Day 27 complete.

handmade.c

@@ -37,6 +37,64 @@ static void GameOutputSound(game_state *GameState,
     */
 }
 
+static void ClearBackground(game_offscreen_buffer *Buffer)
+{
+    S32 Width, Height, X;
+
+    Width = Buffer->Width;
+    Height = Buffer->Height;
+
+    for(X = 0; X < Width * Height; X++) {
+        U32 *Pixel = &((U32 *)Buffer->Memory)[X];
+        *Pixel = 0xFFFFFF;
+    }
+}
+
+static S32 RoundF32toS32(F32 Real32)
+{
+    S32 Result = (S32)(Real32 + 0.5f);
+    return Result;
+}
+
+static void DrawRectangle(game_offscreen_buffer *Buffer,
+                          F32 RealMinX, F32 RealMinY,
+                          F32 RealMaxX, F32 RealMaxY,
+                          U32 Color)
+                          /*F32 R, F32 G, F32 B)*/
+{
+    S32 MinX = RoundF32toS32(RealMinX);
+    S32 MinY = RoundF32toS32(RealMinY);
+    S32 MaxX = RoundF32toS32(RealMaxX);
+    S32 MaxY = RoundF32toS32(RealMaxY);
+
+    S32 Width = Buffer->Width;
+    S32 Height = Buffer->Height;
+
+    U8 *Row;
+    S32 Y, X;
+
+    if(MinX < 0)
+        MinX = 0;
+    if(MinY < 0)
+        MinY = 0;
+
+    if(MaxX > Width)
+        MaxX = Width;
+    if(MaxY > Height)
+        MaxY = Height;
+
+    Row = ((U8 *)Buffer->Memory + MinX*Buffer->BytesPerPixel +
+          MinY*Buffer->Pitch);
+    for(Y = MinY; Y < MaxY; Y++) {
+        U32 *Pixel = (U32 *)Row;
+        for(X = MinX; X < MaxX; X++) {
+            *(U32 *)Pixel = Color;
+            Pixel++;
+        }
+        Row += Buffer->Pitch;
+    }
+}
+
 static void RenderRectangle(game_offscreen_buffer *Buffer, S32 MouseX,
                             S32 MouseY)
 {
@@ -87,6 +145,14 @@ void UpdateAndRender(thread_context *Thread, game_memory *Memory,
         }
     }
 
+    DrawRectangle(Buffer, 0.0f, 0.0f, (F32)(Buffer->Width),
+                  (F32)(Buffer->Height), 0x000000);
+    DrawRectangle(Buffer, 10.0f, 10.0f, 20.0f, 20.0f, 0xFFFFFF);
+
+    DrawRectangle(Buffer,
+                  (F32)(Input->MouseX), (F32)(Input->MouseY),
+                  (F32)(Input->MouseX) + 10.0f, (F32)(Input->MouseY) + 10.0f,
+                  0xFF0000);
     GameOutputSound(GameState, SoundBuffer, 400);
 }