From 7cba79252e75089232bf6cd68dfdb9c4175f94fc Mon Sep 17 00:00:00 2001
From: Miloslav Ciz <drummyfish@disroot.org>
Date: Sat, 5 Aug 2023 10:37:06 +0200
Subject: [PATCH] Try to fix a full z buffer bug

---
 mods/full_zbuffer.diff | 100 ++++++++++++++++++++++++++++++++++++++---
 1 file changed, 93 insertions(+), 7 deletions(-)

diff --git a/mods/full_zbuffer.diff b/mods/full_zbuffer.diff
index 9a3ec2f..80d02f4 100644
--- a/mods/full_zbuffer.diff
+++ b/mods/full_zbuffer.diff
@@ -1,9 +1,3 @@
-This mod adds full z-buffer that mostly fixes the incorrect sprite visibility,
-however RAM consumption increases quite a bit. Note that visiblity inaccuracies
-may still occur as e.g. floor depth is not accurate and isn't used, but the game
-generally looks much better. By drummyfish, released under CC0 1.0, public
-domain.
-
 diff --git a/constants.h b/constants.h
 index 956baa0..da72f24 100644
 --- a/constants.h
@@ -18,7 +12,7 @@ index 956baa0..da72f24 100644
  /**
    Step in which walls get higher, in raycastlib units.
 diff --git a/game.h b/game.h
-index 24285cb..f8ef257 100755
+index 991058d..36bba8e 100755
 --- a/game.h
 +++ b/game.h
 @@ -951,6 +951,14 @@ void SFG_pixelFunc(RCL_PixelInfo *pixel)
@@ -76,3 +70,95 @@ index 24285cb..f8ef257 100755
      }
    }
  }
+@@ -4682,7 +4686,7 @@ void SFG_draw()
+   } 
+   else
+   { 
+-    for (int_fast16_t i = 0; i < SFG_Z_BUFFER_SIZE; ++i)
++    for (uint32_t i = 0; i < SFG_Z_BUFFER_SIZE; ++i)
+       SFG_game.zBuffer[i] = 255;
+ 
+     int16_t weaponBobOffset = 0;
+diff --git a/mods/full_zbuffer.diff b/mods/full_zbuffer.diff
+index 9a3ec2f..e69de29 100644
+--- a/mods/full_zbuffer.diff
++++ b/mods/full_zbuffer.diff
+@@ -1,78 +0,0 @@
+-This mod adds full z-buffer that mostly fixes the incorrect sprite visibility,
+-however RAM consumption increases quite a bit. Note that visiblity inaccuracies
+-may still occur as e.g. floor depth is not accurate and isn't used, but the game
+-generally looks much better. By drummyfish, released under CC0 1.0, public
+-domain.
+-
+-diff --git a/constants.h b/constants.h
+-index 956baa0..da72f24 100644
+---- a/constants.h
+-+++ b/constants.h
+-@@ -352,7 +352,7 @@
+-   #define SFG_FONT_SIZE_BIG 1
+- #endif
+- 
+--#define SFG_Z_BUFFER_SIZE SFG_GAME_RESOLUTION_X
+-+#define SFG_Z_BUFFER_SIZE (SFG_GAME_RESOLUTION_X * SFG_GAME_RESOLUTION_Y)
+- 
+- /**
+-   Step in which walls get higher, in raycastlib units.
+-diff --git a/game.h b/game.h
+-index 24285cb..f8ef257 100755
+---- a/game.h
+-+++ b/game.h
+-@@ -951,6 +951,14 @@ void SFG_pixelFunc(RCL_PixelInfo *pixel)
+-       :
+-       SFG_TRANSPARENT_COLOR;
+- 
+-+    uint8_t *zValue = SFG_game.zBuffer +
+-+      pixel->position.y * SFG_GAME_RESOLUTION_X + pixel->position.x;
+-+  
+-+    uint8_t zDistance = SFG_RCLUnitToZBuffer(pixel->depth);
+-+
+-+    if (*zValue >= zDistance)
+-+      *zValue = zDistance;
+-+
+-     shadow = pixel->hit.direction >> 1;
+-   }
+-   else // floor/ceiling
+-@@ -1216,29 +1224,25 @@ void SFG_drawScaledSprite(
+- 
+-   for (int16_t x = x0, u = u0; x <= x1; ++x, ++u)
+-   {
+--    if (SFG_game.zBuffer[x] >= zDistance)
+-+    for (int16_t y = y0, v = v0; y <= y1; ++y, ++v)
+-     {
+--      int8_t columnTransparent = 1;
+-+      uint8_t color =
+-+        SFG_getTexel(image,SFG_game.spriteSamplingPoints[u],
+-+          SFG_game.spriteSamplingPoints[v]);
+- 
+--      for (int16_t y = y0, v = v0; y <= y1; ++y, ++v)
+-+      if (color != SFG_TRANSPARENT_COLOR)
+-       {
+--        uint8_t color =
+--          SFG_getTexel(image,SFG_game.spriteSamplingPoints[u],
+--            SFG_game.spriteSamplingPoints[v]);
+--
+--        if (color != SFG_TRANSPARENT_COLOR)
+--        {
+- #if SFG_DIMINISH_SPRITES
+--          color = palette_minusValue(color,minusValue);
+-+        color = palette_minusValue(color,minusValue);
+- #endif 
+--          columnTransparent = 0;
+-+        uint8_t *zValue = SFG_game.zBuffer + y * SFG_GAME_RESOLUTION_X + x;
+- 
+-+        if (*zValue >= zDistance)
+-+        {       
+-           SFG_setGamePixel(x,y,color);
+-+          *zValue = zDistance;
+-         }
+-       }
+--
+--      if (!columnTransparent)
+--        SFG_game.zBuffer[x] = zDistance;
+-     }
+-   }
+- }