主要问题是，为什么常规for循环工作和增强的for循环不起作用。无效增强for循环的描述如下。
解决!!!我将把我的描述留给下面的问题，但我做了一些代码，并发现你不能通过增强的for循环移动sprite。你需要一个实际的for循环。看看我的updateSprites函数（我刚刚实现的）workingUpdateSprites函数。
（我之前遇到的问题可能会忽略它） SFML根本没有将我的精灵移动到右边。我有一个updateSprites函数，它将空闲帧向右移动（出于实验原因），由播放器更新函数调用，然后由引擎更新函数调用。通过将精灵返回到主引擎并简单地绘制精灵来显示精灵。
Player.cpp
<i>
#include "Player.h"
#include "Engine.h"
#include <math.h>
#include <windows.h>
#include <string>
#define _MYDEBUG1
void Player::updateSprites() { //Changes x and y variables for EVERY player sprite upon each iteration of the game loop
for (Sprite i : idle)
i.move(1, 0);
}
//idk why the for loop works and the enhanced one doesn't.
void Player::workingUpdateSprites() { //Changes x and y variables for EVERY player sprite upon each iteration of the game loop
for (int i = 0; i < ARRAYSIZE(idle); i++)
idle[i].move(1, 0);
}
void Player::update() { //God method that updates the player class {accessed by main engine}
updateVisuals();
}
void Player::updateVisuals() {
updateSprites();
}
Sprite Player::getPlayerSprite() { //return image of player sprite to get printed in the engine file
if (movement->getDirection() == 0) { //also determines which sprite to send and at what frame
int amtFrameTimePerSprite = frameIdleMaxCounterVal / ARRAYSIZE(idle); //gets amount of frame time per sprite
if (frameIdleMaxCounterVal - frameIdleCounter > amtFrameTimePerSprite) //divides frameIdleCount by amtFrameTimePerSprite to get exact index
return idle[(int)floor(frameIdleCounter / amtFrameTimePerSprite)];
else
return idle[ARRAYSIZE(idle) - 1];
}
return idle[0];
}
Player::Player(int x, int y) { //Constructs superclass(es) and sprites
frameIdleMaxCounterVal = 240;
///////-----------------------------------------------------CONSTRUCION OF ALL PLAYER SPRITES BEGINS----------------------------------------////////////////
//constructs idle sprites into array
for (int i = 0; i < ARRAYSIZE(tIdle); i++) {
if (i == 3) {
if (!tIdle[i].loadFromFile("resources\\player\\playerSass\\playerSass1.png")) {
throw "Could not load player idle frames";
}
}
else {
if (!tIdle[i].loadFromFile("resources\\player\\playerSass\\playerSass" + std::to_string(i) + ".png"))
throw "could not load player idle frames";
}
idle[i].setTexture(tIdle[i]);
idle[i].setPosition(x, y);
}
//constructs movement up sprites into array
for (int i = 0; i < ARRAYSIZE(tMvtUp); i++) {
if (!tMvtUp[i].loadFromFile("resources\\player\\playerSass\\mvtUp\\playerMvtUp" + std::to_string(++i) + ".png"))
throw "could not load player movement up frames";
mvtUp[i].setTexture(tMvtUp[i]);
mvtUp[i].setPosition(x, y);
}
//constructs movement down sprites into array
for (int i = 0; i < ARRAYSIZE(tMvtDown); i++) {
if (!tMvtDown[i].loadFromFile("resources\\player\\playerSass\\mvtDown\\playerMvtDown" + std::to_string(++i) + ".png"))
throw "could not load player movement down frames";
mvtDown[i].setTexture(tMvtDown[i]);
mvtDown[i].setPosition(x, y);
}
//constructs movement left sprites into array
for (int i = 0; i < ARRAYSIZE(tMvtLeft); i++) {
if (!tMvtLeft[i].loadFromFile("resources\\player\\playerSass\\mvtLeft\\playerMvtLeft" + std::to_string(++i) + ".png"))
throw "could not load player movement left frames";
mvtLeft[i].setTexture(tMvtLeft[i]);
mvtLeft[i].setPosition(x, y);
}
//constructs movement down sprites into array
for (int i = 0; i < ARRAYSIZE(tMvtRight); i++) {
if (!tMvtRight[i].loadFromFile("resources\\player\\playerSass\\mvtRight\\playerMvtRight" + std::to_string(++i) + ".png"))
throw "could not load player movement right frames";
mvtRight[i].setTexture(tMvtRight[i]);
mvtRight[i].setPosition(x, y);
}
///////------------------------------------CONSTRUCTION OF ALL PLAYER ANIMATION FRAMES END---------------------------------------------------//////////
//////-------------------------------------CONSTRUCIION OF MOVEMENT-----------------------------------------------
movement = new Movement(x, y);
}
</i>
Player.h
的
的#include <SFML\Graphics.hpp>
#include "Movement.h"
#ifndef _PLAYER_H
#define _PLAYER_H
using namespace sf;
class Player {
private:
Movement *movement;
Sprite idle[4], mvtUp[8], mvtDown[8], mvtLeft[8], mvtRight[8];
Texture tIdle[4], tMvtUp[8], tMvtDown[8], tMvtLeft[8], tMvtRight[8];
int frameIdleCounter = 1, frameIdleMaxCounterVal = 20;
void updateVisuals();
void updateCounters();
void updateSprites();
public:
Sprite getPlayerSprite();
int getX();
int getY();
void update();
Player(int x, int y);
};
#endif
的
Engine.cpp
的
的#include "Engine.h"
#include <SFML\Graphics.hpp>
#include <iostream>
#define _PAUSEDISPLAYl
#define _MYDEBUGf
bool Engine::init() {
#ifdef _MYDEBUG
freopen("conin$", "r", stdin);
freopen("conout$", "w", stdout);
freopen("conout$", "w", stderr);
#endif
window = new sf::RenderWindow(sf::VideoMode(800, 600, 32), "RPG", sf::Style::Close | sf::Style::Resize);
window->setFramerateLimit(60);
player = new Player(50, 50);
if (!window)
return false;
return true;
}
void Engine::mainLoop() {
//Loop until window is closed
while (window->isOpen()) {
processInput();
update();
window->clear(sf::Color::Black);
renderFrame();
window->display();
#ifdef _PAUSEDISPLAY
system("pause");
#endif
}
}
void Engine::processInput() {
sf::Event evt;
//loops through all window events
while (window->pollEvent(evt)) {
//window events
switch (evt.type) {
case sf::Event::Closed:
window->close();
case sf::Event::Resized:
std::cout << "width " << evt.size.width << " height " << evt.size.height;
break;
}
}
}
void Engine::update() { //the actual god method
player->update();
}
void Engine::renderFrame() { //calls object sprites to then be printed/displayed on the screen
window->draw(player->getPlayerSprite());
}
void Engine::go() {
if (!init())
throw "Initialization of Engine has Failed";
mainLoop();
}
Engine::Engine() {
}
Engine::~Engine() {
}
的
Engine.h
的
的#ifndef _ENGINE_H
#define _ENGINE_H
#include <SFML\Graphics.hpp>
#include "Player.h"
#include "Input.h"
class Engine {
private:
sf::RenderWindow* window;
Player *player;
bool init();
void mainLoop();
void processInput();
void update();
void renderFrame();
public:
Engine();
~Engine();
void go();
Input input[4];
};
#endif
的
答案 0 :(得分：1)
你绝对可以使用基于范围的for sprite，你只是错误地使用它们，通过修改循环中的临时副本而不是原始精灵。请尝试使用引用：
for (Sprite& i : idle)
i.move(1, 0);