Add z buffer

game.cpp

@@ -15,8 +15,21 @@
 
 #define SUBSAMPLE 2
 
+#define SCREEN_WIDTH 110
+#define SCREEN_HEIGHT 88
+
+#define SUBSAMPLED_WIDTH (SCREEN_WIDTH / SUBSAMPLE)
+#define SUBSAMPLED_HEIGHT (SCREEN_HEIGHT / SUBSAMPLE)
+
+#define MIDDLE_ROW (SCREEN_HEIGHT / 2)
+#define MIDDLE_COLUMN (SCREEN_WIDTH / 2)
+
+#define SPRITES 6
+
 Pokitto::Core p;
 
+Unit zBuffer[SUBSAMPLED_WIDTH];
+
 const unsigned char image[] =
 {  32, 32 // width, height
   ,0x12,0x12,0x12,0x12,0x12,0x12,0x00,0x09,0x00,0x12,0x12,0x12,0x12,0x12
@@ -331,15 +344,19 @@ const unsigned char sprite[] =
 
 inline uint8_t sampleImage(const unsigned char *image, Unit x, Unit y)
 {
-  int32_t index = clamp(
+  // TODO: optimize
-    image[1] * ((image[1] * y) / UNITS_PER_SQUARE) +
+
-    (image[0] * x) / UNITS_PER_SQUARE,
+  x = wrap(x,UNITS_PER_SQUARE);
-    0, image[0] * image[1] - 1);
+  y = wrap(y,UNITS_PER_SQUARE);
+
+  int32_t index =
+    image[1] * ((image[1] * y) / UNITS_PER_SQUARE) + (image[0] * x) /
+    UNITS_PER_SQUARE;
 
   return image[2 + index];
 }
 
-void drawSprite(const unsigned char *sprite, int16_t x, int16_t y, int16_t size)
+void drawSprite(const unsigned char *sprite, int16_t x, int16_t y, Unit depth, int16_t size)
 {
   // TODO: optimize
 
@@ -350,10 +367,21 @@ void drawSprite(const unsigned char *sprite, int16_t x, int16_t y, int16_t size)
 
   uint8_t c;
 
-  for (Unit j = 0; j < size; ++j)
+  int16_t jTo = size - max(0,y + size - 88);
+  int16_t iTo = size - max(0,x + size - 110);
+
+  bool mask[SUBSAMPLED_WIDTH];
+
+  for (int i = 0; i < SUBSAMPLED_WIDTH; ++i)
+    mask[i] = zBuffer[i] > depth;
+
+  for (Unit j = max(-1 * y,0); j < jTo; ++j)
   {
-    for (Unit i = 0; i < size; ++i)
+    for (Unit i = max(-1 * x,0); i < iTo; ++i)
     {
+      if (!mask[i])
+        continue;
+
       c = sampleImage(sprite,(i * UNITS_PER_SQUARE) / size,(j * UNITS_PER_SQUARE) / size); 
      
       if (c != 0xff)
@@ -414,6 +442,13 @@ public:
   }
 };
 
+class Sprite
+{
+public:
+  Vector2D mPosition;
+  Unit mHeight;
+};
+
 class Character
 {
 public:
@@ -433,6 +468,7 @@ public:
 
 Character player;
 Level level;
+Sprite sprites[SPRITES];
 
 Unit heightFunc(int16_t x, int16_t y)
 {
@@ -441,6 +477,9 @@ Unit heightFunc(int16_t x, int16_t y)
 
 inline void pixelFunc(PixelInfo pixel)
 {
+  if (pixel.position.y == MIDDLE_ROW)
+    zBuffer[pixel.position.x] = pixel.depth;
+
   uint8_t c;
 
   Unit depth = pixel.depth - UNITS_PER_SQUARE;
@@ -489,25 +528,32 @@ void draw()
 
   render(player.mCamera,heightFunc,pixelFunc,c);
 
-  Vector2D v;
+  for (uint8_t i = 0; i < SPRITES; ++i)
-  v.x = 5 * UNITS_PER_SQUARE;
+  {
-  v.y = 7 * UNITS_PER_SQUARE;
+    PixelInfo pos = mapToScreen(sprites[i].mPosition,sprites[i].mHeight,player.mCamera);
-  PixelInfo pos = mapToScreen(v,UNITS_PER_SQUARE / 4,player.mCamera);
 
     if (pos.depth > 0)
-    drawSprite(sprite,pos.position.x * SUBSAMPLE,pos.position.y,perspectiveScale(32,pos.depth));
+      drawSprite(sprite,pos.position.x * SUBSAMPLE,pos.position.y,
-
+                 pos.depth,perspectiveScale(32,pos.depth));
-  p.display.setColor(rgbToIndex(7,7,3));
+  }
-  p.display.setCursor(1,1);
-  p.display.print(player.mCamera.position.x);
-  p.display.print(" ");
-  p.display.print(player.mCamera.position.y);
-  p.display.print(" ");
-  p.display.print(player.mCamera.direction);
 }
 
 int main()
 {
+  #define placeSprite(I,X,Y,Z)\
+    sprites[I].mPosition.x = X * UNITS_PER_SQUARE + UNITS_PER_SQUARE / 2;\
+    sprites[I].mPosition.y = Y * UNITS_PER_SQUARE + UNITS_PER_SQUARE / 2;\
+    sprites[I].mHeight = Z * UNITS_PER_SQUARE + UNITS_PER_SQUARE / 2;
+
+  placeSprite(0,5,7,0)
+  placeSprite(1,6,7,0)
+  placeSprite(2,5,8,0)
+  placeSprite(3,6,8,0)
+  placeSprite(4,-1,-2,1)
+  placeSprite(5,1,11,1)
+
+  #undef placeSprite
+
   p.begin();
 
   for (uint8_t r = 0; r < 8; ++r)
@@ -541,26 +587,50 @@ int main()
         d.y = d.y > 0 ? step : -step;
       }
 
+      bool strafe = p.aBtn();
+
       if (p.upBtn())
+      {
+        if (strafe)
+          player.mCamera.height += step;
+        else
         {
           player.mCamera.position.x += d.x;
           player.mCamera.position.y += d.y;
         }
+      }
       else if (p.downBtn())
+      {
+        if (strafe)
+          player.mCamera.height -= step;
+        else
         {
           player.mCamera.position.x -= d.x;
           player.mCamera.position.y -= d.y;
         }
+      }
+
+      if (strafe)
+      {
+        d = angleToDirection(player.mCamera.direction + UNITS_PER_SQUARE / 4);
+        d.x = (d.x * step) / UNITS_PER_SQUARE;
+        d.y = (d.y * step) / UNITS_PER_SQUARE;
+      }
+
+      int addition = 0;
 
       if (p.rightBtn())
-        player.mCamera.direction += step2;
+        addition = 1;      
       else if (p.leftBtn())
-        player.mCamera.direction -= step2;
+        addition = -1;
 
-      if (p.aBtn())
+      if (strafe)
-        player.mCamera.height += step;
+      {
-      else if (p.bBtn())
+        player.mCamera.position.x += addition * d.x;
-        player.mCamera.height -= step;
+        player.mCamera.position.y += addition * d.y;
+      }
+      else
+        player.mCamera.direction += addition * step2;
 
       player.mCamera.height =
         max(heightFunc(player.mCamera.position.x / UNITS_PER_SQUARE,player.mCamera.position.y / UNITS_PER_SQUARE) + UNITS_PER_SQUARE / 2,player.mCamera.height);