所以我最近在Allegro遇到了一些问题。我不知道导致它的原因,但我会尽力详细解释下面的问题。
在我的主要功能中,我有类似的东西:
int main()
{
Game *game = new Game();
game->init(800, 600, 60); //width, height, framerate
PlayState *playState = new PlayState(); //extends abstract class GameState
game->setDefaultState(playState);
game->startGame();
gMemoryTracker.reportAllocations(cout);
system("pause");
return 0;
}
这样可以正常工作,并且在每帧结束时打印经过的时间显示每帧大约16.7ms。但是,由于我希望Game类最终充当一个成熟的GameState管理器(目前它只支持一个GameState),我希望Game类的init函数调用每个GameState自己的个人init函数。显然,这意味着在调用Game的初始化函数之前注册每个GameState,所以我将main函数更改为如下所示:
int main()
{
Game *game = new Game();
//this is where the call to init used to be
PlayState *playState = new PlayState();
game->setDefaultState(playState);
game->init(800, 600, 60); //now this is called after we create a GameState and set it as default
game->startGame();
gMemoryTracker.reportAllocations(cout);
system("pause");
return 0;
}
问题是现在每帧渲染大约需要1100ms,即使Game类报告帧速率仍设置为60fps。为了尝试调试此问题,我对main进行了最后一次更改:
int main()
{
Game *game = new Game();
PlayState *playState = new PlayState();
game->init(800, 600, 60); //now init is being called after we create a new GameState, but before we set it as default
game->setDefaultState(playState);
game->startGame();
gMemoryTracker.reportAllocations(cout);
system("pause");
return 0;
}
但是这导致了与以前相同的问题,每帧渲染大约需要1100ms。看来这个问题只发生在我创建一个新的GameState后调用init时,所以我查看了PlayState类的构造函数和Game类的init函数,看看我是否能找到会导致这种行为的东西,但是我仍然无法找到原因。您可以在下面找到上述两个功能:
bool Game::init(int width, int height, float frameRate)
{
mFrameRate = frameRate;
bool result = mpGraphics->init(width, height); //initialize the graphics system
//this calls the init function for the default GameState. commented-out for debugging purposes
//result = result && mpDefaultState->init();
return result; //were all inits successful?
}
PlayState::PlayState() : GameState("play_state")
{
//create required graphics buffers and fonts
bgBuffer = new GraphicsBuffer(DISPLAY_SIZE.getX(), DISPLAY_SIZE.getY());
woodsBuffer = new GraphicsBuffer(ASSET_PATH + "Woods.png");
smurfBuffer = new GraphicsBuffer(ASSET_PATH + "smurf_sprites.png");
font = new Font(ASSET_PATH + "cour.ttf", 12);
smurfAnimation = new Animation(60, true); //create new animation for smurf walk cycle. args are animation framerate (must be <= game framerate) and loop animation
//load sprites from spritesheet
for (int y = 0; y < (int)SPRITE_SHEET_SIZE.getY() / (int)SPRITE_SIZE.getY(); y++)
{
for (int x = 0; x < (int)SPRITE_SHEET_SIZE.getX() / (int)SPRITE_SIZE.getX(); x++)
{
//there was already a class named Rectangle, so i had to get creative
UnequalSquare uSquare(x * (int)SPRITE_SIZE.getX(), y * (int)SPRITE_SIZE.getY(), (int)SPRITE_SIZE.getX(), (int)SPRITE_SIZE.getY());
smurfAnimation->addSprite(Sprite(*smurfBuffer, uSquare));
}
}
}
我还注意到的一件事是,如果我在PlayState的渲染功能中注释掉所有渲染调用,游戏将以适当的帧速率运行,但显然这不是一个可行的解决方案。我将在下面发布渲染功能。它目前效率不高(每帧都创建新的精灵对象),但这并不能解释为什么在创建PlayState实例之前调用Game.init()时它能完美运行。
void PlayState::render(GraphicsSystem* graphics, const Timer& frameTimer)
{
// Create background
Sprite bgSprite(*bgBuffer);
graphics->fill(*bgBuffer, Color(255, 0, 0));
// Create image
Sprite woodsSprite(*woodsBuffer);
Vector2D woodsLocation((DISPLAY_SIZE.getX() - (woodsSprite.getWidth() * WOODS_SCALE)) / 2.0, (DISPLAY_SIZE.getY() - (woodsSprite.getHeight() * WOODS_SCALE)) / 2.0);
// Draw Text
int fontWidth = font->getTextWidth(TEXT_STRING);
int fontHeight = font->getFontHeight();
for (int i = 0; i <= DISPLAY_SIZE.getY() / fontHeight; i++)
{
for (int j = 0; j <= DISPLAY_SIZE.getX() / fontWidth; j++)
{
graphics->drawText(*bgBuffer, Vector2D(j * fontWidth, i * fontHeight), TEXT_STRING, *font, Color());
}
}
//update the animation
smurfAnimation->update();
// Draw sprites to backbuffer
graphics->drawSpriteToBackbuffer(gZeroVector2D, bgSprite);
graphics->drawSpriteToBackbuffer(woodsLocation, woodsSprite, WOODS_SCALE);
graphics->drawSpriteToBackbuffer(gZeroVector2D, smurfAnimation->getCurrentSprite());
}
任何人都可以看到我可能遇到此问题的原因吗?我现在已经在这里工作了几个小时,我无法理解我的生活。
答案 0 :(得分:0)
我发现了问题。从Allegro 5文档:
除非您设置ALLEGRO_MEMORY_BITMAP标志,否则将为当前显示创建位图。向另一个显示器进行布局可能会很慢。
我在创建显示之前尝试创建位图,从而导致性能不佳。设置ALLEGRO_MEMORY_BITMAP标志可以显着提高帧速率,但每帧仍需要大约100ms-200ms。我认为这只是Allegro的一个弱点,从现在开始我需要考虑它。