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puzzles/pegs.c
Simon Tatham c0da615a93 Centralise initial clearing of the puzzle window. 
I don't know how I've never thought of this before! Pretty much every
game in this collection has to have a mechanism for noticing when
game_redraw is called for the first time on a new drawstate, and if
so, start by covering the whole window with a filled rectangle of the
background colour. This is a pain for implementers, and also awkward
because the drawstate often has to _work out_ its own pixel size (or
else remember it from when its size method was called).

The backends all do that so that the frontends don't have to guarantee
anything about the initial window contents. But that's a silly
tradeoff to begin with (there are way more backends than frontends, so
this _adds_ work rather than saving it), and also, in this code base
there's a standard way to handle things you don't want to have to do
in every backend _or_ every frontend: do them just once in the midend!

So now that rectangle-drawing operation happens in midend_redraw, and
I've been able to remove it from almost every puzzle. (A couple of
puzzles have other approaches: Slant didn't have a rectangle-draw
because it handles even the game borders using its per-tile redraw
function, and Untangle clears the whole window on every redraw
_anyway_ because it would just be too confusing not to.)

In some cases I've also been able to remove the 'started' flag from
the drawstate. But in many cases that has to stay because it also
triggers drawing of static display furniture other than the
background.
2021-04-25 13:07:59 +01:00

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/*
* pegs.c: the classic Peg Solitaire game.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <ctype.h>
#include <math.h>
#include "puzzles.h"
#include "tree234.h"
#define GRID_HOLE 0
#define GRID_PEG 1
#define GRID_OBST 2
#define GRID_CURSOR 10
#define GRID_JUMPING 20
enum {
COL_BACKGROUND,
COL_HIGHLIGHT,
COL_LOWLIGHT,
COL_PEG,
COL_CURSOR,
NCOLOURS
};
/*
* Grid shapes. I do some macro ickery here to ensure that my enum
* and the various forms of my name list always match up.
*/
#define TYPELIST(A) \
A(CROSS,Cross,cross) \
A(OCTAGON,Octagon,octagon) \
A(RANDOM,Random,random)
#define ENUM(upper,title,lower) TYPE_ ## upper,
#define TITLE(upper,title,lower) #title,
#define LOWER(upper,title,lower) #lower,
#define CONFIG(upper,title,lower) ":" #title
enum { TYPELIST(ENUM) TYPECOUNT };
static char const *const pegs_titletypes[] = { TYPELIST(TITLE) };
static char const *const pegs_lowertypes[] = { TYPELIST(LOWER) };
#define TYPECONFIG TYPELIST(CONFIG)
#define FLASH_FRAME 0.13F
struct game_params {
int w, h;
int type;
};
struct game_state {
int w, h;
bool completed;
unsigned char *grid;
};
static game_params *default_params(void)
{
game_params *ret = snew(game_params);
ret->w = ret->h = 7;
ret->type = TYPE_CROSS;
return ret;
}
static const struct game_params pegs_presets[] = {
{7, 7, TYPE_CROSS},
{7, 7, TYPE_OCTAGON},
{5, 5, TYPE_RANDOM},
{7, 7, TYPE_RANDOM},
{9, 9, TYPE_RANDOM},
};
static bool game_fetch_preset(int i, char **name, game_params **params)
{
game_params *ret;
char str[80];
if (i < 0 || i >= lenof(pegs_presets))
return false;
ret = snew(game_params);
*ret = pegs_presets[i];
strcpy(str, pegs_titletypes[ret->type]);
if (ret->type == TYPE_RANDOM)
sprintf(str + strlen(str), " %dx%d", ret->w, ret->h);
*name = dupstr(str);
*params = ret;
return true;
}
static void free_params(game_params *params)
{
sfree(params);
}
static game_params *dup_params(const game_params *params)
{
game_params *ret = snew(game_params);
*ret = *params; /* structure copy */
return ret;
}
static void decode_params(game_params *params, char const *string)
{
char const *p = string;
int i;
params->w = atoi(p);
while (*p && isdigit((unsigned char)*p)) p++;
if (*p == 'x') {
p++;
params->h = atoi(p);
while (*p && isdigit((unsigned char)*p)) p++;
} else {
params->h = params->w;
}
for (i = 0; i < lenof(pegs_lowertypes); i++)
if (!strcmp(p, pegs_lowertypes[i]))
params->type = i;
}
static char *encode_params(const game_params *params, bool full)
{
char str[80];
sprintf(str, "%dx%d", params->w, params->h);
if (full) {
assert(params->type >= 0 && params->type < lenof(pegs_lowertypes));
strcat(str, pegs_lowertypes[params->type]);
}
return dupstr(str);
}
static config_item *game_configure(const game_params *params)
{
config_item *ret = snewn(4, config_item);
char buf[80];
ret[0].name = "Width";
ret[0].type = C_STRING;
sprintf(buf, "%d", params->w);
ret[0].u.string.sval = dupstr(buf);
ret[1].name = "Height";
ret[1].type = C_STRING;
sprintf(buf, "%d", params->h);
ret[1].u.string.sval = dupstr(buf);
ret[2].name = "Board type";
ret[2].type = C_CHOICES;
ret[2].u.choices.choicenames = TYPECONFIG;
ret[2].u.choices.selected = params->type;
ret[3].name = NULL;
ret[3].type = C_END;
return ret;
}
static game_params *custom_params(const config_item *cfg)
{
game_params *ret = snew(game_params);
ret->w = atoi(cfg[0].u.string.sval);
ret->h = atoi(cfg[1].u.string.sval);
ret->type = cfg[2].u.choices.selected;
return ret;
}
static const char *validate_params(const game_params *params, bool full)
{
if (full && (params->w <= 3 || params->h <= 3))
return "Width and height must both be greater than three";
/*
* It might be possible to implement generalisations of Cross
* and Octagon, but only if I can find a proof that they're all
* soluble. For the moment, therefore, I'm going to disallow
* them at any size other than the standard one.
