From c27c3533f72e0721354c82e16472aa3ef7839bf7 Mon Sep 17 00:00:00 2001
From: Nick Parker <nick@nickbp.com>
Date: Thu, 8 Dec 2011 19:42:59 -0800
Subject: [PATCH] make the position math steps more visible to the outside.
 when next position is going to be filling the screen, just maximize the
 window.

---
 src/grid.cpp     |  22 +-
 src/position.cpp | 785 +++++++++++++++++++++++------------------------
 src/position.h   |  27 +-
 src/window.cpp   |  40 ++-
 src/window.h     |   1 +
 5 files changed, 457 insertions(+), 418 deletions(-)

diff --git a/src/grid.cpp b/src/grid.cpp
index d408049..445b932 100644
--- a/src/grid.cpp
+++ b/src/grid.cpp
@@ -21,6 +21,8 @@
 #include "position.h"
 #include "window.h"
 
+#include "config.h"
+
 bool grid::set_position(POS pos) {
 	//initializes to the currently active window
 	ActiveWindow win;
@@ -34,7 +36,23 @@ bool grid::set_position(POS pos) {
 	//using the requested position and current dimensions,
 	//calculate and set new dimensions
 	PositionCalc calc(viewport, cur_dim);
-	
+
+	State cur_state, next_state;
+	if (!calc.CurState(cur_state) ||
+			!calc.NextState(cur_state, pos, next_state)) {
+		return false;
+	}
+
+	//if we're going to be filling the screen anyway, just maximize
+	if (next_state.pos == grid::POS_CENTER &&
+		next_state.mode == grid::MODE_THREE_COL_L) {
+		if (win.Maximize()) {
+			return true;
+		}
+		ERROR_DIR("Maximizing window failed, falling back to filling screen.");
+	}
+
 	Dimensions next_dim;
-	return calc.NextPos(pos, next_dim) && win.MoveResize(next_dim);
+	return calc.StateToDim(next_state, next_dim) &&
+		win.MoveResize(next_dim);
 }
diff --git a/src/position.cpp b/src/position.cpp
index e38f3cf..afcd917 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -20,21 +20,15 @@
 #include "config.h"
 
 namespace {
-	enum MODE {
-		MODE_UNKNOWN,
-		MODE_TWO_COL,// 2x2 (not applicable for center col positions)
-		MODE_THREE_COL_S,// 3x2 small: each position filling 1 column
-		MODE_THREE_COL_L// 3x2 large: sides filling 2 columns and center filling full width
-	};
-	inline const char* mode_str(MODE mode) {
+	inline const char* mode_str(grid::MODE mode) {
 		switch (mode) {
-		case MODE_UNKNOWN:
+		case grid::MODE_UNKNOWN:
 			return "UNKNOWN";
-		case MODE_TWO_COL:
+		case grid::MODE_TWO_COL:
 			return "TWO_COL";
-		case MODE_THREE_COL_S:
+		case grid::MODE_THREE_COL_S:
 			return "THREE_COL_S";
-		case MODE_THREE_COL_L:
+		case grid::MODE_THREE_COL_L:
 			return "THREE_COL_L";
 		default:
 			break;
@@ -42,205 +36,6 @@ namespace {
 		return "???";
 	}
 
