From 7124e58b5eb8bdee858f158ce4f235328450d16a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miloslav=20=C4=8C=C3=AD=C5=BE?= <tastyfish@seznam.cz>
Date: Mon, 10 Sep 2018 08:03:09 +0200
Subject: [PATCH] Add texture averaging

---
 demo2.cpp   |  9 ++++++++-
 general.hpp | 17 +++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/demo2.cpp b/demo2.cpp
index c2c93e7..9fb6bac 100644
--- a/demo2.cpp
+++ b/demo2.cpp
@@ -19,6 +19,7 @@ Player player;
 
 #define SHOT_SPEED 5 * UNITS_PER_SQUARE
 #define INFO_BAR_START 70
+#define TEXTURE_DISTANCE (UNITS_PER_SQUARE * 6)
 
 const unsigned char level[] =
 {
@@ -469,6 +470,7 @@ const unsigned char spritePlasma[] =
 };
 
 const unsigned char *textures[] = {texture1, texture2, texture3, texture4};
+unsigned char textureAverageColors[4];
 
 Unit floorHeightAt(int16_t x, int16_t y)
 {
@@ -508,7 +510,9 @@ inline void pixelFunc(PixelInfo pixel)
 
   if (pixel.isWall)
   {
-    c = sampleImage(textures[pixel.hit.type],pixel.hit.textureCoord,pixel.textureCoordY);
+    c = pixel.depth > TEXTURE_DISTANCE ?
+      textureAverageColors[pixel.hit.type] :
+      sampleImage(textures[pixel.hit.type],pixel.hit.textureCoord,pixel.textureCoordY);
 
     if (previousColumn == pixel.position.x)
     {
@@ -562,6 +566,9 @@ int main()
 {
   initGeneral();
 
+  for (uint8_t i = 0; i < 4; ++i)
+    textureAverageColors[i] = computeAverageColor(textures[i]);
+
   cFloor = rgbToIndex(0,1,1);
   cCeiling = rgbToIndex(1,0,1);
 
diff --git a/general.hpp b/general.hpp
index df63115..8b55e08 100644
--- a/general.hpp
+++ b/general.hpp
@@ -236,4 +236,21 @@ void initGeneral()
     zBuffer[i] = 0;  
 }
 
+unsigned char computeAverageColor(const unsigned char *texture)
+{
+  uint32_t sumR = 0;
+  uint32_t sumG = 0;
+  uint32_t sumB = 0;
+  uint32_t pixels = texture[0] * texture[1];
+
+  for (uint16_t i = 0; i < pixels; ++i)
+  {
+    sumR += texture[2 + i] & 0b00000111;
+    sumG += (texture[2 + i] & 0b00111000) >> 3;
+    sumB += (texture[2 + i] & 0b11000000) >> 6;
+  }
+
+  return rgbToIndex(sumR / pixels,sumG / pixels,sumB / pixels);
+}
+
 #endif