From 90ed6fc732ca667ca970b7c38d39c809e5c3553e Mon Sep 17 00:00:00 2001
From: paramat <paramat@users.noreply.github.com>
Date: Thu, 22 Jun 2017 06:50:22 +0100
Subject: [PATCH] Ores: Make 'absheight' flag non-functional

The 'absheight' flag was added years ago for the floatlands of 'indev'
mapgen (now deleted). The feature mirrored all ore placement around y = 0
to place ores in floatlands.

In MTG we now use dedicated ore registrations for floatlands.

The feature is crude, inflexible, problematic and very rarely used, it
also makes ore vertical range code more complex.
Minetest 0.5 is a good chance to remove the feature.

The flag itself remains to not break flag values.
---
 doc/lua_api.txt |  7 +------
 src/mg_ore.cpp  | 19 ++++---------------
 src/mg_ore.h    |  5 +----
 3 files changed, 6 insertions(+), 25 deletions(-)

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 540bbe118..63d090ebe 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -1076,12 +1076,7 @@ Ore attributes
 See section "Flag Specifier Format".
 
 Currently supported flags:
-`absheight`, `puff_cliffs`, `puff_additive_composition`.
-
-### `absheight`
-Also produce this same ore between the height range of `-y_max` and `-y_min`.
-
-Useful for having ore in sky realms without having to duplicate ore entries.
+`puff_cliffs`, `puff_additive_composition`.
 
 ### `puff_cliffs`
 If set, puff ore generation will not taper down large differences in displacement
diff --git a/src/mg_ore.cpp b/src/mg_ore.cpp
index f959ca9e6..73af2e2e6 100644
--- a/src/mg_ore.cpp
+++ b/src/mg_ore.cpp
@@ -27,7 +27,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 
 FlagDesc flagdesc_ore[] = {
-	{"absheight",                 OREFLAG_ABSHEIGHT},
+	{"absheight",                 OREFLAG_ABSHEIGHT}, // Non-functional
 	{"puff_cliffs",               OREFLAG_PUFF_CLIFFS},
 	{"puff_additive_composition", OREFLAG_PUFF_ADDITIVE},
 	{NULL,                        0}
@@ -87,22 +87,11 @@ void Ore::resolveNodeNames()
 
 size_t Ore::placeOre(Mapgen *mg, u32 blockseed, v3s16 nmin, v3s16 nmax)
 {
-	int in_range = 0;
-
-	in_range |= (nmin.Y <= y_max && nmax.Y >= y_min);
-	if (flags & OREFLAG_ABSHEIGHT)
-		in_range |= (nmin.Y >= -y_max && nmax.Y <= -y_min) << 1;
-	if (!in_range)
+	if (!(nmin.Y <= y_max && nmax.Y >= y_min))
 		return 0;
 
-	int actual_ymin, actual_ymax;
-	if (in_range & ORE_RANGE_MIRROR) {
-		actual_ymin = MYMAX(nmin.Y, -y_max);
-		actual_ymax = MYMIN(nmax.Y, -y_min);
-	} else {
-		actual_ymin = MYMAX(nmin.Y, y_min);
-		actual_ymax = MYMIN(nmax.Y, y_max);
-	}
+	int actual_ymin = MYMAX(nmin.Y, y_min);
+	int actual_ymax = MYMIN(nmax.Y, y_max);
 	if (clust_size >= actual_ymax - actual_ymin + 1)
 		return 0;
 
diff --git a/src/mg_ore.h b/src/mg_ore.h
index 4b052e07a..5aeb3631c 100644
--- a/src/mg_ore.h
+++ b/src/mg_ore.h
@@ -32,14 +32,11 @@ class MMVManip;
 
 /////////////////// Ore generation flags
 
-#define OREFLAG_ABSHEIGHT     0x01
+#define OREFLAG_ABSHEIGHT     0x01 // Non-functional but kept to not break flags
 #define OREFLAG_PUFF_CLIFFS   0x02
 #define OREFLAG_PUFF_ADDITIVE 0x04
 #define OREFLAG_USE_NOISE     0x08
 
-#define ORE_RANGE_ACTUAL 1
-#define ORE_RANGE_MIRROR 2
-
 enum OreType {
 	ORE_SCATTER,
 	ORE_SHEET,