Graphics.Caramia.Framebuffer

Framebuffers. You can render on them.

If you come from the OpenGL world, for simplicity, we have combined the concept of draw buffers and color attachments. Nth color attachment is bound exactly to Nth draw buffer. Caramia only talks about draw buffers.

https://www.opengl.org/wiki/Framebuffer_Object

Either OpenGL 3.0 or GL_ARB_framebuffer_object is required for this module.

Creating framebuffers

newFramebuffer :: MonadIO m => [(Attachment, TextureTarget)] -> m Framebuffer

Creates a new framebuffer.

data Framebuffer

Instances

Eq Framebuffer

Ord Framebuffer

OpenGLResource GLuint Framebuffer

Specifying texture targets

frontTextureTarget :: Texture -> TextureTarget

Make a texture target that is the "front" of the given texture.

This is the most common use case. "front" means the first texture in a texture array and the base layer mipmap level.

mipmapTextureTarget

Arguments

:: Texture

-> Int

Which mipmap layer?

-> TextureTarget

Map a specific mipmlayer from a texture.

layerTextureTarget

Arguments

:: Texture

-> Int

Which mipmap layer?

-> Int

Which topological layer?

-> TextureTarget

Map a specific mipmap layer of a specific layer in a 3D or array texture.

data TextureTarget

data Attachment

Constructors

ColorAttachment !Int

DepthAttachment

StencilAttachment

Instances

Eq Attachment

Data Attachment

Ord Attachment

Read Attachment

Show Attachment

Generic Attachment

type Rep Attachment

Size query

getDimensions :: MonadIO m => Framebuffer -> m (Int, Int)

Returns the size of a framebuffer.

This is an IO action because it can change for the screen framebuffer.

Clearing framebuffers

clear :: MonadIO m => Clearing -> Framebuffer -> m ()

Clears values in a framebuffer.

data Clearing

Specifies what to clear in a clear invocation.

Use clearing smart constructor instead for forward-compatibility.

Each member of this data type is a Maybe value; if any value is Just then that value is cleared, otherwise it is not touched.

Constructors

Clearing

Fields

clearDepth :: !(Maybe Float)

Clear depth buffer to this value.

clearStencil :: !(Maybe Int32)

Clear stencil buffer to this value.

clearColor :: !(Maybe Color)

Clear (all) color buffers to some color.

Instances

Eq Clearing

Ord Clearing

Read Clearing

Show Clearing

clearing :: Clearing

Smart constructor for Clearing. All members are Nothing.

Special framebuffers

screenFramebuffer :: Framebuffer

Returns the screen framebuffer.

Note that all screenFramebuffers are equal to each other with Eq, even those in unrelated Caramia contexts.

This makes it easy to check if any framebuffer happens to be the screen framebuffer.

Hardware limits

getMaximumDrawBuffers :: MonadIO m => m Int

Returns the maximum number of draw buffers in the current context.

Almost all GPUs in the last few years have at least 8.

Views

viewTargets :: Framebuffer -> [(Attachment, TextureTarget)]