~alcinnz/Mondrian

ref: 94547420f10f0af679958e805b2abbf68d0e6ee2 Mondrian/lib/Graphics/Rendering/Rect/Image.hs -rw-r--r-- 2.7 KiB
94547420 — Adrian Cochrane Build texturing infrastructure & implement background-color! 1 year, 4 months ago 
                                                                                
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{-# LANGUAGE OverloadedStrings #-}
module Graphics.Rendering.Rect.Image(
    Atlas, buildAtlas, Texture(..), atlasLookup) where

import qualified Data.HashMap.Lazy as HM
import Data.Text (Text)
import Codec.Picture (DynamicImage(..), Image(..), PixelRGBA8(..), generateImage)
import Codec.Picture.Types (promoteImage, dynamicMap)

import Control.Monad.IO.Class (MonadIO(..))
import Control.Monad (forM)
import Data.Maybe (fromMaybe)

import Typograffiti.GL
import Graphics.GL.Core32
import Graphics.GL.Types
import Graphics.GL.Ext.EXT.Cmyka
import Graphics.GL.Ext.SGIX.Ycrcb
import Graphics.GL.Compatibility32

import Data.Vector.Storable (unsafeWith, unsafeCast, Vector)
import Foreign.Ptr (castPtr)
import Foreign.Marshal.Array (allocaArray, peekArray)

data Atlas = Atlas { unAtlas :: HM.HashMap Text GLuint }

buildAtlas :: MonadIO m => (Text -> IO DynamicImage) -> [Text] -> m Atlas
buildAtlas cb [] = return $ Atlas HM.empty
buildAtlas cb srcs = do
    -- TODO Merge textures into an actual atlas.
    let len = length srcs
    textures <- liftIO $ allocaArray (toEnum len) $ \ptr -> do
        glGenTextures (toEnum len) ptr
        peekArray len ptr
    imgs <- liftIO $ forM srcs cb

    forM (zip textures imgs) $ \(texture, dyn) -> do
        -- NOTE: `unsafe` crashes with a divide-by-zero given a `Vector ()`
        let img = dynamicMap (unsafeCast . imageData) dyn :: Vector Word
        let (format, word) = glFormat dyn
        liftIO $ glBindTexture GL_TEXTURE_2D texture
        liftIO $ unsafeWith img $ -- FIXME: Crashes
            glTexImage2D GL_TEXTURE_2D 0 GL_RGBA
                    (toEnum $ dynamicMap imageWidth dyn)
                    (toEnum $ dynamicMap imageHeight dyn)
                    0 format word . castPtr

    return $ Atlas $ HM.fromList $ zip srcs textures

data Texture = Texture GLuint
atlasLookup :: Text -> Atlas -> Texture
atlasLookup key = Texture . fromMaybe 0 . HM.lookup key . unAtlas


glFormat (ImageY8 _) = (GL_LUMINANCE, GL_UNSIGNED_BYTE)
glFormat (ImageY16 _) = (GL_LUMINANCE, GL_UNSIGNED_SHORT)
glFormat (ImageY32 _) = (GL_LUMINANCE, GL_UNSIGNED_INT)
glFormat (ImageYF _) = (GL_LUMINANCE, GL_FLOAT)
glFormat (ImageYA8 _) = (GL_LUMINANCE_ALPHA, GL_BYTE)
glFormat (ImageYA16 _) = (GL_LUMINANCE_ALPHA, GL_UNSIGNED_SHORT)
glFormat (ImageRGB8 _) = (GL_RGB, GL_UNSIGNED_BYTE)
glFormat (ImageRGB16 _) = (GL_RGB, GL_UNSIGNED_SHORT)
glFormat (ImageRGBF _) = (GL_RGB, GL_FLOAT)
glFormat (ImageRGBA8 _) = (GL_RGBA, GL_UNSIGNED_BYTE)
glFormat (ImageRGBA16 _) = (GL_RGBA, GL_UNSIGNED_BYTE)
glFormat (ImageYCbCr8 _) = (GL_YCRCB_444_SGIX, GL_UNSIGNED_BYTE)
glFormat (ImageCMYK8 _) = (GL_CMYK_EXT, GL_UNSIGNED_BYTE)
glFormat (ImageCMYK16 _) = (GL_CMYK_EXT, GL_UNSIGNED_SHORT)