+
+#include <stdio.h>
+#include <assert.h>
+
+#include "puzzles.h"
+
+struct midend_data {
+ frontend *frontend;
+ char *seed;
+ int nstates, statesize, statepos;
+
+ game_params **presets;
+ char **preset_names;
+ int npresets, presetsize;
+
+ game_params *params;
+ game_state **states;
+ game_drawstate *drawstate;
+ game_state *oldstate;
+ float anim_time, anim_pos;
+ float flash_time, flash_pos;
+};
+
+#define ensure(me) do { \
+ if ((me)->nstates >= (me)->statesize) { \
+ (me)->statesize = (me)->nstates + 128; \
+ (me)->states = sresize((me)->states, (me)->statesize, game_state *); \
+ } \
+} while (0)
+
+midend_data *midend_new(frontend *frontend)
+{
+ midend_data *me = snew(midend_data);
+
+ me->frontend = frontend;
+ me->nstates = me->statesize = me->statepos = 0;
+ me->states = NULL;
+ me->params = default_params();
+ me->seed = NULL;
+ me->drawstate = NULL;
+ me->oldstate = NULL;
+ me->presets = NULL;
+ me->preset_names = NULL;
+ me->npresets = me->presetsize = 0;
+ me->anim_time = me->anim_pos = 0.0F;
+ me->flash_time = me->flash_pos = 0.0F;
+
+ return me;
+}
+
+void midend_free(midend_data *me)
+{
+ sfree(me->states);
+ sfree(me->seed);
+ free_params(me->params);
+ sfree(me);
+}
+
+void midend_size(midend_data *me, int *x, int *y)
+{
+ game_size(me->params, x, y);
+}
+
+void midend_set_params(midend_data *me, game_params *params)
+{
+ free_params(me->params);
+ me->params = dup_params(params);
+}
+
+void midend_new_game(midend_data *me, char *seed)
+{
+ while (me->nstates > 0)
+ free_game(me->states[--me->nstates]);
+
+ if (me->drawstate)
+ game_free_drawstate(me->drawstate);
+
+ assert(me->nstates == 0);
+
+ sfree(me->seed);
+ if (seed)
+ me->seed = dupstr(seed);
+ else
+ me->seed = new_game_seed(me->params);
+
+ ensure(me);
+ me->states[me->nstates++] = new_game(me->params, me->seed);
+ me->statepos = 1;
+ me->drawstate = game_new_drawstate(me->states[0]);
+}
+
+void midend_restart_game(midend_data *me)
+{
+ while (me->nstates > 1)
+ free_game(me->states[--me->nstates]);
+ me->statepos = me->nstates;
+}
+
+static int midend_undo(midend_data *me)
+{
+ if (me->statepos > 1) {
+ me->statepos--;
+ return 1;
+ } else
+ return 0;
+}
+
+static int midend_redo(midend_data *me)
+{
+ if (me->statepos < me->nstates) {
+ me->statepos++;
+ return 1;
+ } else
+ return 0;
+}
+
+static void midend_finish_move(midend_data *me)
+{
+ float flashtime;
+
+ if (me->oldstate || me->statepos > 1) {
+ flashtime = game_flash_length(me->oldstate ? me->oldstate :
+ me->states[me->statepos-2],
+ me->states[me->statepos-1]);
+ if (flashtime > 0) {
+ me->flash_pos = 0.0F;
+ me->flash_time = flashtime;
+ }
+ }
+
+ if (me->oldstate)
+ free_game(me->oldstate);
+ me->oldstate = NULL;
+ me->anim_pos = me->anim_time = 0;
+
+ if (me->flash_time == 0 && me->anim_time == 0)
+ deactivate_timer(me->frontend);
+ else
+ activate_timer(me->frontend);
+}
+
+int midend_process_key(midend_data *me, int x, int y, int button)
+{
+ game_state *oldstate = dup_game(me->states[me->statepos - 1]);
+ float anim_time;
+
+ if (me->oldstate || me->anim_time) {
+ midend_finish_move(me);
+ midend_redraw(me);
+ }
+
+ if (button == 'n' || button == 'N' || button == '\x0E') {
+ midend_new_game(me, NULL);
+ midend_redraw(me);
+ return 1; /* never animate */
+ } else if (button == 'r' || button == 'R') {
+ midend_restart_game(me);
+ midend_redraw(me);
+ return 1; /* never animate */
+ } else if (button == 'u' || button == 'u' ||
+ button == '\x1A' || button == '\x1F') {
+ if (!midend_undo(me))
+ return 1;
+ } else if (button == '\x12') {
+ if (!midend_redo(me))
+ return 1;
+ } else if (button == 'q' || button == 'Q' || button == '\x11') {
+ free_game(oldstate);
+ return 0;
+ } else {
+ game_state *s = make_move(me->states[me->statepos-1], x, y, button);
+
+ if (s) {
+ while (me->nstates > me->statepos)
+ free_game(me->states[--me->nstates]);
+ ensure(me);
+ me->states[me->nstates] = s;
+ me->statepos = ++me->nstates;
+ } else {
+ free_game(oldstate);
+ return 1;
+ }
+ }
+
+ /*
+ * See if this move requires an animation.
