taisei/src/transition.c
Andrei Alexeyev 71109fd253
transition: more robust handling of "canceled" transitions
Ensure callbacks are always called, but if a transition was overwritten
by another set_transition() call mid-transition, pass a non-NULL
argument as the result. This allows the callback to gracefully cancel
whatever it was meant to do, if needed.
2023-04-07 16:08:50 +02:00

152 lines
3.2 KiB
C

/*
* This software is licensed under the terms of the MIT License.
* See COPYING for further information.
* ---
* Copyright (c) 2011-2019, Lukas Weber <laochailan@web.de>.
* Copyright (c) 2012-2019, Andrei Alexeyev <akari@taisei-project.org>.
*/
#include "taisei.h"
#include "transition.h"
#include "menu/ingamemenu.h"
#include "global.h"
Transition transition;
static CallChain swap_cc(CallChain *pcc, CallChain newcc) {
CallChain cc = *pcc;
*pcc = newcc;
return cc;
}
static CallChain pop_cc(CallChain *pcc) {
return swap_cc(pcc, NO_CALLCHAIN);
}
static void run_cc(CallChain *pcc, bool canceled) {
CallChain cc = pop_cc(pcc);
run_call_chain(&cc, (void*)(uintptr_t)canceled);
}
static void swap_cc_withcancel(CallChain *pcc, CallChain newcc) {
CallChain oldcc = swap_cc(pcc, newcc);
run_cc(&oldcc, true);
}
void TransFadeBlack(double fade) {
fade_out(fade);
}
void TransFadeWhite(double fade) {
colorfill(fade, fade, fade, fade);
}
void TransLoader(double fade) {
r_color4(fade, fade, fade, fade);
fill_screen("loading");
r_color4(1, 1, 1, 1);
}
void TransEmpty(double fade) { }
static bool popq(void) {
if(transition.queued.rule) {
transition.rule2 = transition.rule;
transition.rule = transition.queued.rule;
if(transition.state == TRANS_IDLE || transition.rule2 == transition.rule) {
transition.rule2 = NULL;
}
transition.dur1 = transition.queued.dur1;
transition.dur2 = transition.queued.dur2;
swap_cc_withcancel(&transition.cc, transition.queued.cc);
transition.queued.cc = NO_CALLCHAIN;
transition.queued.rule = NULL;
if(transition.dur1 <= 0) {
transition.fade = 1.0;
transition.state = TRANS_FADE_OUT;
} else {
transition.state = TRANS_FADE_IN;
}
return true;
}
return false;
}
static void setq(TransitionRule rule, int dur1, int dur2, CallChain cc) {
transition.queued.rule = rule;
transition.queued.dur1 = dur1;
transition.queued.dur2 = dur2;
swap_cc_withcancel(&transition.queued.cc, cc);
}
void set_transition(TransitionRule rule, int dur1, int dur2, CallChain cc) {
static bool initialized = false;
if(!rule) {
return;
}
setq(rule, dur1, dur2, cc);
if(!initialized) {
popq();
initialized = true;
transition.rule2 = NULL;
}
if(transition.state == TRANS_IDLE || rule == transition.rule) {
popq();
}
}
static bool check_transition(void) {
if(transition.state == TRANS_IDLE) {
return false;
}
if(!transition.rule) {
transition.state = TRANS_IDLE;
return false;
}
return true;
}
void draw_transition(void) {
if(!check_transition()) {
return;
}
transition.rule(transition.fade);
if(transition.rule2 && transition.rule2 != transition.rule) {
transition.rule2(transition.fade);
}
}
void update_transition(void) {
if(!check_transition()) {
return;
}
if(transition.state == TRANS_FADE_IN) {
transition.fade = approach(transition.fade, 1.0, 1.0/transition.dur1);
if(transition.fade == 1.0) {
transition.state = TRANS_FADE_OUT;
popq();
run_cc(&transition.cc, false);
}
} else if(transition.state == TRANS_FADE_OUT) {
transition.fade = transition.dur2 ? approach(transition.fade, 0.0, 1.0/transition.dur2) : 0.0;
if(transition.fade == 0.0) {
transition.state = TRANS_IDLE;
popq();
}
}
}