diff --git a/Graphics/GL/Low.hs b/Graphics/GL/Low.hs --- a/Graphics/GL/Low.hs +++ b/Graphics/GL/Low.hs @@ -70,7 +70,7 @@ -- vbo <- newVBO blob StaticDraw -- bindVBO vbo -- -- connect program to vertex data via the VAO - -- setVertexAttributeLayout [Attrib "position" 2 VFloat] + -- setVertexLayout [Attrib "position" 2 GLFloat] -- return (vao, prog) -- -- draw vao prog = do @@ -159,7 +159,7 @@ -- -- After installing a program with 'useProgram' and binding a source VBO -- to the array buffer binding target ('bindVBO') then the bound VAO can be - -- updated ('setVertexAttributeLayout') with new vertex attribute information. + -- updated ('setVertexLayout') with new vertex attribute information. -- After this, the VBO can be rebound to configure a different set of inputs -- with a different source. Many VAOs can be created and swapped out to pipe -- vertex data in different ways to different programs (or the same program). @@ -327,10 +327,9 @@ -- ** Vertex Attributes -- | See also "Graphics.GL.Low.VertexAttrib" - setVertexAttributeLayout, - VertexAttributeLayout(..), - LayoutElement(..), - ComponentFormat(..), + setVertexLayout, + VertexLayout(..), + DataType(..), -- * Textures diff --git a/Graphics/GL/Low/Blending.hs b/Graphics/GL/Low/Blending.hs --- a/Graphics/GL/Low/Blending.hs +++ b/Graphics/GL/Low/Blending.hs @@ -60,7 +60,7 @@ -- , -0.5, -0.5 ] :: V.Vector Float -- vbo <- newVBO blob StaticDraw -- bindVBO vbo --- setVertexAttributeLayout [Attrib "position" 2 VFloat] +-- setVertexLayout [Attrib "position" 2 GLFloat] -- enableBlending basicBlending -- return (vao, prog) -- diff --git a/Graphics/GL/Low/Shader.hs b/Graphics/GL/Low/Shader.hs --- a/Graphics/GL/Low/Shader.hs +++ b/Graphics/GL/Low/Shader.hs @@ -78,9 +78,9 @@ -- , 0.4, -0.4, 1, 1] :: V.Vector Float -- vbo <- newVBO blob StaticDraw -- bindVBO vbo --- setVertexAttributeLayout --- [ Attrib "position" 2 VFloat --- , Attrib "location" 2 VFloat ] +-- setVertexLayout +-- [ Attrib "position" 2 GLFloat +-- , Attrib "location" 2 GLFloat ] -- return (vao, prog1, prog2, prog3) -- -- draw vao prog1 prog2 prog3 t = do diff --git a/Graphics/GL/Low/VAO.hs b/Graphics/GL/Low/VAO.hs --- a/Graphics/GL/Low/VAO.hs +++ b/Graphics/GL/Low/VAO.hs @@ -12,7 +12,7 @@ -- - Bind a VAO -- - Bind a VBO -- - Use a Program --- - call 'Graphics.GL.Low.VertexAttrib.setVertexAttributeLayout' which will +-- - call 'Graphics.GL.Low.VertexAttrib.setVertexLayout' which will -- lookup the position of the input variables and issue the appropriate -- glVertexAttribPointer calls. -- diff --git a/Graphics/GL/Low/VertexAttrib.hs b/Graphics/GL/Low/VertexAttrib.hs --- a/Graphics/GL/Low/VertexAttrib.hs +++ b/Graphics/GL/Low/VertexAttrib.hs @@ -1,6 +1,30 @@ --- | Vertex Attribute Array. -module Graphics.GL.Low.VertexAttrib where +-- | To feed vertices into the vertex shader, the layout of a vertex must be +-- specified in the current VAO for the current shader program. Make a list of +-- LayoutElements and use 'setVertexLayout' on it as seen below. +-- +-- == Example +-- +-- @ +-- setVertexLayout +-- [ Attrib "position" 3 GLFloat -- first 12 