*/
if (full && (params->type == TYPE_CROSS || params->type == TYPE_OCTAGON)) {
if (params->w != 7 || params->h != 7)
return "This board type is only supported at 7x7";
}
return NULL;
}
/* ----------------------------------------------------------------------
* Beginning of code to generate random Peg Solitaire boards.
*
* This procedure is done with no aesthetic judgment, no effort at
* symmetry, no difficulty grading and generally no finesse
* whatsoever. We simply begin with an empty board containing a
* single peg, and repeatedly make random reverse moves until it's
* plausibly full. This typically yields a scrappy haphazard mess
* with several holes, an uneven shape, and no redeeming features
* except guaranteed solubility.
*
* My only concessions to sophistication are (a) to repeat the
* generation process until I at least get a grid that touches
* every edge of the specified board size, and (b) to try when
* selecting moves to reuse existing space rather than expanding
* into new space (so that non-rectangular board shape becomes a
* factor during play).
*/
struct move {
/*
* x,y are the start point of the move during generation (hence
* its endpoint during normal play).
*
* dx,dy are the direction of the move during generation.
* Absolute value 1. Hence, for example, x=3,y=5,dx=1,dy=0
* means that the move during generation starts at (3,5) and
* ends at (5,5), and vice versa during normal play.
*/
int x, y, dx, dy;
/*
* cost is 0, 1 or 2, depending on how many GRID_OBSTs we must
* turn into GRID_HOLEs to play this move.
*/
int cost;
};
static int movecmp(void *av, void *bv)
{
struct move *a = (struct move *)av;
struct move *b = (struct move *)bv;
if (a->y < b->y)
return -1;
else if (a->y > b->y)
return +1;
if (a->x < b->x)
return -1;
else if (a->x > b->x)
return +1;
if (a->dy < b->dy)
return -1;
else if (a->dy > b->dy)
return +1;
if (a->dx < b->dx)
return -1;
else if (a->dx > b->dx)
return +1;
return 0;
}
static int movecmpcost(void *av, void *bv)
{
struct move *a = (struct move *)av;
struct move *b = (struct move *)bv;
if (a->cost < b->cost)
return -1;
else if (a->cost > b->cost)
return +1;
return movecmp(av, bv);
}
struct movetrees {
tree234 *bymove, *bycost;
};
static void update_moves(unsigned char *grid, int w, int h, int x, int y,
struct movetrees *trees)
{
struct move move;
int dir, pos;
/*
* There are twelve moves that can include (x,y): three in each
* of four directions. Check each one to see if it's possible.
*/
for (dir = 0; dir < 4; dir++) {
int dx, dy;
if (dir & 1)
dx = 0, dy = dir - 2;
else
dy = 0, dx = dir - 1;
assert(abs(dx) + abs(dy) == 1);
for (pos = 0; pos < 3; pos++) {
int v1, v2, v3;
move.dx = dx;
move.dy = dy;
move.x = x - pos*dx;
move.y = y - pos*dy;
if (move.x < 0 || move.x >= w || move.y < 0 || move.y >= h)
continue; /* completely invalid move */
if (move.x+2*move.dx < 0 || move.x+2*move.dx >= w ||
move.y+2*move.dy < 0 || move.y+2*move.dy >= h)
continue; /* completely invalid move */
v1 = grid[move.y * w + move.x];
v2 = grid[(move.y+move.dy) * w + (move.x+move.dx)];
v3 = grid[(move.y+2*move.dy)*w + (move.x+2*move.dx)];
if (v1 == GRID_PEG && v2 != GRID_PEG && v3 != GRID_PEG) {
struct move *m;
move.cost = (v2 == GRID_OBST) + (v3 == GRID_OBST);
/*
* This move is possible. See if it's already in
* the tree.
*/
m = find234(trees->bymove, &move, NULL);
if (m && m->cost != move.cost) {
/*
* It's in the tree but listed with the wrong
* cost. Remove the old version.
