Add --min-y and --max-y options

README.rst

@@ -53,6 +53,15 @@ drawplayers:
 draworigin:
     Draw origin indicator, `--draworigin`
 
+noshading:
+    Don't draw shading on nodes, `--noshading`
+
+min-y:
+    Don't draw nodes below this y value, `--min-y -25`
+
+max-y:
+    Don't draw nodes above this y value, `--max-y 75`
+
 geometry:
     Limit area to specific geometry, `--geometry -800:-800+1600+1600`
 

TileGenerator.cpp

@@ -102,6 +102,8 @@ TileGenerator::TileGenerator():
 	m_xMax(INT_MIN),
 	m_zMin(INT_MAX),
 	m_zMax(INT_MIN),
+	m_yMin(-30000),
+	m_yMax(30000),
 	m_geomX(-50),
 	m_geomY(-50),
 	m_geomX2(50),
@@ -213,6 +215,16 @@ void TileGenerator::setGeometry(int x, int y, int w, int h)
 	}
 }
 
+void TileGenerator::setMinY(int y)
+{
+	m_yMin = y;
+}
+
+void TileGenerator::setMaxY(int y)
+{
+	m_yMax = y;
+}
+
 void TileGenerator::parseColorsFile(const std::string &fileName)
 {
 	ifstream in;
@@ -295,6 +307,12 @@ void TileGenerator::loadBlocks()
 				if (pos.x < m_geomX || pos.x >= m_geomX2 || pos.z < m_geomY || pos.z >= m_geomY2) {
 					continue;
 				}
+				if (pos.y < m_yMin) {
+					continue;
+				}
+				if (pos.y > m_yMax) {
+					continue;
+				}
 				if (pos.x < m_xMin) {
 					m_xMin = pos.x;
 				}
@@ -479,7 +497,9 @@ inline void TileGenerator::renderMapBlock(const unsigned_string &mapBlock, const
 				continue;
 			}
 			int imageX = getImageX(xBegin + x);
-			for (int y = 15; y >= 0; --y) {
+			int minY = (pos.y * 16 > m_yMin) ? 0 : m_yMin - pos.y * 16;
+			int maxY = (pos.y * 16 < m_yMax) ? 15 : m_yMax - pos.y * 16;
+			for (int y = maxY; y >= minY; --y) {
 				int position = x + (y << 4) + (z << 8);
 				int content = readBlockContent(mapData, version, position);
 				if (content == m_blockIgnoreId || content == m_blockAirId) {

TileGenerator.h

@@ -77,6 +77,8 @@ public:
 	void setDrawScale(bool drawScale);
 	void setShading(bool shading);
 	void setGeometry(int x, int y, int w, int h);
+	void setMinY(int y);
+	void setMaxY(int y);
 	void parseColorsFile(const std::string &fileName);
 	void generate(const std::string &input, const std::string &output);
 
@@ -117,6 +119,8 @@ private:
 	int m_xMax;
 	int m_zMin;
 	int m_zMax;
+	int m_yMin;
+	int m_yMax;
 	int m_geomX;
 	int m_geomY;
 	int m_geomX2;

mapper.cpp

@@ -51,6 +51,8 @@ int main(int argc, char *argv[])
 		{"drawscale", no_argument, 0, 'S'},
 		{"noshading", no_argument, 0, 'H'},
 		{"geometry", required_argument, 0, 'g'},
+		{"min-y", required_argument, 0, 'a'},
+		{"max-y", required_argument, 0, 'c'},
 	};
 
 	string input;
@@ -65,7 +67,7 @@ int main(int argc, char *argv[])
 		if (c == -1) {
 			if (input.empty() || output.empty()) {
 				usage();
-				return -1;
+				return 0;
 			}
 			break;
 		}
@@ -104,6 +106,22 @@ int main(int argc, char *argv[])
 			case 'H':
 				generator.setShading(false);
 				break;
+			case 'a': {
+					istringstream iss;
+					iss.str(optarg);
+					int miny;
+					iss >> miny;
+					generator.setMinY(miny);
+				}
+				break;
+			case 'c': {
+					istringstream iss;
+					iss.str(optarg);
+					int maxy;
+					iss >> maxy;
+					generator.setMaxY(maxy);
+				}
+				break;
 			case 'g': {
 					istringstream geometry;
 					geometry.str(optarg);
@@ -112,13 +130,13 @@ int main(int argc, char *argv[])
 					geometry >> x >> c >> y >> w >> h;
 					if (geometry.fail() || c != ':' || w < 1 || h < 1) {
 						usage();
-						exit(-1);
+						exit(1);
 					}
 					generator.setGeometry(x, y, w, h);
 				}
 				break;
 			default:
-				abort();
+				exit(1);
 		}
 	}
 	try {