-	struct State {
-		grid::POS pos;
-		MODE mode;
-	};
-
-	// given window's state, calculate its dimensions.
-	// could have some kind of fancy autogeneration here,
-	// but there's a very finite number of possible positions (for now?)
-	bool calculate_state(const Dimensions& viewport,
-			const State& state, Dimensions& window_out) {
-		bool ret = true;
-		long rel_x = 0, rel_y = 0;//coordinates relative to viewport
-		switch (state.mode) {
-		case MODE_TWO_COL:
-			switch (state.pos) {
-			case grid::POS_TOP_LEFT:// top left quadrant
-				rel_x = 0;
-				rel_y = 0;
-				window_out.width = viewport.width / 2.;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_TOP_CENTER:// invalid, use mode THREE_COL_S/L
-				return false;
-			case grid::POS_TOP_RIGHT:// top right quadrant
-				rel_x = viewport.width / 2.;
-				rel_y = 0;
-				window_out.width = viewport.width / 2.;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_LEFT:// left half
-				rel_x = 0;
-				rel_y = 0;
-				window_out.width = viewport.width / 2.;
-				window_out.height = viewport.height;
-				break;
-			case grid::POS_CENTER:// invalid, use mode THREE_COL_S/L
-				return false;
-			case grid::POS_RIGHT:// right half
-				rel_x = viewport.width / 2.;
-				rel_y = 0;
-				window_out.width = viewport.width / 2.;
-				window_out.height = viewport.height;
-				break;
-			case grid::POS_BOT_LEFT:// bottom left quadrant
-				rel_x = 0;
-				rel_y = viewport.height / 2.;
-				window_out.width = viewport.width / 2.;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_BOT_CENTER:// invalid, use mode THREE_COL_S/L
-				return false;
-			case grid::POS_BOT_RIGHT:// bottom right quadrant
-				rel_x = viewport.width / 2.;
-				rel_y = viewport.height / 2.;
-				window_out.width = viewport.width / 2.;
-				window_out.height = viewport.height / 2.;
-				break;
-			default:
-				ret = false;
-				break;
-			}
-			break;
-		case MODE_THREE_COL_S:
-			switch (state.pos) {
-			case grid::POS_TOP_LEFT:// top left col
-				rel_x = 0;
-				rel_y = 0;
-				window_out.width = viewport.width / 3.;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_TOP_CENTER:// top center col
-				rel_x = viewport.width / 3.;
-				rel_y = 0;
-				window_out.width = viewport.width / 3.;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_TOP_RIGHT:// top right col
-				rel_x = 2 * viewport.width / 3.;
-				rel_y = 0;
-				window_out.width = viewport.width / 3.;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_LEFT:// left third
-				rel_x = 0;
-				rel_y = 0;
-				window_out.width = viewport.width / 3.;
-				window_out.height = viewport.height;
-				break;
-			case grid::POS_CENTER:// center col
-				rel_x = viewport.width / 3.;
-				rel_y = 0;
-				window_out.width = viewport.width / 3.;
-				window_out.height = viewport.height;
-				break;
-			case grid::POS_RIGHT:// right third
-				rel_x = 2 * viewport.width / 3.;
-				rel_y = 0;
-				window_out.width = viewport.width / 3;
-				window_out.height = viewport.height;
-				break;
-			case grid::POS_BOT_LEFT:// bottom left col
-				rel_x = 0;
-				rel_y = viewport.height / 2.;
-				window_out.width = viewport.width / 3.;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_BOT_CENTER:// bottom center col
-				rel_x = viewport.width / 3.;
-				rel_y = viewport.height / 2.;
-				window_out.width = viewport.width / 3.;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_BOT_RIGHT:// bottom right col
-				rel_x = 2 * viewport.width / 3.;
-				rel_y = viewport.height / 2.;
-				window_out.width = viewport.width / 3.;
-				window_out.height = viewport.height / 2.;
-				break;
-			default:
-				ret = false;
-			}
-			break;
-		case MODE_THREE_COL_L:
-			switch (state.pos) {
-			case grid::POS_TOP_LEFT:// top left two cols
-				rel_x = 0;
-				rel_y = 0;
-				window_out.width = 2 * viewport.width / 3.;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_TOP_CENTER:// top half
-				rel_x = 0;
-				rel_y = 0;
-				window_out.width = viewport.width;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_TOP_RIGHT:// top right two cols
-				rel_x = viewport.width / 3.;
-				rel_y = 0;
-				window_out.width = 2 * viewport.width / 3.;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_LEFT:// left two thirds
-				rel_x = 0;
-				rel_y = 0;
-				window_out.width = 2 * viewport.width / 3.;
-				window_out.height = viewport.height;
-				break;
-			case grid::POS_CENTER:// full screen
-				rel_x = 0;
-				rel_y = 0;
-				window_out.width = viewport.width;
-				window_out.height = viewport.height;
-				break;
-			case grid::POS_RIGHT:// right two thirds
-				rel_x = viewport.width / 3.;
-				rel_y = 0;
-				window_out.width = 2 * viewport.width / 3.;
-				window_out.height = viewport.height;
-				break;
-			case grid::POS_BOT_LEFT:// bottom left two cols
-				rel_x = 0;
-				rel_y = viewport.height / 2.;
-				window_out.width = 2 * viewport.width / 3.;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_BOT_CENTER:// bottom half
-				rel_x = 0;
-				rel_y = viewport.height / 2.;
-				window_out.width = viewport.width;
-				window_out.height = viewport.height / 2.;
-				break;
-			case grid::POS_BOT_RIGHT:// bottom right two cols
-				rel_x = viewport.width / 3.;
-				rel_y = viewport.height / 2.;
-				window_out.width = 2 * viewport.width / 3.;
-				window_out.height = viewport.height / 2.;
-				break;
-			default:
-				ret = false;
-			}
-			break;
-		default:
-			ret = false;
-		}
-		if (ret) {
-			//convert relative pos to absolute:
-			window_out.x = rel_x + viewport.x;
-			window_out.y = rel_y + viewport.y;
-			DEBUG("pos=%s mode=%s -> %ldx %ldy %luw %luh",
-					pos_str(state.pos), mode_str(state.mode),
-					window_out.x, window_out.y,
-					window_out.width, window_out.height);
-		} else {
-			ERROR("Bad pos=%s + mode=%s", pos_str(state.pos), mode_str(state.mode));
-		}
-		return ret;
-	}
-
 #define MAX(a,b) (((a) > (b)) ? (a) : (b))
 	// whether two numbers are 'near' one another, according to a fudge factor.
 	template <typename A, typename B>
@@ -254,223 +49,407 @@ namespace {
 		return ret;
 	}
 #define NEAR(a,b) _near(a, b, #a, #b)
+}
 