*/
#ifdef GENERATION_DIAGNOSTICS
printf("correcting %d%+d,%d%+d at cost %d\n",
m->x, m->dx, m->y, m->dy, m->cost);
#endif
del234(trees->bymove, m);
del234(trees->bycost, m);
sfree(m);
m = NULL;
}
if (!m) {
struct move *m, *m2;
m = snew(struct move);
*m = move;
m2 = add234(trees->bymove, m);
m2 = add234(trees->bycost, m);
assert(m2 == m);
#ifdef GENERATION_DIAGNOSTICS
printf("adding %d%+d,%d%+d at cost %d\n",
move.x, move.dx, move.y, move.dy, move.cost);
#endif
} else {
#ifdef GENERATION_DIAGNOSTICS
printf("not adding %d%+d,%d%+d at cost %d\n",
move.x, move.dx, move.y, move.dy, move.cost);
#endif
}
} else {
/*
* This move is impossible. If it is already in the
* tree, delete it.
*
* (We make use here of the fact that del234
* doesn't have to be passed a pointer to the
* _actual_ element it's deleting: it merely needs
* one that compares equal to it, and it will
* return the one it deletes.)
*/
struct move *m = del234(trees->bymove, &move);
#ifdef GENERATION_DIAGNOSTICS
printf("%sdeleting %d%+d,%d%+d\n", m ? "" : "not ",
move.x, move.dx, move.y, move.dy);
#endif
if (m) {
del234(trees->bycost, m);
sfree(m);
}
}
}
}
}
static void pegs_genmoves(unsigned char *grid, int w, int h, random_state *rs)
{
struct movetrees atrees, *trees = &atrees;
struct move *m;
int x, y, i, nmoves;
trees->bymove = newtree234(movecmp);
trees->bycost = newtree234(movecmpcost);
for (y = 0; y < h; y++)
for (x = 0; x < w; x++)
if (grid[y*w+x] == GRID_PEG)
update_moves(grid, w, h, x, y, trees);
nmoves = 0;
while (1) {
int limit, maxcost, index;
struct move mtmp, move, *m;
/*
* See how many moves we can make at zero cost. Make one,
* if possible. Failing that, make a one-cost move, and
* then a two-cost one.
*
* After filling at least half the input grid, we no longer
* accept cost-2 moves: if that's our only option, we give
* up and finish.
*/
mtmp.y = h+1;
maxcost = (nmoves < w*h/2 ? 2 : 1);
m = NULL; /* placate optimiser */
for (mtmp.cost = 0; mtmp.cost <= maxcost; mtmp.cost++) {
limit = -1;
m = findrelpos234(trees->bycost, &mtmp, NULL, REL234_LT, &limit);
#ifdef GENERATION_DIAGNOSTICS
printf("%d moves available with cost %d\n", limit+1, mtmp.cost);
#endif
if (m)
break;
}
if (!m)
break;
index = random_upto(rs, limit+1);
move = *(struct move *)index234(trees->bycost, index);
#ifdef GENERATION_DIAGNOSTICS
printf("selecting move %d%+d,%d%+d at cost %d\n",
move.x, move.dx, move.y, move.dy, move.cost);
#endif
grid[move.y * w + move.x] = GRID_HOLE;
grid[(move.y+move.dy) * w + (move.x+move.dx)] = GRID_PEG;
grid[(move.y+2*move.dy)*w + (move.x+2*move.dx)] = GRID_PEG;
for (i = 0; i <= 2; i++) {
int tx = move.x + i*move.dx;
int ty = move.y + i*move.dy;
update_moves(grid, w, h, tx, ty, trees);
}
nmoves++;
}
while ((m = delpos234(trees->bymove, 0)) != NULL) {
del234(trees->bycost, m);
sfree(m);
}
freetree234(trees->bymove);
freetree234(trees->bycost);
}
static void pegs_generate(unsigned char *grid, int w, int h, random_state *rs)
{
while (1) {
int x, y, extremes;
memset(grid, GRID_OBST, w*h);
grid[(h/2) * w + (w/2)] = GRID_PEG;
#ifdef GENERATION_DIAGNOSTICS
printf("beginning move selection\n");
#endif
pegs_genmoves(grid, w, h, rs);
#ifdef GENERATION_DIAGNOSTICS
printf("finished move selection\n");
#endif
extremes = 0;
for (y = 0; y < h; y++) {
if (grid[y*w+0] != GRID_OBST)
extremes |= 1;
if (grid[y*w+w-1] != GRID_OBST)
extremes |= 2;
}
for (x = 0; x < w; x++) {
if (grid[0*w+x] != GRID_OBST)
extremes |= 4;
if (grid[(h-1)*w+x] != GRID_OBST)
extremes |= 8;
}
if (extremes == 15)
break;
#ifdef GENERATION_DIAGNOSTICS
printf("insufficient extent; trying again\n");
#endif
}
#ifdef GENERATION_DIAGNOSTICS
fflush(stdout);
#endif
}
/* ----------------------------------------------------------------------
* End of board generation code. Now for the client code which uses
* it as part of the puzzle.
