% Equates in XGod.equ % These constants are passed into Xboard_t to specify highlight levels % highlight_level_t = int % highlight_none = 0 % highlight_move_from = 1 % highlight_move_to = 2 Xboard_t = cluster is create, get_size, reset, set_piece, find_place, make_move % Overview: The Xboard_t date type is used to represent the visual % aspects of the anti-chess board itself to the user. % It maintains all the bitmaps and other visual % elements, such as the row and column labels. Any % "fancy" features, such as shadows and highlights will % be transparently handled by Xboard_t. All procedures % that signals file_not_found leave the Xboard in an % inderterminant state. % Representation rep = record[w: window, bd: bd_t, piece_width, piece_height: pixel, file_prefix: string, x0, y0: pixel] bd_t = array[apc_t] apc_t = array[pc_t] pc_t = record[wi: window_item, fg, bg: color, filename: string] % The representation stores the window to which updates should be % made, the prefix to be added to bitmap names, and a % two-dimensional array to represent what pieces are where on the % board. Each piece stores the window_item to represent it, the % foreground & background for the piece, and the filename of the % piece. % Representation Invariants % * W is a window with a visual representation of an anti-chess % board (after Xboard_t$create returns). This is the window % passed into Xboard_t$create. % * File_prefix is a string representing the path to the bitmaps, % and any prefix characters to add to the beginning of the % bitmap filenames. The value is passed into Xboard_t$create. % * (x0, y0) is the upper-left corner of the playing board, i.e., % the upper-left corner of "a8". % * piece_width and piece_height are the values passed into % Xboard_t$create. % * bd is a two-dimensional array, all dimensions 1 through 8. % * In pc_t, wi is the window_item (bitmap, rectangle, etc.) for % the square on the board. Filename represents the name of the % file in the window_item, and fg and bg are the foreground and % colors of window_item. If filename is an empty string, the % square is just a rectangle and not a bitmap. % Abstraction function % * The window to display in is "w". % * x0, y0, piece_width, and piece_height together determine piece % position: % (x0 + ((piece_width + 2*ShadowWidth) * (col - 1)), % y0 + ((piece_height + 2*ShadowHeight) * (row - 1))) % is the upper-left corner of the piece at col, row. Note that % the piece_width and piece_height are adjusted for any 3D % effects around the bitmaps. % * The structure in bd[row][col] should specify the window_item % at col, row, its foreground and background colors, and the % filename of the bitmap displayed there. If the filename is % the empty string, then the window_item represents an % unoccupied square, and is hence, merely a rectangle. % Random equates: label_width = 40 % Width of the labels label_height = 40 % Height of the labels extra_width = 5 % Space around the board extra_height = 5 % Space around the board letter_width = 10 % Approximate width of a letter letter_height = 18 % Approximate height of a letter % Colors % Colors are stored in an own variable called "color_scheme", with % the following structure: Xboard_color_scheme_t = record[background: three_d_color_t, squares: color_array_t[three_d_color_t], highlight_backgrounds: array[color_array_t[color]], label_color: color, pieces: color_array_t[color]] % Abbreviations for initialization ca = color_array_t[td] cs = Xboard_color_scheme_t td = three_d_color_t acb = array[cac] cac = color_array_t[color] cac_cwb = cac$create_white_black ca_cwbn = ca$create_white_black_none % own color_scheme: cs := % cs${background: td$create("gray50", "gray75", "Black"), % squares: ca_cwbn(td$create("Yellow", "LightYellow", "Brown"), % td$create("Red", "Pink", "IndianRed"), % td$create("gray50", "gray75", "Black")), % highlight_backgrounds: acb$[0: cac_cwb("Yellow", "Red"), % cac_cwb("gray50", "gray50"), % cac_cwb("gray75", "gray25")], % label_color: "White", % pieces: cac_cwb("White", "Black")} own color_scheme: cs := cs${background: td$create("gray50", "gray75", "Black"), squares: ca_cwbn(td$create("goldenrod", "LightYellow", "Brown"), td$create("DarkOrange4", "Pink", "IndianRed"), td$create("gray50", "gray75", "Black")), highlight_backgrounds: acb$[0: cac_cwb("goldenrod", "DarkOrange4"), cac_cwb("gray50", "gray50"), cac_cwb("gray75", "gray25")], label_color: "White", pieces: cac_cwb("White", "Black")} % Color Representation Invariants % * Squares has entries for black, white, and none. % * Highlight_backgrounds has color_array_t entries for black and % white, and the array has entries for all highlight_level % indexes. % * highlight_background[highlight_none][c] = % squares[c].background for c=black, white. % * Pieces has entries for black and white. % Color Abstraction Function % * An inset rectangle that surroundeds the Xboard_t; its colors % are given by "background" % * Squares on the board are raised retangles with colors give by % "squares". The "tabs" on the left and bottom or given by the % "squares" "none" values. % * Highlights are formed by changing the background color of a % square to the value in % highlight_background[highlight_level][square_color]. % * Piece colors are determined from "pieces". create = proc(w: window, board: board_t, piece_width, piece_height: pixel, filename_prefix: string, x0, y0: Pixel) returns (cvt, pixel, pixel) signals (not_possible, bad_color, file_not_found) % requires: x0, y0 are valid coordinates in window w. % Piece_width and piece_height are the width & % height of the bitmaps whose filename is % filename_prefix || "ol_?.bm" and "s_?.bm". % modifies: w % effects: Creates a new Xboard_t for window "w", creating all % the bitmaps, rectangles, etc., for the board, and % returning the new Xboard_t, together with the % total width & height of all the user interface % objects for the Xboard_t. Signals not_possible if % errors occur while creating the interface. % Signals bad_color if an invalid color name is used % within Xboard_t. Signals leave the window in an % indeterminant state. The width and height should % agree with board$get_size for the same piece_width % and piece_height. % Create the basic rep r: rep := rep${w: w, bd: bd_t$create(1), piece_width: piece_width + 2*three_d_bevel_width, piece_height: piece_height + 2*three_d_bevel_width, file_prefix: filename_prefix, x0: x0 + 3 * three_d_bevel_width + label_width + extra_width, y0: y0 + three_d_bevel_width + extra_height} % Create the inset background width, height: int := get_size(piece_width, piece_height) three_d_color_t$make_rectangle(w, color_scheme.background, false, x0, y0, x0 + width - 1, y0 + height - 1) resignal bad_color % Create the board labels % First the row labels for row: int in int$from_to(1, 8) do % Compute coordinates x1: pixel := x0 + extra_width x2: pixel := x1 + three_d_bevel_width + label_width y1: pixel := y0 + r.piece_height * (row - 1) + extra_height y2: pixel := y1 + r.piece_height - three_d_bevel_width % Create the beveled rectangle three_d_color_t$make_rectangle(w, color_scheme.squares[color_t$make_none()], true, x1, y1, x2, y2) resignal bad_color, file_not_found % Put the text in the rectangle text: string := int$unparse(9-row) window$create_text(w, text, (x2 + x1 - letter_width)/2, (y2 + y1 - letter_height)/2, color_scheme.label_color) resignal bad_color end % for % Then the column labels for col: int in int$from_to(1, 8) do % Compute coordinates x1: pixel := r.x0 - three_d_bevel_width + r.piece_width * (col - 1) x2: pixel := x1 + r.piece_width - three_d_bevel_width y1: pixel := y0 + r.piece_height * 8 + extra_height y2: pixel := y1 + label_height - three_d_bevel_width % Create the beveled rectangle three_d_color_t$make_rectangle(w, color_scheme.squares[color_t$make_none()], true, x1, y1, x2, y2) resignal bad_color, file_not_found % Put the text in the rectangle