve_Flag flags, Ast_Type *compound_context){
         @warning
         We only have one instance of a given Lambda type for example (a: Vec3): Vec3.
         Even though we might have multiple functions with this signature.
-        This creates a problem cause sometimes we can refer to the wrong AST.
-
-        @todo: array of decls in Ast_Type
+        This creates a problem cause sometimes we might refer to the wrong Ast.
+        Need to be careful!!!
         */
         Ast_Lambda *lambda = (Ast_Lambda *)name.type->ast;
         For_Named(lambda->args, lambda_arg){
diff --git a/examples/raymarcher.kl b/examples/raymarcher.kl
index 9f580eb..1fbea64 100644
--- a/examples/raymarcher.kl
+++ b/examples/raymarcher.kl
@@ -1,9 +1,11 @@
 #import "math.kl"
 
-Epsilon :: 0.00001
-Screen  :  *U32
-X       :   S64
-Y       :   S64
+Epsilon  :: 0.00001
+Screen   :  *U32
+X        :   S64
+Y        :   S64
+TotalTime:   F64
+LightPos := Vec3{2,4,2}
 
 SphereSDF :: (pos: Vec3): F32
   result := Vec3_Length(pos) - 1.0
@@ -14,8 +16,14 @@ Raymarcher_Update :: ()
   forward := Vec3{0, 0, -1}
   side := Vec3_Normalize(Vec3_Cross(forward, up))
 
-  light_pos := Vec3{0, 4, 0}
+  LightPos.x = cosf(TotalTime->F32)*4
+  LightPos.y = sinf(TotalTime->F32)*4
 
+  ambient_color := Vec3{0.2,0.2,0.2}
+  diffuse_color := Vec3{0.7,0.2,0.2}
+  specular_color := Vec3{1,1,1}
+  eye := Vec3{0, 0, 2}
+  light_intensity :: 1.2
 
   Xf := 1 / X->F32
   Yf := 1 / Y->F32
@@ -25,14 +33,13 @@ Raymarcher_Update :: ()
         uv := Vec3{x->F32 * Xf * 2 - 1, y->F32 * Yf * 2 - 1, 1.0}
         uv.x *= ratio
         dir := Vec3_Normalize(Vec3{Vec3_Dot(side, uv), Vec3_Dot(up, uv), Vec3_Dot(forward, uv)})
-        pos := Vec3{0, 0, 2}
 
         t: F32
         end: F32 = 100.0
         hit := true
         p: Vec3
         for i := 0, i < 255, i+=1
-          p = Vec3_Add(pos, Vec3_MulF32(dir, t))
+          p = Vec3_Add(eye, Vec3_MulF32(dir, t))
 
           distance := SphereSDF(p)
           if distance < Epsilon
@@ -50,9 +57,28 @@ Raymarcher_Update :: ()
             SphereSDF({p.x, p.y, p.z + Epsilon}) - SphereSDF({p.x, p.y, p.z - Epsilon}),
           })
 
-          diffuse := Vec3_Dot(normal, Vec3_Negate())
+          light_to_point  := Vec3_Normalize(Vec3_Sub(LightPos, p))
+          eye_to_point    := Vec3_Normalize(Vec3_Sub(eye,       p))
+          reflected_light := Vec3_Normalize(Vec3_Reflect(Vec3_Negate(light_to_point), normal))
 
-          Screen[x + y*X] = Vec3_ConvertToARGB(normal)
+          ambient :: 0.2
+          diffuse := Vec3_Dot(normal, light_to_point)
+
+          color := Vec3_MulF32(ambient_color, ambient)
+          if diffuse > Epsilon
+            color = Vec3_Add(color, Vec3_MulF32(diffuse_color, diffuse))
+
+            specular := Vec3_Dot(reflected_light, eye_to_point)
+            if specular > Epsilon
+              specular = specular*specular*specular*specular
+              color = Vec3_Add(color, Vec3_MulF32(specular_color, specular*0.2))
+            color = Vec3_MulF32(color, light_intensity)
+
+          // Gamma correction
+          color.x = sqrtf(color.x)
+          color.y = sqrtf(color.y)
+          color.z = sqrtf(color.z)
+          Screen[x + y*X] = Vec3_ConvertToARGB(color)
 
         else;; Screen[x + y*X] = 0
 
@@ -147,7 +173,6 @@ WinMain :: (hInstance: HINSTANCE, hPrevInstance: HINSTANCE, lpCmdLine: LPSTR, nS
   requested_time_per_frame := 1.0 / 60.0
   frame_start_time := Time()
   frame_number: S64
-  total_time: F64
   for AppIsRunning
     msg: MSG
     for PeekMessageW(&msg, window, 0, 0, PM_REMOVE) > 0
@@ -163,6 +188,8 @@ WinMain :: (hInstance: HINSTANCE, hPrevInstance: HINSTANCE, lpCmdLine: LPSTR, nS
 
 
     frame_time := Time() - frame_start_time
+    frame_number += 1
+    TotalTime += frame_time
     if frame_time < requested_time_per_frame
       if good_scheduling
         time_to_sleep := (requested_time_per_frame - frame_time) * 1000
@@ -176,5 +203,3 @@ WinMain :: (hInstance: HINSTANCE, hPrevInstance: HINSTANCE, lpCmdLine: LPSTR, nS
           new_frame_time = Time() - frame_start_time
 