-	// given window's dimensions, estimate its state (or unknown+unknown)
-	// (inverse of calculate_state)
-	bool get_current_state(const Dimensions& window,
-			const Dimensions& viewport, State& out) {
-		//get window x/y relative to viewport x/y
-		int rel_x = window.x - viewport.x,
-			rel_y = window.y - viewport.y;
-		out.pos = grid::POS_UNKNOWN;
-		out.mode = MODE_UNKNOWN;
-		if (NEAR(window.width, viewport.width / 2.)) {
-			if (NEAR(window.height, viewport.height / 2.)) {
-				if (NEAR(rel_x, 0)) {
-					if (NEAR(rel_y, 0)) {
-						// top left quadrant
-						out.pos = grid::POS_TOP_LEFT;
-						out.mode = MODE_TWO_COL;
-					} else if (NEAR(rel_y, viewport.height / 2.)) {
-						// bottom left quadrant
-						out.pos = grid::POS_BOT_LEFT;
-						out.mode = MODE_TWO_COL;
-					}
-				} else if (NEAR(rel_x, viewport.width / 2.)) {
-					if (NEAR(rel_y, 0)) {
-						// top right quadrant
-						out.pos = grid::POS_TOP_RIGHT;
-						out.mode = MODE_TWO_COL;
-					} else if (NEAR(rel_y, viewport.height / 2.)) {
-						// bottom right quadrant
-						out.pos = grid::POS_BOT_RIGHT;
-						out.mode = MODE_TWO_COL;
-					}
+/* given window's dimensions, estimate its state (or unknown+unknown)
+   (inverse of StateToDim) */
+bool PositionCalc::CurState(State& out) {
+	//get window x/y relative to viewport x/y
+	int rel_x = window.x - viewport.x,
+		rel_y = window.y - viewport.y;
+	out.pos = grid::POS_UNKNOWN;
+	out.mode = grid::MODE_UNKNOWN;
+	if (NEAR(window.width, viewport.width / 2.)) {
+		if (NEAR(window.height, viewport.height / 2.)) {
+			if (NEAR(rel_x, 0)) {
+				if (NEAR(rel_y, 0)) {
+					// top left quadrant
+					out.pos = grid::POS_TOP_LEFT;
+					out.mode = grid::MODE_TWO_COL;
+				} else if (NEAR(rel_y, viewport.height / 2.)) {
+					// bottom left quadrant
+					out.pos = grid::POS_BOT_LEFT;
+					out.mode = grid::MODE_TWO_COL;
 				}
-			} else if (NEAR(window.height, viewport.height) &&
-					NEAR(rel_y, 0)) {
-				if (NEAR(rel_x, 0)) {
-					// left half
-					out.pos = grid::POS_LEFT;
-					out.mode = MODE_TWO_COL;
-				} else if (NEAR(rel_x, viewport.width / 2.)) {
-					// right half
-					out.pos = grid::POS_RIGHT;
-					out.mode = MODE_TWO_COL;
+			} else if (NEAR(rel_x, viewport.width / 2.)) {
+				if (NEAR(rel_y, 0)) {
+					// top right quadrant
+					out.pos = grid::POS_TOP_RIGHT;
+					out.mode = grid::MODE_TWO_COL;
+				} else if (NEAR(rel_y, viewport.height / 2.)) {
+					// bottom right quadrant
+					out.pos = grid::POS_BOT_RIGHT;
+					out.mode = grid::MODE_TWO_COL;
 				}
 			}
-		} else if (NEAR(window.width, viewport.width / 3.)) {
-			if (NEAR(window.height, viewport.height / 2.)) {
-				if (NEAR(rel_x, 0)) {
-					if (NEAR(rel_y, 0)) {
-						// top left col
-						out.pos = grid::POS_TOP_LEFT;
-						out.mode = MODE_THREE_COL_S;
-					} if (NEAR(rel_y, viewport.height / 2.)) {
-						// bottom left col
-						out.pos = grid::POS_BOT_LEFT;
-						out.mode = MODE_THREE_COL_S;
-					}
-				} else if (NEAR(rel_x, viewport.width / 3.)) {
-					if (NEAR(rel_y, 0)) {
-						// top center col
-						out.pos = grid::POS_TOP_CENTER;
-						out.mode = MODE_THREE_COL_S;
