Haskell 如何通过sdl2创建逐渐褪色的图像?
系统:安装sdl2的MacOS、ghc 如标题所述,如何通过sdl2创建逐渐褪色的图像?(请注意,该图由电脑中某个位置的.bmp文件提供。) 我已经写了下面的代码Haskell 如何通过sdl2创建逐渐褪色的图像?,haskell,sdl,sdl-2,Haskell,Sdl,Sdl 2,系统:安装sdl2的MacOS、ghc 如标题所述,如何通过sdl2创建逐渐褪色的图像?(请注意,该图由电脑中某个位置的.bmp文件提供。) 我已经写了下面的代码myflade实际上就是我需要的功能。但是,目前haskell会抱怨没有setSurfaceAlphamod {-# LANGUAGE OverloadedStrings #-} module Main (main) where import Control.Concurrent (threadDelay) import Foreig
myflade
实际上就是我需要的功能。但是,目前haskell会抱怨没有setSurfaceAlphamod
{-# LANGUAGE OverloadedStrings #-}
module Main (main) where
import Control.Concurrent (threadDelay)
import Foreign.C.Types
import SDL.Vect
import SDL.Raw.Video
import qualified SDL
screenWidth, screenHeight :: CInt
(screenWidth, screenHeight) = (960, 720)
fadedtime, fadednum :: Int
(fadedtime, fadednum) = (2000000, 10)
getDataFileName :: FilePath -> IO FilePath
getDataFileName = return
myFaded :: Int -> Int -> SDL.Surface -> SDL.Surface -> SDL.Window -> IO ()
myFaded fadedtime fadednum surface screenSurface window
| fadednum <= 0 = return ()
| otherwise = do
SDL.surfaceBlit surface Nothing screenSurface Nothing
SDL.updateWindowSurface window
threadDelay holdtime
newsurface <- SDL.setSurfaceAlphaMod surface alpha
myFaded (fadedtime - holdtime) (fadednum - 1) newsurface screenSurface window
where alpha = 2
holdtime = round $ fromIntegral $ fadedtime `div` fadednum
main :: IO ()
main = do
SDL.initialize [SDL.InitVideo]
window <- SDL.createWindow "our super mario" SDL.defaultWindow { SDL.windowInitialSize = V2 screenWidth screenHeight }
SDL.showWindow window
screenSurface <- SDL.getWindowSurface window
helloWorld <- getDataFileName "figs/Entry.bmp" >>= SDL.loadBMP
--SDL.surfaceBlit helloWorld Nothing screenSurface Nothing
--SDL.updateWindowSurface window
myFaded fadedtime fadednum helloWorld screenSurface window
--SDL.updateWindowSurface window
--threadDelay 2000000
SDL.destroyWindow window
SDL.freeSurface helloWorld
SDL.quit
{-#语言重载字符串}
主模块(Main),其中
导入控制。并发(线程延迟)
导入外国C.C.类型
导入SDL.Vect
导入SDL.Raw.Video
进口合格SDL
屏幕宽度,屏幕高度::CInt
(屏幕宽度、屏幕高度)=(960720)
fadedtime,fadednum::Int
(fadedtime,fadednum)=(2000000,10)
getDataFileName::FilePath->IO文件路径
getDataFileName=return
myflade::Int->Int->SDL.Surface->SDL.Surface->SDL.Window->IO()
MyFaddedTime FaddedNum曲面屏幕曲面窗口
|fadednum我建议使用渲染器
和纹理
s而不是曲面
()。使用纹理
,可以通过以下方式设置alpha模式:
textureBlendMode texture $= BlendAlphaBlend
textureAlphaMod texture $= 255 - fadednum
请注意,这些是全局变量,因此您可能希望在copy
之后将textureAlphaMod
设置回255
您编写的代码的简化版本转换为使用渲染器
和纹理
将如下所示:
{-# LANGUAGE OverloadedStrings #-}
module Main (main) where
import Control.Concurrent (threadDelay)
import Foreign.C.Types
import Data.Word
import SDL.Vect
import qualified SDL
screenWidth, screenHeight :: CInt
(screenWidth, screenHeight) = (960, 720)
fadednum :: Word8
fadednum = 0
getDataFileName :: FilePath -> IO FilePath
getDataFileName = return
main :: IO ()
main = do
SDL.initialize [SDL.InitVideo]
window <- SDL.createWindow "our super mario" SDL.defaultWindow { SDL.windowInitialSize = V2 screenWidth screenHeight }
SDL.showWindow window
renderer <- SDL.createRenderer window (-1) SDL.defaultRenderer
bmp <- getDataFileName "Entry.bmp" >>= SDL.loadBMP
helloWorld <- SDL.createTextureFromSurface renderer bmp
SDL.freeSurface bmp
myFaded fadednum helloWorld renderer window
SDL.destroyWindow window
SDL.destroyTexture helloWorld
SDL.quit
myFaded :: Word8 -> SDL.Texture -> SDL.Renderer -> SDL.Window -> IO ()
myFaded fadednum texture renderer window
| fadednum == 255 = return ()
| otherwise = do
SDL.clear renderer
SDL.textureBlendMode texture SDL.$= SDL.BlendAlphaBlend
SDL.textureAlphaMod texture SDL.$= 255 - fadednum
SDL.copy renderer texture Nothing Nothing
SDL.textureAlphaMod texture SDL.$= 255
SDL.present renderer
threadDelay 10000
myFaded (fadednum + 1) texture renderer window
{-#语言重载字符串}
主模块(Main),其中
导入控制。并发(线程延迟)
导入外国C.C.类型
导入数据.Word
导入SDL.Vect
进口合格SDL
屏幕宽度,屏幕高度::CInt
(屏幕宽度、屏幕高度)=(960720)
fadednum::Word8
fadednum=0
getDataFileName::FilePath->IO文件路径
getDataFileName=return
main::IO()
main=do
SDL.initialize[SDL.InitVideo]
窗口SDL.Renderer->SDL.window->IO()
MyFadedNum纹理渲染器窗口
|fadednum==255=返回()
|否则=做
清除渲染器
SDL.textureBlendMode纹理SDL.$=SDL.BlendAlphaBlend
SDL.textureAlphaMod纹理SDL.$=255-fadednum
SDL.copy渲染器纹理无任何内容
SDL.textureAlphaMod纹理SDL.$=255
当前渲染器
线程延迟10000
MyFadded(fadednum+1)纹理渲染器窗口