+ */
+ anim_time = game_anim_length(oldstate, me->states[me->statepos-1]);
+
+ me->oldstate = oldstate;
+ if (anim_time > 0) {
+ me->anim_time = anim_time;
+ } else {
+ me->anim_time = 0.0;
+ midend_finish_move(me);
+ }
+ me->anim_pos = 0.0;
+
+ midend_redraw(me);
+
+ activate_timer(me->frontend);
+
+ return 1;
+}
+
+void midend_redraw(midend_data *me)
+{
+ if (me->statepos > 0 && me->drawstate) {
+ start_draw(me->frontend);
+ if (me->oldstate && me->anim_time > 0 &&
+ me->anim_pos < me->anim_time) {
+ game_redraw(me->frontend, me->drawstate, me->oldstate,
+ me->states[me->statepos-1], me->anim_pos,
+ me->flash_pos);
+ } else {
+ game_redraw(me->frontend, me->drawstate, NULL,
+ me->states[me->statepos-1], 0.0, me->flash_pos);
+ }
+ end_draw(me->frontend);
+ }
+}
+
+void midend_timer(midend_data *me, float tplus)
+{
+ me->anim_pos += tplus;
+ if (me->anim_pos >= me->anim_time ||
+ me->anim_time == 0 || !me->oldstate) {
+ if (me->anim_time > 0)
+ midend_finish_move(me);
+ }
+ me->flash_pos += tplus;
+ if (me->flash_pos >= me->flash_time || me->flash_time == 0) {
+ me->flash_pos = me->flash_time = 0;
+ }
+ if (me->flash_time == 0 && me->anim_time == 0)
+ deactivate_timer(me->frontend);
+ midend_redraw(me);
+}
+
+float *midend_colours(midend_data *me, int *ncolours)
+{
+ game_state *state = NULL;
+ float *ret;
+
+ if (me->nstates == 0) {
+ char *seed = new_game_seed(me->params);
+ state = new_game(me->params, seed);
+ sfree(seed);
+ } else
+ state = me->states[0];
+
+ ret = game_colours(me->frontend, state, ncolours);
+
+ if (me->nstates == 0)
+ free_game(state);
+
+ return ret;
+}
+
+int midend_num_presets(midend_data *me)
+{
+ if (!me->npresets) {
+ char *name;
+ game_params *preset;
+
+ while (game_fetch_preset(me->npresets, &name, &preset)) {
+ if (me->presetsize <= me->npresets) {
+ me->presetsize = me->npresets + 10;
+ me->presets = sresize(me->presets, me->presetsize,
+ game_params *);
+ me->preset_names = sresize(me->preset_names, me->presetsize,
+ char *);
+ }
+
+ me->presets[me->npresets] = preset;
+ me->preset_names[me->npresets] = name;
+ me->npresets++;
+ }
+ }
+
+ return me->npresets;
+}
+
+void midend_fetch_preset(midend_data *me, int n,
+ char **name, game_params **params)
+{
+ assert(n >= 0 && n < me->npresets);
+ *name = me->preset_names[n];
+ *params = me->presets[n];
+}
+
+int midend_wants_statusbar(midend_data *me)
+{
+ return game_wants_statusbar();
+}