bytes maps to: in vec3 position; +-- , Attrib "shininess" 1 GLFloat -- next 4 bytes maps to: in float shininess; +-- , Attrib "texcoord" 2 GLFloat -- next 8 bytes maps to: in vec2 texcoord; +-- , Unused 2 -- next 2 bytes ignored +-- , Attrib "seed" 1 GLShort ] -- next 2 bytes read as 16-bit signed int +-- -- and mapped to: in float seed; +-- @ +-- +-- In this example four mappings from the current VBO to the variables +-- in the current Program will be established in the current VAO. + +module Graphics.GL.Low.VertexAttrib ( + setVertexLayout, + VertexLayout(..), + DataType(..) +) where + + import Foreign.C.String import Foreign.Ptr import Foreign.Marshal @@ -8,106 +32,33 @@ import Control.Monad (forM_) import Graphics.GL - import Graphics.GL.Low.Classes -- | The name of a vertex input to a program combined with the -- component format and number of components for that attribute in the -- vertex data. Alternatively the size of an unused section of the data -- in bytes. -data LayoutElement = - Attrib String Int ComponentFormat | -- ^ Name, component count and component format of a vertex attribute. +data VertexLayout = + Attrib String Int DataType | -- ^ Name, component count and component format of a vertex attribute. Unused Int -- ^ Size in bytes of an unused section of the vertex data. deriving Show --- | The layout of interleaved vertex attribute data. -type VertexAttributeLayout = [LayoutElement] - -- | The size and interpretation of a vertex attribute component. Normalized -- components will be mapped to floats in the range [0, 1]. -data ComponentFormat = - VFloat | -- ^ 4-byte float - VByte | - VUByte | - VByteNormalized | - VUByteNormalized | - VShort | -- ^ 2-byte signed integer - VUShort | -- ^ 2-byte unsigned integer - VShortNormalized | - VUShortNormalized | - VInt | -- ^ 4-byte signed integer - VUInt | -- ^ 4-byte unsigned integer - VIntNormalized | - VUIntNormalized +data DataType = + GLFloat | -- ^ 4-byte float + GLUnsignedByte | -- ^ unsigned byte + GLByte | -- ^ signed byte + GLShort | -- ^ 2-byte signed integer + GLUnsignedShort | -- ^ 2-byte unsigned integer + GLInt | -- ^ 4-byte signed integer + GLUnsignedInt -- ^ 4-byte unsigned integer deriving (Eq, Show) -instance ToGL ComponentFormat where - toGL VFloat = GL_FLOAT - toGL VByte = GL_BYTE - toGL VUByte = GL_UNSIGNED_BYTE - toGL VByteNormalized = GL_BYTE - toGL VUByteNormalized = GL_UNSIGNED_BYTE - toGL VShort = GL_SHORT - toGL VUShort = GL_UNSIGNED_SHORT - toGL VShortNormalized = GL_SHORT - toGL VUShortNormalized = GL_UNSIGNED_SHORT - toGL VInt = GL_INT - toGL VUInt = GL_UNSIGNED_INT - toGL VIntNormalized = GL_INT - toGL VUIntNormalized = GL_UNSIGNED_INT - - - -elaborateLayout :: Int -> VertexAttributeLayout -> [(String, Int, Int, ComponentFormat)] -elaborateLayout here layout = case layout of - [] -> [] - (Unused n):xs -> elaborateLayout (here+n) xs - (Attrib name n fmt):xs -> - let size = n * sizeOfVertexComponent fmt in - (name, n, here, fmt) : elaborateLayout (here+size) xs - -totalLayout :: VertexAttributeLayout -> Int -totalLayout layout = sum (map arraySize layout) where - arraySize (Unused n) = n - arraySize (Attrib _ n fmt) = n * sizeOfVertexComponent fmt - -sizeOfVertexComponent :: ComponentFormat -> Int -sizeOfVertexComponent c = case c of - VByte -> 1 - VUByte -> 1 - VByteNormalized -> 1 - VUByteNormalized -> 1 - VShort -> 2 - VUShort -> 2 - VShortNormalized -> 2 - VUShortNormalized -> 2 - VInt -> 4 - VUInt -> 4 - VIntNormalized -> 4 - VUIntNormalized -> 4 - VFloat -> 4 - -isNormalized :: ComponentFormat -> Bool -isNormalized c = case c of - VByte -> False - VUByte -> False - VByteNormalized -> True - VUByteNormalized -> True - VShort -> False - VUShort -> False - VShortNormalized -> True - VUShortNormalized -> True - VInt -> False - VUInt -> False - VIntNormalized -> True - VUIntNormalized -> True - VFloat -> False - - -- | This configures the currently bound VAO. It calls glVertexAttribPointer -- and glEnableVertexAttribArray. -setVertexAttributeLayout :: VertexAttributeLayout -> IO () -setVertexAttributeLayout layout = do +setVertexLayout :: [VertexLayout] -> IO () +setVertexLayout layout = do p <- alloca (\ptr -> glGetIntegerv GL_CURRENT_PROGRAM ptr >> peek ptr) if p == 0 then return () @@ -116,18 +67,49 @@ let total = totalLayout layout forM_ layout' $ \(name, size, offset, fmt) -> do attrib <- withCString name $ \ptr -> glGetAttribLocation (fromIntegral p) (castPtr ptr) - --let stride = total - size * sizeOfVertexComponent fmt let stride = total - let norm = isNormalized fmt glVertexAttribPointer (fromIntegral attrib) (fromIntegral size) (toGL fmt) - (toGL norm) + GL_FALSE (fromIntegral stride) (castPtr (nullPtr `plusPtr` offset)) glEnableVertexAttribArray (fromIntegral attrib) + +instance ToGL DataType where + toGL GLFloat = GL_FLOAT + toGL GLByte = GL_BYTE + toGL GLUnsignedByte = GL_UNSIGNED_BYTE + toGL GLShort = GL_SHORT + toGL GLUnsignedShort = GL_UNSIGNED_SHORT + toGL GLInt = GL_INT + toGL GLUnsignedInt = GL_UNSIGNED_INT + instance ToGL Bool where toGL True = GL_TRUE toGL False = GL_FALSE + +elaborateLayout :: Int -> [VertexLayout] -> [(String, Int, Int, DataType)] +elaborateLayout here layout = case layout of + [] -> [] + (Unused n):xs -> elaborateLayout (here+n) xs + (Attrib name n ty):xs -> + let size = n * sizeOfType ty in + (name, n, here, ty) : elaborateLayout (here+size) xs + +totalLayout :: [VertexLayout] -> Int +totalLayout layout = sum (map arraySize layout) where + arraySize (Unused n) = n + arraySize (Attrib _ n ty) = n * sizeOfType ty + +sizeOfType :: DataType -> Int +sizeOfType c = case c of + GLFloat -> 4 + GLByte -> 1 + GLUnsignedByte -> 1 + GLShort -> 2 + GLUnsignedShort -> 2 + GLInt -> 4 + GLUnsignedInt -> 4 diff --git a/lowgl.cabal b/lowgl.cabal --- a/lowgl.cabal +++ b/lowgl.cabal @@ -10,7 +10,7 @@ -- PVP summary: +-+------- breaking API changes -- | | +----- non-breaking API additions -- | | | +--- code changes with no API change -version: 0.2.1.1 +version: 0.3.0.0 -- A short (one-line) description of the package. synopsis: Basic gl wrapper and reference @@ -89,4 +89,4 @@ source-repository this type: git location: https://github.com/evanrinehart/lowgl - tag: 0.2.1.1 + tag: 0.3.0.0