diff --git a/source/main.cpp b/source/main.cpp
index 69fc0ebe7dbdda1ede5b9b062666c90680ed8b7a..fd9ab95c3ff3e581f4d5a7846d2e9f12b43ba920 100755
--- a/source/main.cpp
+++ b/source/main.cpp
@@ -39,7 +39,7 @@ MicroBit ubit;
/**
- * @brief An (X,Y) tuple type for storing 2D cartesian quantities
+ * @brief An (X,Y) tuple type for storing 2D Cartesian quantities
*/
struct Tuple {
int x;
@@ -123,7 +123,8 @@ enum class RotationDirection : uint8_t {
/*
* we store the sprites for our different block shapes in FLASH, i.e. read-only
- * storage. This requires manual data-packing as follows
+ * storage. This requires manual data-packing as follows.
+ * For most of them, we store four different orientations.
*/
const uint8_t FLAT_L_NORTH_SPRITE[] __attribute__ ((aligned (4))) = {
0xff, 0xff, // magic number requesting data to be stored in FLASH
@@ -358,43 +359,6 @@ MicroBitImage Block::image() const {
}
-void debug_test() {
- // XXX: simple debug test to check my FLASH images were stored correctly
- // for accurately-timed animations irrespective of framerate, track time
- unsigned long stopwatch = ubit.systemTime();
- unsigned long move_speed = 1000; // move down one block every 350ms
- // set up event handlers
- // ubit.messageBus.listen(
- // MICROBIT_ID_BUTTON_A, MICROBIT_BUTTON_EVT_CLICK, a_button_pressed
- // );
- // ubit.messageBus.listen(
- // MICROBIT_ID_BUTTON_B, MICROBIT_BUTTON_EVT_CLICK, b_button_pressed
- // );
- while (true) {
- // scroll random blocks down the screen
- Block block; // make a new random Block
- // starting positions:
- int x = 1;
- int y = -3;
- // print image until scrolled down off the screen
- while (y < 6) {
- ubit.display.clear();
- ubit.display.print(block.image(), x, y);
- {
- // check if enough time has elapsed to move the block
- unsigned long stopwatch_now = ubit.systemTime();
- if ((stopwatch_now - stopwatch) >= move_speed) {
- y++;
- // update the "stopwatch"
- stopwatch = stopwatch_now;
- }
- }
- ubit.sleep(50); // 50ms sleep for 20 FPS
- }
- }
-}
-
-
/**
* @brief Uses collision-detection to decide whether the given Block can move
* along the provided translation Vector.
@@ -424,7 +388,11 @@ bool can_shape_move(
destination.x < 0 or
destination.x > 4 or
destination.y > 4
- // NOTE: there is no check for negative Y since we allow it
+ /*
+ * NOTE: there is no check for negative Y since we allow
+ * shapes to poke out of the top of the screen as they
+ * descend into play.
+ */
) {
return false;
}
@@ -434,7 +402,7 @@ bool can_shape_move(
}
// check if the translated position of this pixel is not free
if (stacked.getPixelValue(destination.x, destination.y) != 0) {
- return false;
+ return false; // can't move because space is obstructed
}
}
}
@@ -476,7 +444,7 @@ bool can_shape_rotate(
}
// check if this pixel position is free in the stacked image
if (stacked.getPixelValue(destination.x, destination.y) != 0) {
- return false;
+ return false; // space is obstructed so can't rotate
}
}
}
@@ -485,9 +453,11 @@ bool can_shape_rotate(
return true;
}
+
+/* begin game state variables */
+
// this image contains all stacked shapes --it covers the entire screen
MicroBitImage stacked_shapes(5, 5);
-// game state variables
bool game_over;
// player left/right shift request tracker
int move_command = 0; // 0 = do nothing, -1 = shift left, +1 = shift right
@@ -496,6 +466,8 @@ int rotate_command = 0; // 0 = do nothing, -1 = rotate acw, +1 = rotate cw
// player's score
int score = 0;
+/* end game state variables */
+
/*
* our event handler functions take the name of the in-game command they
@@ -506,14 +478,17 @@ void move_left(MicroBitEvent) {
move_command = -1;
}
+
void move_right(MicroBitEvent) {
move_command = +1;
}
+
void rotate_acw(MicroBitEvent) {
rotate_command = -1;
}
+
void rotate_cw(MicroBitEvent) {
rotate_command = +1;
}
@@ -521,7 +496,7 @@ void rotate_cw(MicroBitEvent) {
/**
* @brief Returns true/false for whether the given row of the given image is
- * contiquous or not, that is, if it is full of non-clear pixels.
+ * contiguous or not, that is, if it is full of non-clear pixels.
*/
bool is_row_contiquous(MicroBitImage stacked_shapes, int row) {
for (int x = 0; x < 5; x++) {
@@ -534,9 +509,10 @@ bool is_row_contiquous(MicroBitImage stacked_shapes, int row) {
return true;
}
+
/**
* @brief Given a reference to a MicroBitImage of stacked shapes, remove any
- * contiquous rows of pixels, shifting contents above them down.
+ * contiguous rows of pixels, shifting contents above them down.
* @returns the number of rows that were eliminated
*/
int eliminate_rows(MicroBitImage& stacked_shapes) {
@@ -546,7 +522,7 @@ int eliminate_rows(MicroBitImage& stacked_shapes) {
do {
if (is_row_contiquous(stacked_shapes, row)) {
eliminated++;
- // optimisaton: if on the last row, just shift entire image down
+ // optimisation: if on the last row, just shift entire image down
if (row == 4) {
stacked_shapes.shiftDown(1);
} else {
@@ -557,12 +533,20 @@ int eliminate_rows(MicroBitImage& stacked_shapes) {
stacked_shapes.setPixelValue(x, above + 1, value);
}
}
+ // TODO: we don't clear the top row, but perhaps we should?
}
} else {
- // only go up the image when the current row is no longer contiguous
+ /*
+ * only go up the image when the current row is no longer contiguous
+ * --we do this because if we have just eliminated a row, we need
+ * to check that same row again because everything will have shifted
+ * down by one and the next row (the new row now in this place)
+ * might also be full and can be eliminated.
+ */
row--;
}
} while (row > 0);
+ // TODO: we don't check if the top row can be eliminated, perhaps we should?
// return the number of eliminated rows
return eliminated;
}
@@ -683,7 +667,6 @@ void start_new_game() {
score += (1 + eliminated_count * 5);
}
}
- // TODO: clean up game state
// remove event-handlers
ubit.messageBus.ignore(
MICROBIT_ID_BUTTON_A, MICROBIT_BUTTON_EVT_CLICK, rotate_acw