Add WebGL.Texture.loadBytesWith

Author: justgook

.eslintrc.json

@@ -40,10 +40,12 @@
         "F4": false,
         "F5": false,
         "F6": false,
+        "F9": false,
         "A2": false,
         "A5": false,
         "Float32Array": false,
         "Int32Array": false,
-        "Uint16Array": false
+        "Uint16Array": false,
+        "Uint8Array": false
     }
 }

elm.json

@@ -14,6 +14,7 @@
     ],
     "elm-version": "0.19.0 <= v < 0.20.0",
     "dependencies": {
+        "elm/bytes": "1.0.8 <= v < 2.0.0",
         "elm/core": "1.0.0 <= v < 2.0.0",
         "elm/html": "1.0.0 <= v < 2.0.0"
     },

src/Elm/Kernel/Texture.js

@@ -65,3 +65,31 @@ var _Texture_load = F6(function (magnify, mininify, horizontalWrap, verticalWrap
 var _Texture_size = function (texture) {
   return __Utils_Tuple2(texture.__width, texture.__height);
 };
+
+
+//Texture Loading from Bytes
+
+// eslint-disable-next-line no-unused-vars
+var _Texture_loadBytes = F9(function (magnify, mininify, horizontalWrap, verticalWrap, flipY, width, height, pixelFormat, bytes) {
+  function createTexture(gl) {
+    var texture = gl.createTexture();
+    gl.bindTexture(gl.TEXTURE_2D, texture);
+    gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, flipY);
+    gl.texImage2D(gl.TEXTURE_2D, 0, pixelFormat, width, height, 0, pixelFormat, gl.UNSIGNED_BYTE, new Uint8Array(bytes.buffer));
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, magnify);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, mininify);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, horizontalWrap);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, verticalWrap);
+    if (mininify !== 9728 && mininify !== 9729) {
+      gl.generateMipmap(gl.TEXTURE_2D);
+    }
+    gl.bindTexture(gl.TEXTURE_2D, null);
+    return texture;
+  }
+  return {
+    $: __0_TEXTURE,
+    __$createTexture: createTexture,
+    __width: width,
+    __height: height
+  };
+});

src/WebGL/Texture.elm

@@ -21,6 +21,10 @@ module WebGL.Texture
         , nonPowerOfTwoOptions
         , repeat
         , size
+        , Format
+        , loadBytesWith
+        , unsafeLoad
+        , rgb , rgba, luminanceAlpha, luminance, alpha
         )
 
 {-|
@@ -51,10 +55,11 @@ module WebGL.Texture
 
 # Things You Shouldn’t Do
 
-@docs nonPowerOfTwoOptions
+@docs nonPowerOfTwoOptions, loadBytesWith, unsafeLoad, Format, rgb , rgba, luminanceAlpha, luminance, alpha
 
 -}
-
+import Bitwise
+import Bytes exposing (Bytes)
 import Elm.Kernel.Texture
 import Task exposing (Task)
 
@@ -304,3 +309,110 @@ or other times you may want to use only a potion of a texture image.
 size : Texture -> ( Int, Int )
 size =
     Elm.Kernel.Texture.size
+
+
+
+{-| Building [`Texture`](#Texture) from bytes
+
+  - [`Options`](#Options) - same as for [`loadWith`](#loadWith)
+
+  - `(width, height)` - dimensions of new created texture
+
+  - [`Format`](#Format) - pixel format in bytes
+
+  - Bytes - encoded pixels, where `Bytes.width` > `width` \* `height` \* `Bytes per pixe`or you get `SizeError`
+
+Do not generate texture in `view`, [read more about this here](https://package.elm-lang.org/packages/elm-explorations/webgl/latest#making-the-most-of-the-gpu).
+
+-}
+loadBytesWith :
+    Options
+    -> ( Int, Int )
+    -> Format
+    -> Bytes
+    -> Result Error Texture
+loadBytesWith ({ magnify, minify, horizontalWrap, verticalWrap, flipY } as opt) ( w, h ) ((Format _ bytesPerPixel) as format) b =
+    let
+        isMipmap =
+            minify /= nearest && minify /= linear
+
+        widthPowerOfTwo =
+            Bitwise.and (w - 1) w == 0
+
+        heightPowerOfTwo =
+            Bitwise.and (h - 1) h == 0
+
+        isSizeValid =
+            (widthPowerOfTwo && heightPowerOfTwo) || (not isMipmap && horizontalWrap == clampToEdge && verticalWrap == clampToEdge)
+    in
+    if w > 0 && h > 0 && isSizeValid && Bytes.width b >= w * h * bytesPerPixel then
+        Ok (unsafeLoad opt ( w, h ) format b)
+
+    else
+        Err (SizeError w h)
+
+
+{-| It is intended specifically for library writers who want to create custom texture loaders.
+-}
+unsafeLoad :
+    Options
+    -> ( Int, Int )
+    -> Format
+    -> Bytes
+    -> Texture
+unsafeLoad { magnify, minify, horizontalWrap, verticalWrap, flipY } ( w, h ) (Format format _) b =
+    let
+        expand (Resize mag) (Resize min) (Wrap hor) (Wrap vert) =
+            Elm.Kernel.Texture.loadBytes mag min hor vert flipY w h format b
+    in
+    expand magnify minify horizontalWrap verticalWrap
+
+{-| How to read bytes intpo pixel
+
+        | Format          | Channels | Bytes per pixel |
+        ------------------------------------------------
+        | rgba            |    4     |        4        |
+        | rgb             |    3     |        3        |
+        | luminanceAlpha  |    2     |        2        |
+        | luminance       |    1     |        1        |
+        | alpha           |    1     |        1        |
+        ------------------------------------------------
+
+-}
+type Format
+    = Format Int Int
+
+
+{-| Single pixel is 4 bytes long and have 4 channels
+-}
+rgba : Format
+rgba =
+    Format 6408 4
+
+
+{-| Single pixel is 3 bytes long and have 3 channels
+-}
+rgb : Format
+rgb =
+    Format 6407 3
+
+
+{-| Single pixel is 2 bytes long and have 2 channels
+-}
+luminanceAlpha : Format
+luminanceAlpha =
+    Format 6410 2
+
+
+{-| Single pixel is 1 bytes long and have 1 channels
+-}
+luminance : Format
+luminance =
+    Format 6409 1
+
+
+{-| Single pixel is 1 bytes long and have 1 channels
+-}
+alpha : Format
+alpha =
+    Format 6406 1