-					} else if (NEAR(rel_y, viewport.height / 2.)) {
-						// bottom center col
-						out.pos = grid::POS_BOT_CENTER;
-						out.mode = MODE_THREE_COL_S;
-					}
-				} else if (NEAR(rel_x, 2 * viewport.width / 3.)) {
-					if (NEAR(rel_y, 0)) {
-						// top right col
-						out.pos = grid::POS_TOP_RIGHT;
-						out.mode = MODE_THREE_COL_S;
-					} else if (NEAR(rel_y, viewport.height / 2.)) {
-						// bottom right col
-						out.pos = grid::POS_BOT_RIGHT;
-						out.mode = MODE_THREE_COL_S;
-					}
-				}
-			} else if (NEAR(window.height, viewport.height) &&
-					NEAR(rel_y, 0)) {
-				if (NEAR(rel_x, 0)) {
-					// left col
-					out.pos = grid::POS_LEFT;
-					out.mode = MODE_THREE_COL_S;
-				} else if (NEAR(rel_x, viewport.width / 3.)) {
-					// center col
-					out.pos = grid::POS_CENTER;
-					out.mode = MODE_THREE_COL_S;
-				} else if (NEAR(rel_x, 2 * viewport.width / 3.)) {
-					// right col
-					out.pos = grid::POS_RIGHT;
-					out.mode = MODE_THREE_COL_S;
-				}
+		} else if (NEAR(window.height, viewport.height) &&
+				NEAR(rel_y, 0)) {
+			if (NEAR(rel_x, 0)) {
+				// left half
+				out.pos = grid::POS_LEFT;
+				out.mode = grid::MODE_TWO_COL;
+			} else if (NEAR(rel_x, viewport.width / 2.)) {
+				// right half
+				out.pos = grid::POS_RIGHT;
+				out.mode = grid::MODE_TWO_COL;
 			}
-		} else if (NEAR(window.width, 2 * viewport.width / 3.)) {
-			if (NEAR(window.height, viewport.height / 2.)) {
-				if (NEAR(rel_x, 0)) {
-					if (NEAR(rel_y, 0)) {
-						// top left two cols
-						out.pos = grid::POS_TOP_LEFT;
-						out.mode = MODE_THREE_COL_L;
-					} else if (NEAR(rel_y, viewport.height / 2.)) {
-						// bottom left two cols
-						out.pos = grid::POS_BOT_LEFT;
-						out.mode = MODE_THREE_COL_L;
-					}
-				} else if (NEAR(rel_x, viewport.width / 3.)) {
-					if (NEAR(rel_y, 0)) {
-						// top right two cols
-						out.pos = grid::POS_TOP_RIGHT;
-						out.mode = MODE_THREE_COL_L;
-					} else if (NEAR(rel_y, viewport.height / 2.)) {
-						// bottom right two cols
-						out.pos = grid::POS_BOT_RIGHT;
-						out.mode = MODE_THREE_COL_L;
-					}
-				}
-			} else if (NEAR(window.height, viewport.height) &&
-					NEAR(rel_y, 0)) {
-				if (NEAR(rel_x, 0)) {
-					// left two cols
-					out.pos = grid::POS_LEFT;
-					out.mode = MODE_THREE_COL_L;
-				} else if (NEAR(rel_x, viewport.width / 3.)) {
-					// right two cols
-					out.pos = grid::POS_RIGHT;
-					out.mode = MODE_THREE_COL_L;
+		}
+	} else if (NEAR(window.width, viewport.width / 3.)) {
+		if (NEAR(window.height, viewport.height / 2.)) {
+			if (NEAR(rel_x, 0)) {
+				if (NEAR(rel_y, 0)) {
+					// top left col
+					out.pos = grid::POS_TOP_LEFT;
+					out.mode = grid::MODE_THREE_COL_S;
+				} if (NEAR(rel_y, viewport.height / 2.)) {
+					// bottom left col
+					out.pos = grid::POS_BOT_LEFT;
+					out.mode = grid::MODE_THREE_COL_S;
 				}
-			}
-		} else if (NEAR(window.width, viewport.width) &&
-				NEAR(rel_x, 0)) {
-			if (NEAR(window.height, viewport.height / 2.)) {
+			} else if (NEAR(rel_x, viewport.width / 3.)) {
 				if (NEAR(rel_y, 0)) {
-					// top half
+					// top center col
 					out.pos = grid::POS_TOP_CENTER;