*/
static char *new_game_desc(const game_params *params, random_state *rs,
char **aux, bool interactive)
{
int w = params->w, h = params->h;
unsigned char *grid;
char *ret;
int i;
grid = snewn(w*h, unsigned char);
if (params->type == TYPE_RANDOM) {
pegs_generate(grid, w, h, rs);
} else {
int x, y, cx, cy, v;
for (y = 0; y < h; y++)
for (x = 0; x < w; x++) {
v = GRID_OBST; /* placate optimiser */
switch (params->type) {
case TYPE_CROSS:
cx = abs(x - w/2);
cy = abs(y - h/2);
if (cx == 0 && cy == 0)
v = GRID_HOLE;
else if (cx > 1 && cy > 1)
v = GRID_OBST;
else
v = GRID_PEG;
break;
case TYPE_OCTAGON:
cx = abs(x - w/2);
cy = abs(y - h/2);
if (cx + cy > 1 + max(w,h)/2)
v = GRID_OBST;
else
v = GRID_PEG;
break;
}
grid[y*w+x] = v;
}
if (params->type == TYPE_OCTAGON) {
/*
* The octagonal (European) solitaire layout is
* actually _insoluble_ with the starting hole at the
* centre. Here's a proof:
*
* Colour the squares of the board diagonally in
* stripes of three different colours, which I'll call
* A, B and C. So the board looks like this:
*
* A B C
* A B C A B
* A B C A B C A
* B C A B C A B
* C A B C A B C
* B C A B C
* A B C
*
* Suppose we keep running track of the number of pegs
* occuping each colour of square. This colouring has
* the property that any valid move whatsoever changes
* all three of those counts by one (two of them go
* down and one goes up), which means that the _parity_
* of every count flips on every move.
*
* If the centre square starts off unoccupied, then
* there are twelve pegs on each colour and all three
* counts start off even; therefore, after 35 moves all
* three counts would have to be odd, which isn't
* possible if there's only one peg left. []
*
* This proof works just as well if the starting hole
* is _any_ of the thirteen positions labelled B. Also,
* we can stripe the board in the opposite direction
* and rule out any square labelled B in that colouring
* as well. This leaves:
*
* Y n Y
* n n Y n n
* Y n n Y n n Y
* n Y Y n Y Y n
* Y n n Y n n Y
* n n Y n n
* Y n Y
*
* where the ns are squares we've proved insoluble, and
* the Ys are the ones remaining.
*
* That doesn't prove all those starting positions to
* be soluble, of course; they're merely the ones we
* _haven't_ proved to be impossible. Nevertheless, it
* turns out that they are all soluble, so when the
* user requests an Octagon board the simplest thing is
* to pick one of these at random.
*
* Rather than picking equiprobably from those twelve
* positions, we'll pick equiprobably from the three
* equivalence classes
*/
switch (random_upto(rs, 3)) {
case 0:
/* Remove a random corner piece. */
{
int dx, dy;
dx = random_upto(rs, 2) * 2 - 1; /* +1 or -1 */
dy = random_upto(rs, 2) * 2 - 1; /* +1 or -1 */
if (random_upto(rs, 2))
dy *= 3;
else
dx *= 3;
grid[(3+dy)*w+(3+dx)] = GRID_HOLE;
}
break;
case 1:
/* Remove a random piece two from the centre. */
{
int dx, dy;
dx = 2 * (random_upto(rs, 2) * 2 - 1);
if (random_upto(rs, 2))
dy = 0;
else
dy = dx, dx = 0;
grid[(3+dy)*w+(3+dx)] = GRID_HOLE;
}
break;
default /* case 2 */:
/* Remove a random piece one from the centre. */
{
int dx, dy;
dx = random_upto(rs, 2) * 2 - 1;
if (random_upto(rs, 2))
dy = 0;
else
dy = dx, dx = 0;
grid[(3+dy)*w+(3+dx)] = GRID_HOLE;
}
break;
}
}
}
/*
* Encode a game description which is simply a long list of P
* for peg, H for hole or O for obstacle.