text: string := string$c2s(char$i2c(col - 1 + char$c2i('a'))) window$create_text(w, text, (x2 + x1 - letter_width)/2, (y2 + y1 - letter_height)/2, color_scheme.label_color) resignal bad_color end % for % Create the board interface elements & fill out the array for row: int in int$from_to(1, 8) do % Add a row to the rep bd_row: apc_t := apc_t$create(1) bd_t$addh(r.bd, bd_row) for col: int in int$from_to(1, 8) do % Compute bevel coordinates x1: pixel := r.x0 - three_d_bevel_width + r.piece_width*(col-1) x2: pixel := x1 + r.piece_width - three_d_bevel_width y1: pixel := r.y0 - three_d_bevel_width + r.piece_height*(8-row) y2: pixel := y1 + r.piece_height - three_d_bevel_width % Create bevels pl: place_t := place_t$create(row, col) sq: color_t := get_square_color(pl) three_d_color_t$make_highlight_lines(w, color_scheme.squares[sq], true, x1, y1, x2, y2) resignal bad_color % Create the piece bitmap/rectangle and put it in the rep wi: window_item filename: string x, y: pixel fg, bg: color wi, filename, x, y, fg, bg := create_bitmap(up(r), pl, board[pl], highlight_none) resignal bad_color, file_not_found pc: pc_t := pc_t${wi: wi, fg: fg, bg: bg, filename: filename} % Add the piece apc_t$addh(bd_row, pc) end % for end % for % Return the resulting rep return (r, width, height) end create get_size = proc(piece_width, piece_height: pixel) returns (pixel, pixel) % requires: Piece_width and piece_height are the width and % height of the bitmaps to be used for an Xboard_t. % effects: Returns the total width and height of an Xboard_t % with the given bitmap sizes. return (piece_width * 8 + three_d_bevel_width * 18 + label_width + 2 * extra_width, piece_height * 8 + three_d_bevel_width * 18 + label_height + 2 * extra_height) end get_size reset = proc(Xboard: Xboard_t, board: board_t) signals (bad_color, file_not_found) % modifies: Xboard, window "w" passed into Xboard$create. % effects: Updates the board to reflect "board". Signals % bad_color if an error occurs reading or creating a % bitmap; the state of the window is not guaranteed % in this case. for r: int in int$from_to(1, 8) do for c: int in int$from_to(1, 8) do pl: place_t := place_t$create(r, c) set_piece(Xboard, pl, board[pl], highlight_none) end % for end % for end reset set_piece = proc(Xboard: Xboard_t, place: place_t, piece: piece_t, highlight_level: highlight_level_t) signals (bad_color, file_not_found) % modifies: Xboard, window "w" passed into Xboard$create % effects: Replaces the bitmap (or other window_item) at % "place" with "piece", using the appropriate % background for the square and "highlight_level". % Signals bad_color if the Xboard's internal colors % are invalid. r: rep := down(Xboard) % Get bitmap info for the new piece filename: string x, y: pixel fg, bg: color filename, x, y, fg, bg := get_bitmap_info(Xboard, place, piece, highlight_level) % Check the bitmap file pc: pc_t := r.bd[place.row][place.col] if pc.filename = filename then % Same file: just adjust colors (if necessary). if pc.fg ~= fg then window$set_item_fgcolor(r.w, pc.wi, fg) resignal bad_color end % if if pc.bg ~= bg then window$set_item_bgcolor(r.w, pc.wi, bg) resignal bad_color end % if else wi: window_item wi, filename, x, y, fg, bg := create_bitmap(Xboard, place, piece, highlight_level) resignal bad_color, file_not_found window$destroy_item(r.w, pc.wi) pc.wi := wi end % if % Save the attributes of the window_item to the pc. (wi is % already up-to-date) pc.filename := filename pc.fg := fg pc.bg := bg end set_piece find_place = proc(Xboard: cvt, x, y: pixel) returns (place_t) signals (no_place) % effects: Returns the "place" that contains (x, y), or % signals no_place if (x, y) is not on the board. x := x - Xboard.x0 + three_d_bevel_width y := y - Xboard.y0 + three_d_bevel_width % Check for off of top or left... if (x < 0 cor y < 0) then signal no_place end % if % Get place location x := x / Xboard.piece_width y := y / Xboard.piece_height % Check for off of bottom or