         frame_time = new_frame_time
-        frame_number += 1
-        total_time += frame_time
\ No newline at end of file
diff --git a/modules/kernel32.kl b/modules/kernel32.kl
index 1ec65e5..c5d7dc9 100644
--- a/modules/kernel32.kl
+++ b/modules/kernel32.kl
@@ -52,6 +52,7 @@ STD_OUTPUT_HANDLE :: 4294967285//(-11)->DWORD
 GetStdHandle  :: #foreign (nStdHandle: DWORD): HANDLE
 WriteConsoleA :: #foreign (hConsoleOutput: HANDLE,lpBuffer: *VOID,nNumberOfCharsToWrite: DWORD,lpNumberOfCharsWritten: LPDWORD,lpReserve: LPVOID): BOOL
 WriteConsoleW :: #foreign (hConsoleOutput: HANDLE,lpBuffer: *VOID,nNumberOfCharsToWrite: DWORD,lpNumberOfCharsWritten: LPDWORD,lpReserve: LPVOID): BOOL
+__debugbreak  :: #foreign ()
 
 GetLastError              :: #foreign (): DWORD
 QueryPerformanceFrequency :: #foreign (lpFrequency: *LARGE_INTEGER): BOOL
diff --git a/modules/math.kl b/modules/math.kl
index 64f6475..da81c21 100644
--- a/modules/math.kl
+++ b/modules/math.kl
@@ -1,12 +1,12 @@
 sqrtf :: #foreign (value: F32): F32
+cosf  :: #foreign (value: F32): F32
+sinf  :: #foreign (value: F32): F32
 
 Vec2I  :: struct;; x: S64; y: S64
 Vec2   :: struct;; x: F32; y: F32
 Vec3   :: struct;; x: F32; y: F32; z: F32
 
-Vec3_Length :: (a: Vec3): F32
-  result := sqrtf(a.x*a.x + a.y*a.y + a.z*a.z)
-  return result
+
 
 Vec3_Cross :: (a: Vec3, b: Vec3): Vec3
   result := Vec3{
@@ -25,6 +25,12 @@ Vec3_Normalize :: (a: Vec3): Vec3
   }
   return result
 
+Vec3_Reflect :: (a: Vec3, normal: Vec3): Vec3
+  an := Vec3_Dot(a, normal)*2
+  result := Vec3_Sub(a, Vec3_MulF32(a, an))
+  return result
+
+
 Vec3_ConvertToARGB :: (a: Vec3): U32
   a.x = F32_Clamp(0, a.x, 1)
   a.y = F32_Clamp(0, a.y, 1)
@@ -35,10 +41,11 @@ Vec3_ConvertToARGB :: (a: Vec3): U32
   result := r | g | b
   return result
 
+Vec3_Length :: (a: Vec3): F32            ;; return sqrtf(a.x*a.x + a.y*a.y + a.z*a.z)
 Vec3_Negate :: (a: Vec3): Vec3           ;; return Vec3{-a.x, -a.y, -a.z}
 Vec3_Dot    :: (a: Vec3, b: Vec3): F32   ;; return a.x*b.x + a.y*b.y + a.z*b.z
 Vec3_Mul    :: (a: Vec3, b: Vec3): Vec3  ;; return Vec3{a.x*b.x, a.y*b.y, a.z*b.z}
-Vec3_MulF32 :: (a: Vec3, b: F32): Vec3   ;; return Vec3{a.x*b, a.y*b, a.z*b}
+Vec3_MulF32 :: (a: Vec3, b: F32) : Vec3  ;; return Vec3{a.x*b, a.y*b, a.z*b}
 Vec3_Add    :: (a: Vec3, b: Vec3): Vec3  ;; return Vec3{a.x+b.x, a.y+b.y, a.z+b.z}
 Vec3_Div    :: (a: Vec3, b: Vec3): Vec3  ;; return Vec3{a.x/b.x, a.y/b.y, a.z/b.z}
 Vec3_Sub    :: (a: Vec3, b: Vec3): Vec3  ;; return Vec3{a.x-b.x, a.y-b.y, a.z-b.z}
@@ -48,6 +55,10 @@ F32_Clamp :: (min: F32, value: F32, max: F32): F32
   if value < min;; return min
   return value
 
+F32_ClampBottom :: (min: F32, value: F32): F32
+  if value < min;; return min
+  return value
+
 F32_Absolute :: (val: F32): F32
   if val < 0;; return -val
   return val
diff --git a/modules/os_windows.kl b/modules/os_windows.kl
index 78eb2a8..f0f7c75 100644
--- a/modules/os_windows.kl
+++ b/modules/os_windows.kl
@@ -51,12 +51,13 @@ WriteConsole :: (string: String16)
   WriteConsoleW(handle, string.str->*void, string.len->DWORD, 0, 0)
 
 PerformanceFrequency: F64
+PerformanceFrequency_S64: S64
 Time :: (): F64
   query: LARGE_INTEGER
-  if !PerformanceFrequency
-    err := QueryPerformanceFrequency(&query)
+  if PerformanceFrequency_S64 == 0
+    err := QueryPerformanceFrequency(&PerformanceFrequency_S64)
     Assert(err != 0)
-    PerformanceFrequency = query->F64
+    PerformanceFrequency = PerformanceFrequency_S64->F64
 
   err := QueryPerformanceCounter(&query)
   Assert(err != 0)