*/
ret = snewn(w*h+1, char);
for (i = 0; i < w*h; i++)
ret[i] = (grid[i] == GRID_PEG ? 'P' :
grid[i] == GRID_HOLE ? 'H' : 'O');
ret[w*h] = '\0';
sfree(grid);
return ret;
}
static const char *validate_desc(const game_params *params, const char *desc)
{
int len = params->w * params->h;
if (len != strlen(desc))
return "Game description is wrong length";
if (len != strspn(desc, "PHO"))
return "Invalid character in game description";
return NULL;
}
static game_state *new_game(midend *me, const game_params *params,
const char *desc)
{
int w = params->w, h = params->h;
game_state *state = snew(game_state);
int i;
state->w = w;
state->h = h;
state->completed = false;
state->grid = snewn(w*h, unsigned char);
for (i = 0; i < w*h; i++)
state->grid[i] = (desc[i] == 'P' ? GRID_PEG :
desc[i] == 'H' ? GRID_HOLE : GRID_OBST);
return state;
}
static game_state *dup_game(const game_state *state)
{
int w = state->w, h = state->h;
game_state *ret = snew(game_state);
ret->w = state->w;
ret->h = state->h;
ret->completed = state->completed;
ret->grid = snewn(w*h, unsigned char);
memcpy(ret->grid, state->grid, w*h);
return ret;
}
static void free_game(game_state *state)
{
sfree(state->grid);
sfree(state);
}
static char *solve_game(const game_state *state, const game_state *currstate,
const char *aux, const char **error)
{
return NULL;
}
static bool game_can_format_as_text_now(const game_params *params)
{
return true;
}
static char *game_text_format(const game_state *state)
{
int w = state->w, h = state->h;
int x, y;
char *ret;
ret = snewn((w+1)*h + 1, char);
for (y = 0; y < h; y++) {
for (x = 0; x < w; x++)
ret[y*(w+1)+x] = (state->grid[y*w+x] == GRID_HOLE ? '-' :
state->grid[y*w+x] == GRID_PEG ? '*' : ' ');
ret[y*(w+1)+w] = '\n';
}
ret[h*(w+1)] = '\0';
return ret;
}
struct game_ui {
bool dragging; /* is a drag in progress? */
int sx, sy; /* grid coords of drag start cell */
int dx, dy; /* pixel coords of current drag posn */
int cur_x, cur_y;
bool cur_visible, cur_jumping;
};
static game_ui *new_ui(const game_state *state)
{
game_ui *ui = snew(game_ui);
int x, y, v;
ui->sx = ui->sy = ui->dx = ui->dy = 0;
ui->dragging = false;
ui->cur_visible = false;
ui->cur_jumping = false;
/* make sure we start the cursor somewhere on the grid. */
for (x = 0; x < state->w; x++) {
for (y = 0; y < state->h; y++) {
v = state->grid[y*state->w+x];
if (v == GRID_PEG || v == GRID_HOLE) {
ui->cur_x = x; ui->cur_y = y;
goto found;
}
}
}
assert(!"new_ui found nowhere for cursor");
found:
return ui;
}
static void free_ui(game_ui *ui)
{
sfree(ui);
}
static char *encode_ui(const game_ui *ui)
{
return NULL;
}
static void decode_ui(game_ui *ui, const char *encoding)
{
}
static void game_changed_state(game_ui *ui, const game_state *oldstate,
const game_state *newstate)
{
/*
* Cancel a drag, in case the source square has become
* unoccupied.
*/
ui->dragging = false;
/*
* Also, cancel a keyboard-driven jump if one is half way to being
* input.
*/
ui->cur_jumping = false;
}
#define PREFERRED_TILE_SIZE 33
#define TILESIZE (ds->tilesize)
#define BORDER (TILESIZE / 2)
#define HIGHLIGHT_WIDTH (TILESIZE / 16)
#define COORD(x) ( BORDER + (x) * TILESIZE )
#define FROMCOORD(x) ( ((x) + TILESIZE - BORDER) / TILESIZE - 1 )
struct game_drawstate {
int tilesize;
blitter *drag_background;
bool dragging;
int dragx, dragy;
int w, h;
unsigned char *grid;
bool started;
int bgcolour;
};
static char *interpret_move(const game_state *state, game_ui *ui,
const game_drawstate *ds,
int x, int y, int button)
{
int w = state->w, h = state->h;
char buf[80];
if (button == LEFT_BUTTON) {
int tx, ty;
/*
* Left button down: we attempt to start a drag.
*/
/*
* There certainly shouldn't be a current drag in progress,
* unless the midend failed to send us button events in
* order; it has a responsibility to always get that right,
* so we can legitimately punish it by failing an
* assertion.
*/
assert(!ui->dragging);
tx = FROMCOORD(x);
ty = FROMCOORD(y);
if (tx >= 0 && tx < w && ty >= 0 && ty < h &&
state->grid[ty*w+tx] == GRID_PEG) {
ui->dragging = true;
ui->sx = tx;
ui->sy = ty;
ui->dx = x;
ui->dy = y;
ui->cur_visible = false;
ui->cur_jumping = false;
return UI_UPDATE;
}
} else if (button == LEFT_DRAG && ui->dragging) {
/*
* Mouse moved; just move the peg being dragged.
*/
ui->dx = x;
ui->dy = y;
return UI_UPDATE;
} else if (button == LEFT_RELEASE && ui->dragging) {
int tx, ty, dx, dy;
/*
* Button released. Identify the target square of the drag,
* see if it represents a valid move, and if so make it.
*/
ui->dragging = false; /* cancel the drag no matter what */
tx = FROMCOORD(x);
ty = FROMCOORD(y);
if (tx < 0 || tx >= w || ty < 0 || ty >= h)
return UI_UPDATE; /* target out of range */
dx = tx - ui->sx;
dy = ty - ui->sy;
if (max(abs(dx),abs(dy)) != 2 || min(abs(dx),abs(dy)) != 0)
return UI_UPDATE; /* move length was wrong */
dx /= 2;
dy /= 2;
if (state->grid[ty*w+tx] != GRID_HOLE ||
state->grid[(ty-dy)*w+(tx-dx)] != GRID_PEG ||
state->grid[ui->sy*w+ui->sx] != GRID_PEG)
return UI_UPDATE; /* grid contents were invalid */
/*
* We have a valid move. Encode it simply as source and
* destination coordinate pairs.