-					out.mode = MODE_THREE_COL_L;
+					out.mode = grid::MODE_THREE_COL_S;
 				} else if (NEAR(rel_y, viewport.height / 2.)) {
-					// bottom half
+					// bottom center col
 					out.pos = grid::POS_BOT_CENTER;
-					out.mode = MODE_THREE_COL_L;
+					out.mode = grid::MODE_THREE_COL_S;
+				}
+			} else if (NEAR(rel_x, 2 * viewport.width / 3.)) {
+				if (NEAR(rel_y, 0)) {
+					// top right col
+					out.pos = grid::POS_TOP_RIGHT;
+					out.mode = grid::MODE_THREE_COL_S;
+				} else if (NEAR(rel_y, viewport.height / 2.)) {
+					// bottom right col
+					out.pos = grid::POS_BOT_RIGHT;
+					out.mode = grid::MODE_THREE_COL_S;
 				}
-			} else if (NEAR(window.height, viewport.height) &&
-					NEAR(rel_y, 0)) {
-				// full screen
+			}
+		} else if (NEAR(window.height, viewport.height) &&
+				NEAR(rel_y, 0)) {
+			if (NEAR(rel_x, 0)) {
+				// left col
+				out.pos = grid::POS_LEFT;
+				out.mode = grid::MODE_THREE_COL_S;
+			} else if (NEAR(rel_x, viewport.width / 3.)) {
+				// center col
 				out.pos = grid::POS_CENTER;
-				out.mode = MODE_THREE_COL_L;
+				out.mode = grid::MODE_THREE_COL_S;
+			} else if (NEAR(rel_x, 2 * viewport.width / 3.)) {
+				// right col
+				out.pos = grid::POS_RIGHT;
+				out.mode = grid::MODE_THREE_COL_S;
 			}
 		}
-
-		DEBUG("%ldx %ldy %luw %luh -> pos=%s mode=%s",
-				rel_x, rel_y, window.width, window.height,
-				pos_str(out.pos), mode_str(out.mode));
-		return true;
+	} else if (NEAR(window.width, 2 * viewport.width / 3.)) {
+		if (NEAR(window.height, viewport.height / 2.)) {
+			if (NEAR(rel_x, 0)) {
+				if (NEAR(rel_y, 0)) {
+					// top left two cols
+					out.pos = grid::POS_TOP_LEFT;
+					out.mode = grid::MODE_THREE_COL_L;
+				} else if (NEAR(rel_y, viewport.height / 2.)) {
+					// bottom left two cols
+					out.pos = grid::POS_BOT_LEFT;
+					out.mode = grid::MODE_THREE_COL_L;
+				}
+			} else if (NEAR(rel_x, viewport.width / 3.)) {
+				if (NEAR(rel_y, 0)) {
+					// top right two cols
+					out.pos = grid::POS_TOP_RIGHT;
+					out.mode = grid::MODE_THREE_COL_L;
+				} else if (NEAR(rel_y, viewport.height / 2.)) {
+					// bottom right two cols
+					out.pos = grid::POS_BOT_RIGHT;
+					out.mode = grid::MODE_THREE_COL_L;
+				}
+			}
+		} else if (NEAR(window.height, viewport.height) &&
+				NEAR(rel_y, 0)) {
+			if (NEAR(rel_x, 0)) {
+				// left two cols
+				out.pos = grid::POS_LEFT;
+				out.mode = grid::MODE_THREE_COL_L;
+			} else if (NEAR(rel_x, viewport.width / 3.)) {
+				// right two cols
+				out.pos = grid::POS_RIGHT;
+				out.mode = grid::MODE_THREE_COL_L;
+			}
+		}
+	} else if (NEAR(window.width, viewport.width) &&
+			NEAR(rel_x, 0)) {
+		if (NEAR(window.height, viewport.height / 2.)) {
+			if (NEAR(rel_y, 0)) {
+				// top half
+				out.pos = grid::POS_TOP_CENTER;
+				out.mode = grid::MODE_THREE_COL_L;
+			} else if (NEAR(rel_y, viewport.height / 2.)) {
+				// bottom half
+				out.pos = grid::POS_BOT_CENTER;
+				out.mode = grid::MODE_THREE_COL_L;
+			}
+		} else if (NEAR(window.height, viewport.height) &&
+				NEAR(rel_y, 0)) {
+			// full screen
+			out.pos = grid::POS_CENTER;
+			out.mode = grid::MODE_THREE_COL_L;
+		}
 	}
 
