Crate grr

Bare metal OpenGL 4.5+ wrapper

Overview

grr aims at providing a modern and clean looking API with focus on direct state access. The terminology used follows mostly Vulkan and OpenGL.

Initialization

The main entry point for working with the library is a Device. A device wraps an OpenGL context which needs to be created and managed externally. The documentation and examples will all use glutin for window and context management.

extern crate glutin;
extern crate grr;

use glutin::GlContext;

fn main() -> grr::Result<()> {
    let mut events_loop = glutin::EventsLoop::new();
    let window = glutin::WindowBuilder::new()
        .with_title("Hello grr!")
        .with_dimensions(1024, 768);
    let context = glutin::ContextBuilder::new()
        .with_vsync(true)
        .with_srgb(true)
        .with_gl_debug_flag(true);

    let window = glutin::GlWindow::new(window, context, &events_loop).unwrap();
    unsafe {
        window.make_current().unwrap();
    }

    let grr = grr::Device::new(
        |symbol| window.get_proc_address(symbol) as *const _,
        grr::Debug::Enable {
            callback: |_, _, _, _, msg| {
                println!("{:?}", msg);
            },
            flags: grr::DebugReport::all(),
        },
    );

    Ok(())
}

Modules

The API has multiple concepts which interplay with each other. The main of interacting with the library is via function calls on a Device object. The calls often translate directly to one GL call. All other objects created are opaque handles!

• Resource: Objects with associated memory. Can be a Buffer (untyped) or an Image.
• Pipeline: There currently are two sort of pipelines suppoerted: Graphics and Compute
• Framebuffer: Assembles the attachments (ImageView or RenderBuffer) for draw calls
• Sampler: Configures image filtering. An Image is bound together with a Sampler to a texture unit for access in a shader stage.
• Vertex Array: Specifies the vertex attributes and bindings for the input assembler stage. Buffers are bound to a VertexArray to declare the memory region to fetch attribute data from.

Structs

Barrier	Memory barrier.
BlendChannel
Buffer
BufferRange	Buffer Range.
ColorBlend
ColorBlendAttachment
DebugReport	Debug report flags.
DepthStencil
Device	Logical device, representation one or multiple physical devices (hardware or software).
DeviceFeatures	Additional features supported by the device.
DeviceLimits
DrawIndexedIndirectCmd	Indirect (indexed) draw command structure.
DrawIndirectCmd	Indirect draw command structure.
Extent
Framebuffer	Framebuffer handle.
GraphicsPipelineDesc	Graphics Pipeline Descriptor.
Image	Image resource handle.
ImageView	Image view handle.
InputAssembly	Input Assembly Descriptor.
MappingFlags	Memory mapping flags.
MemoryFlags	Memory property flags.
Multisample
Offset
Pipeline	Graphics or Compute pipeline.
Query
Rasterization	Rasteriyer Descriptor.
Region
RegionBarrier	Memory barrier for by-region dependencies.
Renderbuffer	Renderbuffer handle.
Sampler	Sampler handle.
SamplerDesc	Sampler Descriptor.
Shader	Shader.
StencilFace
SubresourceLayout
SubresourceLevel
SubresourceRange	Subresource of an image.
VertexArray	Vertex array handle.
VertexAttributeDesc
VertexBufferView	Buffer representation for vertex attributes
Viewport	Viewport transformation.

Enums

Attachment	Attachment reference.
AttachmentView
BaseFormat
BlendFactor
BlendOp
ClearAttachment	Attachment clearing description.
Compare	Comparison operator.
ConditionalMode
Constant	Uniform constant.
Debug	Device debug control.
DebugSource	Debug message source.
DebugType	Debug message type.
Error	Error return codes
Filter
Format
FormatLayout
ImageType	Image dimensionality type.
ImageViewType
IndexTy	Index size.
InputRate	Vertex attribute addresssing.
Primitive	Primitve topology.
QueryType
SamplerAddress	Sampler addressing mode.
ShaderStage	Shader Stages.
StencilOp
VertexFormat	Vertex attribute formats.

Functions

as_u8_slice

View a slice as raw byte slice.

Type Definitions

Result

A specialized Result type for grr operations.