*/
sprintf(buf, "%d,%d-%d,%d", ui->sx, ui->sy, tx, ty);
return dupstr(buf);
} else if (IS_CURSOR_MOVE(button)) {
if (!ui->cur_jumping) {
/* Not jumping; move cursor as usual, making sure we don't
* leave the gameboard (which may be an irregular shape) */
int cx = ui->cur_x, cy = ui->cur_y;
move_cursor(button, &cx, &cy, w, h, false);
ui->cur_visible = true;
if (state->grid[cy*w+cx] == GRID_HOLE ||
state->grid[cy*w+cx] == GRID_PEG) {
ui->cur_x = cx;
ui->cur_y = cy;
}
return UI_UPDATE;
} else {
int dx, dy, mx, my, jx, jy;
/* We're jumping; if the requested direction has a hole, and
* there's a peg in the way, */
assert(state->grid[ui->cur_y*w+ui->cur_x] == GRID_PEG);
dx = (button == CURSOR_RIGHT) ? 1 : (button == CURSOR_LEFT) ? -1 : 0;
dy = (button == CURSOR_DOWN) ? 1 : (button == CURSOR_UP) ? -1 : 0;
mx = ui->cur_x+dx; my = ui->cur_y+dy;
jx = mx+dx; jy = my+dy;
ui->cur_jumping = false; /* reset, whatever. */
if (jx >= 0 && jy >= 0 && jx < w && jy < h &&
state->grid[my*w+mx] == GRID_PEG &&
state->grid[jy*w+jx] == GRID_HOLE) {
/* Move cursor to the jumped-to location (this felt more
* natural while playtesting) */
sprintf(buf, "%d,%d-%d,%d", ui->cur_x, ui->cur_y, jx, jy);
ui->cur_x = jx; ui->cur_y = jy;
return dupstr(buf);
}
return UI_UPDATE;
}
} else if (IS_CURSOR_SELECT(button)) {
if (!ui->cur_visible) {
ui->cur_visible = true;
return UI_UPDATE;
}
if (ui->cur_jumping) {
ui->cur_jumping = false;
return UI_UPDATE;
}
if (state->grid[ui->cur_y*w+ui->cur_x] == GRID_PEG) {
/* cursor is on peg: next arrow-move wil jump. */
ui->cur_jumping = true;
return UI_UPDATE;
}
return NULL;
}
return NULL;
}
static game_state *execute_move(const game_state *state, const char *move)
{
int w = state->w, h = state->h;
int sx, sy, tx, ty;
game_state *ret;
if (sscanf(move, "%d,%d-%d,%d", &sx, &sy, &tx, &ty) == 4) {
int mx, my, dx, dy;
if (sx < 0 || sx >= w || sy < 0 || sy >= h)
return NULL; /* source out of range */
if (tx < 0 || tx >= w || ty < 0 || ty >= h)
return NULL; /* target out of range */
dx = tx - sx;
dy = ty - sy;
if (max(abs(dx),abs(dy)) != 2 || min(abs(dx),abs(dy)) != 0)
return NULL; /* move length was wrong */
mx = sx + dx/2;
my = sy + dy/2;
if (state->grid[sy*w+sx] != GRID_PEG ||
state->grid[my*w+mx] != GRID_PEG ||
state->grid[ty*w+tx] != GRID_HOLE)
return NULL; /* grid contents were invalid */
ret = dup_game(state);
ret->grid[sy*w+sx] = GRID_HOLE;
ret->grid[my*w+mx] = GRID_HOLE;
ret->grid[ty*w+tx] = GRID_PEG;
/*
* Opinion varies on whether getting to a single peg counts as
* completing the game, or whether that peg has to be at a
* specific location (central in the classic cross game, for
* instance). For now we take the former, rather lax position.
*/
if (!ret->completed) {
int count = 0, i;
for (i = 0; i < w*h; i++)
if (ret->grid[i] == GRID_PEG)
count++;
if (count == 1)
ret->completed = true;
}
return ret;
}
return NULL;
}
/* ----------------------------------------------------------------------
* Drawing routines.