-	bool get_next_state(const State& cur, grid::POS req_pos, State& out) {
-		if (req_pos == grid::POS_UNKNOWN) {
-			ERROR("Position '%s' was requested. Internal error?", pos_str(req_pos));
-			return false;// nice to have
-		}
-		if (cur.pos == req_pos) {
-			// position is same, so rotate mode
-			out.pos = cur.pos;
-			switch (cur.pos) {
-			case grid::POS_TOP_CENTER:
-			case grid::POS_CENTER:
-			case grid::POS_BOT_CENTER:
-				// for center col: 3x2L -> 3x2S (-> 3x2L) (no 2x2)
-				switch (cur.mode) {
-				case MODE_THREE_COL_L:
-					out.mode = MODE_THREE_COL_S;
-					break;
-				case MODE_THREE_COL_S:
-				default:
-					out.mode = MODE_THREE_COL_L;
-				}
+	DEBUG("%ldx %ldy %luw %luh -> pos=%s mode=%s",
+			rel_x, rel_y, window.width, window.height,
+			pos_str(out.pos), mode_str(out.mode));
+	return true;
+}
+
+bool PositionCalc::NextState(const State& cur, grid::POS req_pos, State& out) {
+	if (req_pos == grid::POS_UNKNOWN) {
+		ERROR("Position '%s' was requested. Internal error?", pos_str(req_pos));
+		return false;// nice to have
+	}
+	if (cur.pos == req_pos) {
+		// position is same, so rotate mode
+		out.pos = cur.pos;
+		switch (cur.pos) {
+		case grid::POS_TOP_CENTER:
+		case grid::POS_CENTER:
+		case grid::POS_BOT_CENTER:
+			// for center col: 3x2L -> 3x2S (-> 3x2L) (no 2x2)
+			switch (cur.mode) {
+			case grid::MODE_THREE_COL_L:
+				out.mode = grid::MODE_THREE_COL_S;
 				break;
+			case grid::MODE_THREE_COL_S:
 			default:
-				// for everything else: 2x2 -> 3x2L -> 3x2S (-> 2x2)
-				switch (cur.mode) {
-				case MODE_UNKNOWN:
-				case MODE_THREE_COL_L:
-					out.mode = MODE_THREE_COL_S;
-					break;
-				case MODE_TWO_COL:
-					out.mode = MODE_THREE_COL_L;
-					break;
-				case MODE_THREE_COL_S:
-				default:
-					out.mode = MODE_TWO_COL;
-				}
+				out.mode = grid::MODE_THREE_COL_L;
 			}
-		} else {
-			// new position, so start with initial mode
-			out.pos = req_pos;
-			switch (req_pos) {
-			case grid::POS_TOP_CENTER:
-			case grid::POS_CENTER:
-			case grid::POS_BOT_CENTER:
-				// for center col: start with 3x2L
-				out.mode = MODE_THREE_COL_L;
+			break;
+		default:
+			// for everything else: 2x2 -> 3x2L -> 3x2S (-> 2x2)
+			switch (cur.mode) {
+			case grid::MODE_UNKNOWN:
+			case grid::MODE_THREE_COL_L:
+				out.mode = grid::MODE_THREE_COL_S;
+				break;
+			case grid::MODE_TWO_COL:
+				out.mode = grid::MODE_THREE_COL_L;
 				break;
+			case grid::MODE_THREE_COL_S:
 			default:
-				// for everything else: start with 2x2
-				out.mode = MODE_TWO_COL;
+				out.mode = grid::MODE_TWO_COL;
 			}
 		}
-		DEBUG("curpos=%s curmode=%s + reqpos=%s -> pos=%s mode=%s",
-				pos_str(cur.pos), mode_str(cur.mode), pos_str(req_pos),
-				pos_str(out.pos), mode_str(out.mode));
-		return true;
+	} else {
+		// new position, so start with initial mode
+		out.pos = req_pos;
+		switch (req_pos) {
+		case grid::POS_TOP_CENTER:
+		case grid::POS_CENTER:
+		case grid::POS_BOT_CENTER:
+			// for center col: start with 3x2L
+			out.mode = grid::MODE_THREE_COL_L;
+			break;
+		default:
+			// for everything else: start with 2x2
+			out.mode = grid::MODE_TWO_COL;
+		}
 	}
+	DEBUG("curpos=%s curmode=%s + reqpos=%s -> pos=%s mode=%s",
+			pos_str(cur.pos), mode_str(cur.mode), pos_str(req_pos),
+			pos_str(out.pos), mode_str(out.mode));
+	return true;
 }
 
