From 5fb61e409893ef18db5d9cec9fdfcc3fe37da520 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miloslav=20=C4=8C=C3=AD=C5=BE?= <tastyfish@seznam.cz>
Date: Sun, 29 Dec 2019 21:09:50 +0100
Subject: [PATCH] Blur background

---
 main.c     | 38 ++++++++++++++++++++++++++++++++++----
 settings.h |  7 ++++++-
 2 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/main.c b/main.c
index 67877dd..e45252c 100755
--- a/main.c
+++ b/main.c
@@ -622,6 +622,22 @@ void SFG_recompurePLayerDirection()
     / RCL_UNITS_PER_SQUARE; 
 }
 
+#if SFG_BACKGROUND_BLUR != 0
+uint8_t SFG_backgroundBlurIndex = 0;
+
+SFG_PROGRAM_MEMORY int8_t SFG_backgroundBlurOffsets[9] =
+  {0  * SFG_BACKGROUND_BLUR,
+   16 * SFG_BACKGROUND_BLUR,
+   7  * SFG_BACKGROUND_BLUR,
+   17 * SFG_BACKGROUND_BLUR,
+   1  * SFG_BACKGROUND_BLUR,
+   4  * SFG_BACKGROUND_BLUR,
+   15 * SFG_BACKGROUND_BLUR,
+   9  * SFG_BACKGROUND_BLUR,
+   7  * SFG_BACKGROUND_BLUR
+  };
+#endif
+
 void SFG_initPlayer()
 {
   RCL_initCamera(&SFG_player.camera);
@@ -729,10 +745,24 @@ void SFG_pixelFunc(RCL_PixelInfo *pixel)
   }
   else
   {
-    color = SFG_getTexel(SFG_backgroundImages[0],
-    SFG_backgroundScaleMap[(pixel->position.x * SFG_RAYCASTING_SUBSAMPLE + SFG_backgroundScroll) % SFG_GAME_RESOLUTION_Y],
-                                                                   // ^ TODO: get rid of mod?
-    SFG_backgroundScaleMap[pixel->position.y]);
+
+    color = SFG_getTexel(
+      SFG_backgroundImages[0],
+      SFG_backgroundScaleMap[((pixel->position.x 
+#if SFG_BACKGROUND_BLUR != 0
+        + SFG_backgroundBlurOffsets[SFG_backgroundBlurIndex]
+#endif
+        ) * SFG_RAYCASTING_SUBSAMPLE + SFG_backgroundScroll) % SFG_GAME_RESOLUTION_Y],                                                               
+      (SFG_backgroundScaleMap[(pixel->position.y          // ^ TODO: get rid of mod?
+#if SFG_BACKGROUND_BLUR != 0
+        + SFG_backgroundBlurOffsets[SFG_backgroundBlurIndex + 1]
+#endif
+        ) % SFG_GAME_RESOLUTION_Y ])                                               
+      );
+
+#if SFG_BACKGROUND_BLUR != 0
+    SFG_backgroundBlurIndex = (SFG_backgroundBlurIndex + 1) % 0x07;
+#endif
   }
 
   RCL_Unit screenX = pixel->position.x * SFG_RAYCASTING_SUBSAMPLE;
diff --git a/settings.h b/settings.h
index 8263bf9..81492a9 100644
--- a/settings.h
+++ b/settings.h
@@ -151,7 +151,12 @@
   for distance. Higher value may decrease performance a tiny bit, but things
   will react more quickly and appear less "out of thin air".
 */
-
 #define SFG_ELEMENT_DISTANCES_CHECKED_PER_FRAME 8
 
+/**
+  Says the intensity of background image blur. 0 means no blur, improves
+  performance and lowers memory usage.
+*/
+#define SFG_BACKGROUND_BLUR 0
+
 #endif // guard