4 files changed, 106 insertions(+), 71 deletions(-)

M board.ha
M main.ha
M notes.txt
M update.ha

@@ 1,5 1,4 @@
 use sdl2;
-use fmt; // XXX: TEMP
 
 def BOARD_WIDTH: int = 10;
 def BOARD_HEIGHT: int = 20;


@@ 33,6 32,8 @@ type board = struct {
 	active_i: int,
 	active_x: int,
 	active_y: int,
+	ghost_x: int,
+	ghost_y: int,
 	offs_x: int,
 	offs_y: int,
 };


@@ 55,25 56,38 @@ fn draw_board(state: *state, board: *board) (void | sdl2::error) = {
 			h = tex.height * BOARD_SCALE,
 		})?;
 	};
+
 	switch (state.state) {
 	case gamestate::CLEAR =>
 		return;
 	case => void;
 	};
 
-	const active = (board.active_x, board.active_y);
+	draw_active(state, board.ghost_x, board.ghost_y, 128)?;
+	draw_active(state, board.active_x, board.active_y, 255)?;
+};
+
+fn draw_active(
+	state: *state,
+	x: int, y: int,
+	alpha: u8,
+) (void | sdl2::error) = {
+	const active = (x, y);
+	const board = &state.board, tex = &state.piece;
+	const offs = (board.offs_x * SCENE_SCALE, board.offs_y * SCENE_SCALE);
 	for (let y = 0; y < TETROMINO_HEIGHT; y += 1)
 	for (let x = 0; x < TETROMINO_WIDTH; x += 1) {
 		let cell = board.active[board.active_i][y * TETROMINO_WIDTH + x];
 		if (cell == color::EMPTY) {
 			continue;
 		};
-		const x = x + board.active_x, y = y + board.active_y;
+		const x = x + active.0, y = y + active.1;
 		if (y < 0) {
 			continue;
 		};
 		let color = &color_map[cell];
 		sdl2::set_texture_color_mod(tex.tex, color.0, color.1, color.2)?;
+		sdl2::set_texture_alpha_mod(tex.tex, alpha)?;
 		sdl2::render_copy(state.render, tex.tex, null, &sdl2::rect {
 			x = offs.0 + x * BOARD_SCALE * tex.width,
 			y = offs.1 + y * BOARD_SCALE * tex.height,


@@ 83,6 97,49 @@ fn draw_board(state: *state, board: *board) (void | sdl2::error) = {
 	};
 };
 
+fn canmove(
+	state: *state,
+	active: *[TETROMINO_LEN]color,
+	dx: int, dy: int,
+) bool = {
+	const board = &state.board.cells;
+	const active_x = state.board.active_x;
+	const active_y = state.board.active_y;
+	for (let y = 0; y < TETROMINO_HEIGHT; y += 1)
+	for (let x = 0; x < TETROMINO_WIDTH; x += 1) {
+		const active_ix = y * TETROMINO_WIDTH + x;
+		if (active[active_ix] == 0) {
+			continue;
+		};
+		if (x + active_x < 0 || x + active_x >= BOARD_WIDTH) {
+			return false;
+		};
+		if (y + dy + active_y < 0) {
+			continue;
+		};
+		const x = x + dx, y = y + dy;
+		const board_ix = (y + active_y) * BOARD_WIDTH + (x + active_x);
+		if (board_ix: size >= len(board) || board[board_ix] != 0) {
+			return false;
+		};
+	};
+	return true;
+};
+
+fn update_ghost(state: *state) void = {
+	const board = &state.board;
+	const cells = &board.cells;
+	const active = &board.active[board.active_i];
+	let width = 0, height = 0;
+	activesize(state, &width, &height);
+
+	let y = 1;
+	for (canmove(state, active, 0, y); y += 1) void;
+
+	board.ghost_x = board.active_x;
+	board.ghost_y = board.active_y + y - 1;
+};
+
 fn commit(state: *state) void = {
 	let board = &state.board.cells;
 	let active = &state.board.active[state.board.active_i];


@@ 136,3 193,40 @@ fn shiftrow(state: *state, row: int) void = {
 		};
 	};
 };
+
+fn activesize(
+	state: *state,
+	width: nullable *int,
+	height: nullable *int,
+) void = {
+	let max_x = 0, max_y = 0;
+	const active = &state.board.active[state.board.active_i];
+	for (let y = 0; y < TETROMINO_HEIGHT; y += 1)
+	for (let x = 0; x < TETROMINO_WIDTH; x += 1) {
+		const active = active[y * TETROMINO_WIDTH + x] != 0;
+		if (active && x > max_x) {
+			max_x = x;
+		};
+		if (active && y > max_y) {
+			max_y = y;
+		};
+	};
+	match (width) {
+	case let ptr: *int =>
+		*ptr = max_x + 1;
+	case null => void;
+	};
+	match (height) {
+	case let ptr: *int =>
+		*ptr = max_y + 1;
+	case null => void;
+	};
+};
+
+fn clear_lines(state: *state) void = {
+	for (let i = 0z; i < len(state.clearlines); i += 1)
+	for (let x = 0; x < BOARD_WIDTH; x += 1) {
+		const y = state.clearlines[i];
+		state.board.cells[y * BOARD_WIDTH + x] = 0;
+	};
+};