-bool PositionCalc::NextPos(grid::POS request, Dimensions& out) {
-	State cur_state, next_state;
-	return get_current_state(window, viewport, cur_state) &&// window + viewport -> cur_state
-		get_next_state(cur_state, request, next_state) &&// cur_state + request -> next_state
-		calculate_state(viewport, next_state, out);// next_state + viewport -> next_dim
+/* given window's state, calculate its dimensions.
+   could have some kind of fancy autogeneration here,
+   but there's a very finite number of possible positions (for now?) */
+bool PositionCalc::StateToDim(const State& state, Dimensions& out) {
+	bool ret = true;
+	long rel_x = 0, rel_y = 0;//coordinates relative to viewport
+	switch (state.mode) {
+	case grid::MODE_TWO_COL:
+		switch (state.pos) {
+		case grid::POS_TOP_LEFT:// top left quadrant
+			rel_x = 0;
+			rel_y = 0;
+			out.width = viewport.width / 2.;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_TOP_CENTER:// invalid, use mode THREE_COL_S/L
+			return false;
+		case grid::POS_TOP_RIGHT:// top right quadrant
+			rel_x = viewport.width / 2.;
+			rel_y = 0;
+			out.width = viewport.width / 2.;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_LEFT:// left half
+			rel_x = 0;
+			rel_y = 0;
+			out.width = viewport.width / 2.;
+			out.height = viewport.height;
+			break;
+		case grid::POS_CENTER:// invalid, use mode THREE_COL_S/L
+			return false;
+		case grid::POS_RIGHT:// right half
+			rel_x = viewport.width / 2.;
+			rel_y = 0;
+			out.width = viewport.width / 2.;
+			out.height = viewport.height;
+			break;
+		case grid::POS_BOT_LEFT:// bottom left quadrant
+			rel_x = 0;
+			rel_y = viewport.height / 2.;
+			out.width = viewport.width / 2.;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_BOT_CENTER:// invalid, use mode THREE_COL_S/L
+			return false;
+		case grid::POS_BOT_RIGHT:// bottom right quadrant
+			rel_x = viewport.width / 2.;
+			rel_y = viewport.height / 2.;
+			out.width = viewport.width / 2.;
+			out.height = viewport.height / 2.;
+			break;
+		default:
+			ret = false;
+			break;
+		}
+		break;
+	case grid::MODE_THREE_COL_S:
+		switch (state.pos) {
+		case grid::POS_TOP_LEFT:// top left col
+			rel_x = 0;
+			rel_y = 0;
+			out.width = viewport.width / 3.;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_TOP_CENTER:// top center col
+			rel_x = viewport.width / 3.;
+			rel_y = 0;
+			out.width = viewport.width / 3.;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_TOP_RIGHT:// top right col
+			rel_x = 2 * viewport.width / 3.;
+			rel_y = 0;
+			out.width = viewport.width / 3.;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_LEFT:// left third
+			rel_x = 0;
+			rel_y = 0;
+			out.width = viewport.width / 3.;
+			out.height = viewport.height;
+			break;
+		case grid::POS_CENTER:// center col
+			rel_x = viewport.width / 3.;
+			rel_y = 0;
+			out.width = viewport.width / 3.;
+			out.height = viewport.height;
+			break;
+		case grid::POS_RIGHT:// right third
+			rel_x = 2 * viewport.width / 3.;
+			rel_y = 0;
+			out.width = viewport.width / 3;
+			out.height = viewport.height;
+			break;
+		case grid::POS_BOT_LEFT:// bottom left col
+			rel_x = 0;
+			rel_y = viewport.height / 2.;
+			out.width = viewport.width / 3.;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_BOT_CENTER:// bottom center col
+			rel_x = viewport.width / 3.;
+			rel_y = viewport.height / 2.;
+			out.width = viewport.width / 3.;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_BOT_RIGHT:// bottom right col
+			rel_x = 2 * viewport.width / 3.;
+			rel_y = viewport.height / 2.;
+			out.width = viewport.width / 3.;
+			out.height = viewport.height / 2.;
+			break;
+		default:
+			ret = false;
+		}
+		break;
+	case grid::MODE_THREE_COL_L:
+		switch (state.pos) {
+		case grid::POS_TOP_LEFT:// top left two cols
+			rel_x = 0;
+			rel_y = 0;
+			out.width = 2 * viewport.width / 3.;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_TOP_CENTER:// top half
+			rel_x = 0;
+			rel_y = 0;
+			out.width = viewport.width;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_TOP_RIGHT:// top right two cols
+			rel_x = viewport.width / 3.;
+			rel_y = 0;
+			out.width = 2 * viewport.width / 3.;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_LEFT:// left two thirds
+			rel_x = 0;
+			rel_y = 0;
+			out.width = 2 * viewport.width / 3.;
+			out.height = viewport.height;
+			break;
+		case grid::POS_CENTER:// full screen
+			rel_x = 0;
+			rel_y = 0;
+			out.width = viewport.width;
+			out.height = viewport.height;
+			break;
+		case grid::POS_RIGHT:// right two thirds
+			rel_x = viewport.width / 3.;
+			rel_y = 0;
+			out.width = 2 * viewport.width / 3.;
+			out.height = viewport.height;
+			break;
+		case grid::POS_BOT_LEFT:// bottom left two cols
+			rel_x = 0;
+			rel_y = viewport.height / 2.;
+			out.width = 2 * viewport.width / 3.;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_BOT_CENTER:// bottom half
+			rel_x = 0;
+			rel_y = viewport.height / 2.;
+			out.width = viewport.width;
+			out.height = viewport.height / 2.;
+			break;
+		case grid::POS_BOT_RIGHT:// bottom right two cols
+			rel_x = viewport.width / 3.;
+			rel_y = viewport.height / 2.;
+			out.width = 2 * viewport.width / 3.;
+			out.height = viewport.height / 2.;
+			break;
+		default:
+			ret = false;
+		}
+		break;
+	default:
+		ret = false;
+	}
+	if (ret) {
+		//convert relative pos to absolute:
+		out.x = rel_x + viewport.x;
+		out.y = rel_y + viewport.y;
+		DEBUG("pos=%s mode=%s -> %ldx %ldy %luw %luh",
+				pos_str(state.pos), mode_str(state.mode),
+				out.x, out.y, out.width, out.height);
+	} else {
+		ERROR("Bad pos=%s + mode=%s", pos_str(state.pos), mode_str(state.mode));
+	}
+	return ret;
 }
diff --git a/src/position.h b/src/position.h
index b5965bc..309c055 100644
--- a/src/position.h
+++ b/src/position.h
@@ -22,13 +22,38 @@
 #include "pos.h"
 #include "dimensions.h"
 