*/
static void game_compute_size(const game_params *params, int tilesize,
int *x, int *y)
{
/* Ick: fake up `ds->tilesize' for macro expansion purposes */
struct { int tilesize; } ads, *ds = &ads;
ads.tilesize = tilesize;
*x = TILESIZE * params->w + 2 * BORDER;
*y = TILESIZE * params->h + 2 * BORDER;
}
static void game_set_size(drawing *dr, game_drawstate *ds,
const game_params *params, int tilesize)
{
ds->tilesize = tilesize;
assert(TILESIZE > 0);
assert(!ds->drag_background); /* set_size is never called twice */
ds->drag_background = blitter_new(dr, TILESIZE, TILESIZE);
}
static float *game_colours(frontend *fe, int *ncolours)
{
float *ret = snewn(3 * NCOLOURS, float);
game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
ret[COL_PEG * 3 + 0] = 0.0F;
ret[COL_PEG * 3 + 1] = 0.0F;
ret[COL_PEG * 3 + 2] = 1.0F;
ret[COL_CURSOR * 3 + 0] = 0.5F;
ret[COL_CURSOR * 3 + 1] = 0.5F;
ret[COL_CURSOR * 3 + 2] = 1.0F;
*ncolours = NCOLOURS;
return ret;
}
static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
{
int w = state->w, h = state->h;
struct game_drawstate *ds = snew(struct game_drawstate);
ds->tilesize = 0; /* not decided yet */
/* We can't allocate the blitter rectangle for the drag background
* until we know what size to make it. */
ds->drag_background = NULL;
ds->dragging = false;
ds->w = w;
ds->h = h;
ds->grid = snewn(w*h, unsigned char);
memset(ds->grid, 255, w*h);
ds->started = false;
ds->bgcolour = -1;
return ds;
}
static void game_free_drawstate(drawing *dr, game_drawstate *ds)
{
if (ds->drag_background)
blitter_free(dr, ds->drag_background);
sfree(ds->grid);
sfree(ds);
}
static void draw_tile(drawing *dr, game_drawstate *ds,
int x, int y, int v, int bgcolour)
{
bool cursor = false, jumping = false;
int bg;
if (bgcolour >= 0) {
draw_rect(dr, x, y, TILESIZE, TILESIZE, bgcolour);
}
if (v >= GRID_JUMPING) {
jumping = true; v -= GRID_JUMPING;
}
if (v >= GRID_CURSOR) {
cursor = true; v -= GRID_CURSOR;
}
if (v == GRID_HOLE) {
bg = cursor ? COL_HIGHLIGHT : COL_LOWLIGHT;
assert(!jumping); /* can't jump from a hole! */
draw_circle(dr, x+TILESIZE/2, y+TILESIZE/2, TILESIZE/4,
bg, bg);
} else if (v == GRID_PEG) {
bg = (cursor || jumping) ? COL_CURSOR : COL_PEG;
draw_circle(dr, x+TILESIZE/2, y+TILESIZE/2, TILESIZE/3,
bg, bg);
bg = (!cursor || jumping) ? COL_PEG : COL_CURSOR;
draw_circle(dr, x+TILESIZE/2, y+TILESIZE/2, TILESIZE/4,
bg, bg);
}
draw_update(dr, x, y, TILESIZE, TILESIZE);
}
static void game_redraw(drawing *dr, game_drawstate *ds,
const game_state *oldstate, const game_state *state,
int dir, const game_ui *ui,
float animtime, float flashtime)
{
int w = state->w, h = state->h;
int x, y;
int bgcolour;
if (flashtime > 0) {
int frame = (int)(flashtime / FLASH_FRAME);
bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
} else
bgcolour = COL_BACKGROUND;
/*
* Erase the sprite currently being dragged, if any.
*/
if (ds->dragging) {
assert(ds->drag_background);
blitter_load(dr, ds->drag_background, ds->dragx, ds->dragy);
draw_update(dr, ds->dragx, ds->dragy, TILESIZE, TILESIZE);
ds->dragging = false;
}
if (!ds->started) {
/*
* Draw relief marks around all the squares that aren't
* GRID_OBST.
*/
for (y = 0; y < h; y++)
for (x = 0; x < w; x++)
if (state->grid[y*w+x] != GRID_OBST) {
/*
* First pass: draw the full relief square.
*/
int coords[6];
coords[0] = COORD(x+1) + HIGHLIGHT_WIDTH - 1;
coords[1] = COORD(y) - HIGHLIGHT_WIDTH;
coords[2] = COORD(x) - HIGHLIGHT_WIDTH;
coords[3] = COORD(y+1) + HIGHLIGHT_WIDTH - 1;
coords[4] = COORD(x) - HIGHLIGHT_WIDTH;
coords[5] = COORD(y) - HIGHLIGHT_WIDTH;
draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT);
coords[4] = COORD(x+1) + HIGHLIGHT_WIDTH - 1;
coords[5] = COORD(y+1) + HIGHLIGHT_WIDTH - 1;
draw_polygon(dr, coords, 3, COL_LOWLIGHT, COL_LOWLIGHT);
}
for (y = 0; y < h; y++)
for (x = 0; x < w; x++)
if (state->grid[y*w+x] != GRID_OBST) {
/*
* Second pass: draw everything but the two
* diagonal corners.
*/
draw_rect(dr, COORD(x) - HIGHLIGHT_WIDTH,
COORD(y) - HIGHLIGHT_WIDTH,
TILESIZE + HIGHLIGHT_WIDTH,
TILESIZE + HIGHLIGHT_WIDTH, COL_HIGHLIGHT);
draw_rect(dr, COORD(x),
COORD(y),
TILESIZE + HIGHLIGHT_WIDTH,
TILESIZE + HIGHLIGHT_WIDTH, COL_LOWLIGHT);
}
for (y = 0; y < h; y++)
for (x = 0; x < w; x++)
if (state->grid[y*w+x] != GRID_OBST) {
/*
* Third pass: draw a trapezium on each edge.