right... if (x >= 8 cor y >= 8) then signal no_place end % if % On the board: make a place_t for the place return (place_t$create((7-y)+1, x+1)) end find_place make_move = proc(Xboard: Xboard_t, place_from, place_to: place_t, piece_from, piece_to: piece_t) signals (bad_color, file_not_found) % modifies: Xboard, window "w" passed into Xboard$create. % effects: Moves a piece from place_from to place_to; the % piece starts the motion as a piece_from piece, and % arrives as a piece_to piece. Place_from is left % vacant, and the piece in place_to is replaced by % piece_to. Signals bad_color if any internal % colors are invalid. begin set_piece(Xboard, place_from, piece_t$create(none, color_t$make_none()), highlight_none) set_piece(Xboard, place_to, piece_to, highlight_none) end % begin resignal bad_color, file_not_found end make_move % Internal procedures get_bitmap_info = proc(Xboard: cvt, place: place_t, piece: piece_t, highlight_level: highlight_level_t) returns (string, pixel, pixel, color, color) % effects: Returns the name of the bitmap, or the empty string % for a rectangle, its coordinates, and the % foreground and background colors to represent % "piece" at "place". Does no creation, and does % not depend on the current state of the displayed % board. square_color: color_t := get_square_color(place) x, y: pixel := get_place_location(up(Xboard), place) fg: color bg: color := color_scheme.highlight_backgrounds[highlight_level][square_color] filename: string if color_t$is_none(piece.color) then fg := bg filename := "" else fg := color_scheme.pieces[piece.color] filename := string$c2s(piece_t$unparse(piece_t$create(piece.piecetype, color_t$make_black()))) if (fg = bg) then % Make a rudimentary effort to fix up color-on-same-color if (fg = "Black") then fg := "Black" else fg := "White" end % if filename := "ol_" || filename else filename := "s_" || filename end % if filename := Xboard.file_prefix || filename || ".bm" end % if return (filename, x, y, fg, bg) end get_bitmap_info create_bitmap = proc(Xboard: Xboard_t, place: place_t, piece: piece_t, highlight_level: highlight_level_t) returns (window_item, string, pixel, pixel, color, color) signals (bad_color, file_not_found) % modifies: Window "w" passed into Xboard$create % effects: Creates and returns a bitmap for "piece" at "place" % with highlight "highlight_level". Does not % destroy the bitmap underneath and does not keep % any knowledge of having created the bitmap; the % ownership of the bitmap is transferred entirely to % the caller of this procedure. Note that a % rectangle may be returned. Signals bad_color as % appropriate, not changing the state of "w" if % anything is signalled. Also returns the % coordinates of the upper-left corner of the bitmap % and the foreground and background colors. filename: string x, y: pixel fg, bg: color filename, x, y, fg, bg := get_bitmap_info(Xboard, place, piece, highlight_level) wi: window_item if filename = "" then wi := window$create_rectangle(down(Xboard).w, x, y, x + down(Xboard).piece_width - 2*three_d_bevel_width - 1, y + down(Xboard).piece_height - 2*three_d_bevel_width - 1, bg, bg) resignal bad_color else wi := window$create_bitmap(down(Xboard).w, filename, x, y, fg, bg) resignal bad_color except when bad_file: signal file_not_found end % except end % if return (wi, filename, x, y, fg, bg) end create_bitmap get_square_color = proc(place: place_t) returns (color_t) % effects: Returns the background color of the square at place. if int$mod(place.row + place.col, 2) = 1 then return (color_t$make_white()) else return (color_t$make_black()) end % if end get_square_color get_place_location = proc(Xboard: cvt, place: place_t) returns (pixel, pixel) % effects: Returns the upper-left corner coordinates of the % bitmap for "place". x: pixel := Xboard.x0 + Xboard.piece_width * (place.col - 1) y: pixel := Xboard.y0 + Xboard.piece_height * (8 - place.row) return (x, y) end get_place_location end Xboard_t