+namespace grid {
+	enum MODE {
+		MODE_UNKNOWN,
+		MODE_TWO_COL,// 2x2 (not applicable for center col positions)
+		MODE_THREE_COL_S,// 3x2 small: each position filling 1 column
+		MODE_THREE_COL_L// 3x2 large: sides filling 2 columns and center filling full width
+	};
+}
+
+struct State {
+	grid::POS pos;
+	grid::MODE mode;
+};
+
 class PositionCalc {
  public:
 	PositionCalc(const Dimensions& viewport,
 		 const Dimensions& window)
 	 : viewport(viewport), window(window) { }
 
-	bool NextPos(grid::POS request, Dimensions& out);
+	/* Produces an autodetected state of this window using its current
+	 * coordinates. Returns true on success, else false. */
+	bool CurState(State& cur_state);
+
+	/* Given a current state and requested position for the window, calculates
+	 * its next state. Returns true on success, else false. */
+	bool NextState(const State& cur_state, grid::POS req_pos,
+			State& next_state);
+
+	/* Given a state for the window, calculates the dimensions of that position.
+	 * Returns true on success, else false. */
+	bool StateToDim(const State& state, Dimensions& out);
 
  private:
 	const Dimensions viewport, window;
diff --git a/src/window.cpp b/src/window.cpp
index 0694390..2ebf747 100644
--- a/src/window.cpp
+++ b/src/window.cpp
@@ -81,7 +81,7 @@ namespace {
 
 			if (!(types = (Atom*)x11_util::get_property(disp, win,
 									XA_ATOM, "_NET_WM_WINDOW_TYPE", &count))) {
-				ERROR_DIR("couldnt get window types");
+				ERROR_DIR("couldn't get window types");
 				//assume window types are allowed, keep going
 			} else {
 				for (size_t i = 0; i < count; ++i) {
@@ -110,7 +110,7 @@ namespace {
 
 			if (!(states = (Atom*)x11_util::get_property(disp, win,
 									XA_ATOM, "_NET_WM_STATE", &count))) {
-				ERROR_DIR("couldnt get window states");
+				ERROR_DIR("couldn't get window states");
 				//assume window states are allowed, keep going
 			} else {
 				bool has_skip_pager = false, has_skip_taskbar = false;
@@ -228,25 +228,30 @@ namespace {
 						XInternAtom(disp, "_NET_WM_STATE_SHADED", False),
 						XInternAtom(disp, "_NET_WM_STATE_FULLSCREEN", False),
 						SOURCE_INDICATION, 0)) {
-			ERROR_DIR("couldnt unshade/defullscreen");
+			ERROR_DIR("couldn't unshade/defullscreen");
 			return false;
 		}
 		return true;
 	}
 
-	bool demaximize_window(Display* disp, Window win) {
+	bool maximize_window(Display* disp, Window win, bool maximize) {
 		/*
 		  this disagrees with docs, which say that we should be using a
-		  _NET_WM_STATE_DISABLE atom in data[0]. but that apparently doesn't
-		  work in practice, but '0' does. (and '1' works for ENABLE)
+		  _NET_WM_STATE_DISABLE/_ENABLE atom in data[0]. That apparently doesn't
+		  work in practice, but '0'/'1' do.
 		*/
 
+		int val = (maximize) ? 1 : 0;//just to be explicit
 		if (!client_msg(disp, win, "_NET_WM_STATE",
-						0,//1 = enable state(s), 0 = disable state(s)
+						val,//1 = enable state(s), 0 = disable state(s)
 						XInternAtom(disp, "_NET_WM_STATE_MAXIMIZED_VERT", False),
 						XInternAtom(disp, "_NET_WM_STATE_MAXIMIZED_HORZ", False),
 						SOURCE_INDICATION, 0)) {
-			ERROR_DIR("couldnt demaximize");
+			if (maximize) {
+				ERROR_DIR("couldn't maximize");
+			} else {
+				ERROR_DIR("couldn't demaximize");
+			}
 			return false;
 		}
 
@@ -300,7 +305,7 @@ bool ActiveWindow::Sizes(Dimensions& viewport, Dimensions& activewin) const {
 	}
 
 	if (!get_window_size(disp, *win, &activewin, NULL, NULL)) {
-		ERROR_DIR("couldnt get window size");
+		ERROR_DIR("couldn't get window size");
 		return false;
 	}
 
@@ -333,7 +338,7 @@ bool ActiveWindow::MoveResize(const Dimensions& activewin) {
 	}
 
 	//demaximize the window before attempting to move it
-	demaximize_window(disp, *win);//disregard failure
+	maximize_window(disp, *win, false);//disregard failure
 
 	unsigned long new_interior_width = activewin.width - margin_width,
 		new_interior_height = activewin.height - margin_height;
@@ -344,6 +349,17 @@ bool ActiveWindow::MoveResize(const Dimensions& activewin) {
 			margin_width, margin_height,
 			activewin.x, activewin.y, new_interior_width, new_interior_height);
 
-	return XMoveResizeWindow(disp, *win, activewin.x, activewin.y,
-			new_interior_width, new_interior_height) == 0;
+	if (XMoveResizeWindow(disp, *win, activewin.x, activewin.y,
+					new_interior_width, new_interior_height) == 0) {
+		ERROR("MoveResize to %ldx %ldy %luw %luh failed.",
+				activewin.x, activewin.y, new_interior_width, new_interior_height);
+		return false;
+	}
+	return true;
+}
+
+bool ActiveWindow::Maximize() {
+	CHECK_STATE();
+
+	return maximize_window(disp, *win, true);
 }
diff --git a/src/window.h b/src/window.h
index f6da330..dcb679b 100644
--- a/src/window.h
+++ b/src/window.h
@@ -36,6 +36,7 @@ class ActiveWindow {
 
 	bool Sizes(Dimensions& viewport, Dimensions& activewin) const;
 	bool MoveResize(const Dimensions& activewin);
+	bool Maximize();
 
  private:
 	Display* disp;
-- 
2.45.2