*/
int coords[8];
int dx, dy, s, sn, c;
for (dx = 0; dx < 2; dx++) {
dy = 1 - dx;
for (s = 0; s < 2; s++) {
sn = 2*s - 1;
c = s ? COL_LOWLIGHT : COL_HIGHLIGHT;
coords[0] = COORD(x) + (s*dx)*(TILESIZE-1);
coords[1] = COORD(y) + (s*dy)*(TILESIZE-1);
coords[2] = COORD(x) + (s*dx+dy)*(TILESIZE-1);
coords[3] = COORD(y) + (s*dy+dx)*(TILESIZE-1);
coords[4] = coords[2] - HIGHLIGHT_WIDTH * (dy-sn*dx);
coords[5] = coords[3] - HIGHLIGHT_WIDTH * (dx-sn*dy);
coords[6] = coords[0] + HIGHLIGHT_WIDTH * (dy+sn*dx);
coords[7] = coords[1] + HIGHLIGHT_WIDTH * (dx+sn*dy);
draw_polygon(dr, coords, 4, c, c);
}
}
}
for (y = 0; y < h; y++)
for (x = 0; x < w; x++)
if (state->grid[y*w+x] != GRID_OBST) {
/*
* Second pass: draw everything but the two
* diagonal corners.
*/
draw_rect(dr, COORD(x),
COORD(y),
TILESIZE,
TILESIZE, COL_BACKGROUND);
}
ds->started = true;
draw_update(dr, 0, 0,
TILESIZE * state->w + 2 * BORDER,
TILESIZE * state->h + 2 * BORDER);
}
/*
* Loop over the grid redrawing anything that looks as if it
* needs it.
*/
for (y = 0; y < h; y++)
for (x = 0; x < w; x++) {
int v;
v = state->grid[y*w+x];
/*
* Blank the source of a drag so it looks as if the
* user picked the peg up physically.
*/
if (ui->dragging && ui->sx == x && ui->sy == y && v == GRID_PEG)
v = GRID_HOLE;
if (ui->cur_visible && ui->cur_x == x && ui->cur_y == y)
v += ui->cur_jumping ? GRID_JUMPING : GRID_CURSOR;
if (v != GRID_OBST &&
(bgcolour != ds->bgcolour || /* always redraw when flashing */
v != ds->grid[y*w+x])) {
draw_tile(dr, ds, COORD(x), COORD(y), v, bgcolour);
ds->grid[y*w+x] = v;
}
}
/*
* Draw the dragging sprite if any.
*/
if (ui->dragging) {
ds->dragging = true;
ds->dragx = ui->dx - TILESIZE/2;
ds->dragy = ui->dy - TILESIZE/2;
blitter_save(dr, ds->drag_background, ds->dragx, ds->dragy);
draw_tile(dr, ds, ds->dragx, ds->dragy, GRID_PEG, -1);
}
ds->bgcolour = bgcolour;
}
static float game_anim_length(const game_state *oldstate,
const game_state *newstate, int dir, game_ui *ui)
{
return 0.0F;
}
static float game_flash_length(const game_state *oldstate,
const game_state *newstate, int dir, game_ui *ui)
{
if (!oldstate->completed && newstate->completed)
return 2 * FLASH_FRAME;
else
return 0.0F;
}
static void game_get_cursor_location(const game_ui *ui,
const game_drawstate *ds,
const game_state *state,
const game_params *params,
int *x, int *y, int *w, int *h)
{
if(ui->cur_visible) {
*x = COORD(ui->cur_x);
*y = COORD(ui->cur_y);
*w = *h = TILESIZE;
}
}
static int game_status(const game_state *state)
{
/*
* Dead-end situations are assumed to be rescuable by Undo, so we
* don't bother to identify them and return -1.
*/
return state->completed ? +1 : 0;
}
static bool game_timing_state(const game_state *state, game_ui *ui)
{
return true;
}
static void game_print_size(const game_params *params, float *x, float *y)
{
}
static void game_print(drawing *dr, const game_state *state, int tilesize)
{
}
#ifdef COMBINED
#define thegame pegs
#endif
const struct game thegame = {
"Pegs", "games.pegs", "pegs",
default_params,
game_fetch_preset, NULL,
decode_params,
encode_params,
free_params,
dup_params,
true, game_configure, custom_params,
validate_params,
new_game_desc,
validate_desc,
new_game,
dup_game,
free_game,
false, solve_game,
true, game_can_format_as_text_now, game_text_format,
new_ui,
free_ui,
encode_ui,
decode_ui,
NULL, /* game_request_keys */
game_changed_state,
interpret_move,
execute_move,
PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
game_colours,
game_new_drawstate,
game_free_drawstate,
game_redraw,
game_anim_length,
game_flash_length,
game_get_cursor_location,
game_status,
false, false, game_print_size, game_print,
false, /* wants_statusbar */
false, game_timing_state,
0, /* flags */
};
/* vim: set shiftwidth=4 tabstop=8: */
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