@@ 57,7 57,8 @@ fn run() (void | sdl2::error) = {
 		640, 480, window_flags::NONE)?;
 	defer sdl2::destroy_window(win);
 
-	const render = sdl2::create_renderer(win, -1, renderer_flags::NONE)?;
+	const render = sdl2::create_renderer(win, -1,
+		renderer_flags::ACCELERATED)?;
 	defer sdl2::destroy_renderer(render);
 
 	const seed = time::now(time::clock::MONOTONIC).sec: u64;


@@ 79,6 80,9 @@ fn run() (void | sdl2::error) = {
 	};
 	defer sdl2::destroy_texture(state.piece.tex);
 	defer sdl2::destroy_texture(state.scene.tex);
+	defer sdl2::destroy_texture(state.clear.tex);
+
+	sdl2::set_texture_blend_mode(state.piece.tex, sdl2::blend_mode::BLEND)?;
 
 	let controller: nullable *sdl2::gamecontroller = null;
 	for (let i = 0; i < sdl2::numjoysticks()?; i += 1) {

@@ 1,4 1,3 @@
-- ghost blocks
 - instant place
 - fix thumbsticks
 - scorekeeping/display

@@ 97,6 97,7 @@ fn do_spawn(state: *state, now: u32) void = {
 	state.board.active_y = -height;
 	state.board.active_x = BOARD_WIDTH / 2 - width / 2;
 	state.state = gamestate::FALL;
+	update_ghost(state);
 	schedule_tick(state, now);
 };
 


@@ 138,6 139,7 @@ fn schedule_tick(state: *state, now: u32) void = {
 fn move_left(state: *state) void = {
 	if (state.board.active_x > 0) {
 		state.board.active_x -= 1;
+		update_ghost(state);
 	};
 };
 


@@ 146,6 148,7 @@ fn move_right(state: *state) void = {
 	activesize(state, &width, null);
 	if (state.board.active_x < BOARD_WIDTH - width) {
 		state.board.active_x += 1;
+		update_ghost(state);
 	};
 };
 


@@ 159,70 162,5 @@ fn rotate(state: *state) void = {
 		return;
 	};
 	board.active_i = next;
-};
-
-fn activesize(
-	state: *state,
-	width: nullable *int,
-	height: nullable *int,
-) void = {
-	let max_x = 0, max_y = 0;
-	const active = &state.board.active[state.board.active_i];
-	for (let y = 0; y < TETROMINO_HEIGHT; y += 1)
-	for (let x = 0; x < TETROMINO_WIDTH; x += 1) {
-		const active = active[y * TETROMINO_WIDTH + x] != 0;
-		if (active && x > max_x) {
-			max_x = x;
-		};
-		if (active && y > max_y) {
-			max_y = y;
-		};
-	};
-	match (width) {
-	case let ptr: *int =>
-		*ptr = max_x + 1;
-	case null => void;
-	};
-	match (height) {
-	case let ptr: *int =>
-		*ptr = max_y + 1;
-	case null => void;
-	};
-};
-
-fn canmove(
-	state: *state,
-	active: *[TETROMINO_LEN]color,
-	dx: int, dy: int,
-) bool = {
-	let board = &state.board.cells;
-	const active_x = state.board.active_x;
-	const active_y = state.board.active_y;
-	for (let y = 0; y < TETROMINO_HEIGHT; y += 1)
-	for (let x = 0; x < TETROMINO_WIDTH; x += 1) {
-		const active_ix = y * TETROMINO_WIDTH + x;
-		if (active[active_ix] == 0) {
-			continue;
-		};
-		if (x + active_x < 0 || x + active_x >= BOARD_WIDTH) {
-			return false;
-		};
-		if (y + active_y < 0) {
-			continue;
-		};
-		const x = x + dx, y = y + dy;
-		const board_ix = (y + active_y) * BOARD_WIDTH + (x + active_x);
-		if (board_ix: size >= len(board) || board[board_ix] != 0) {
-			return false;
-		};
-	};
-	return true;
-};
-
-fn clear_lines(state: *state) void = {
-	for (let i = 0z; i < len(state.clearlines); i += 1)
-	for (let x = 0; x < BOARD_WIDTH; x += 1) {
-		const y = state.clearlines[i];
-		state.board.cells[y * BOARD_WIDTH + x] = 0;
-	};
+	update_ghost(state);
 };