gles

package
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 Go to latest Published: Apr 25, 2026 License: MIT Imports: 13 Imported by: 1

Documentation

Overview

Package gles implements the HAL backend for OpenGL ES 3.0 / OpenGL 3.3+.

This backend provides a Pure Go implementation using syscall directly, without any CGO or external dependencies.

Platform Support

Currently supported:

  • Windows (WGL) - via hal/gles/wgl package

Planned:

  • Linux (GLX/EGL)
  • macOS (CGL/EGL)
  • Android (EGL)
  • WebGL (via wasm)

Architecture

The backend is organized into subpackages: 

hal/gles/
├── gl/       - OpenGL function bindings
├── wgl/      - Windows GL context management
├── glx/      - Linux X11 GL context (planned)
├── egl/      - EGL context for mobile/modern Linux (planned)
└── cgl/      - macOS CGL context (planned)

Usage

Import this package to register the OpenGL backend: 

import _ "github.com/gogpu/wgpu/hal/gles"

The backend is then available via hal.GetBackend(types.BackendGL).

OpenGL Version Requirements

Minimum requirements:

  • OpenGL 3.3 Core Profile (desktop)
  • OpenGL ES 3.0 (mobile/embedded)

The backend queries actual capabilities at runtime and adjusts feature availability accordingly.

Limitations

Compared to Vulkan/Metal/DX12:

  • No async compute (compute runs on graphics queue)
  • Limited bindless resource support
  • Single command queue
  • Synchronous texture uploads

Command Recording

This backend uses a command recording pattern similar to wgpu-hal. Commands are recorded during render/compute pass encoding and executed during Queue.Submit. This allows for:

  • State tracking and optimization
  • Better error handling
  • Potential future multithreading

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

This section is empty.

Types

type Adapter 

type Adapter struct {
	// contains filtered or unexported fields
}

Adapter implements hal.Adapter for OpenGL on Linux.

func (*Adapter) Destroy 

func (a *Adapter) Destroy()

Destroy releases the adapter.

func (*Adapter) Open 

func (a *Adapter) Open(_ gputypes.Features, _ gputypes.Limits) (hal.OpenDevice, error)

Open creates a logical device with the requested features and limits.

func (*Adapter) SurfaceCapabilities 

func (a *Adapter) SurfaceCapabilities(_ hal.Surface) *hal.SurfaceCapabilities

SurfaceCapabilities returns surface capabilities.

func (*Adapter) TextureFormatCapabilities 

func (a *Adapter) TextureFormatCapabilities(format gputypes.TextureFormat) hal.TextureFormatCapabilities

TextureFormatCapabilities returns capabilities for a texture format.

type AttachDepthStencilCommand added in v0.16.0 

type AttachDepthStencilCommand struct {
	// contains filtered or unexported fields
}

AttachDepthStencilCommand attaches a depth/stencil texture to the currently bound FBO (the one associated with the color texture). This must be recorded after EnsureOffscreenFBOCommand so the FBO is already bound.

func (*AttachDepthStencilCommand) Execute added in v0.16.0 

func (c *AttachDepthStencilCommand) Execute(ctx *gl.Context)

type Backend 

type Backend struct{}

Backend implements hal.Backend for OpenGL ES / OpenGL 3.3+ on Linux.

func (Backend) CreateInstance 

func (Backend) CreateInstance(_ *hal.InstanceDescriptor) (hal.Instance, error)

CreateInstance creates a new OpenGL instance.

func (Backend) Variant 

func (Backend) Variant() gputypes.Backend

Variant returns the backend type identifier.

type BindFramebufferCommand added in v0.16.0 

type BindFramebufferCommand struct {
	// contains filtered or unexported fields
}

BindFramebufferCommand binds a framebuffer object.

func (*BindFramebufferCommand) Execute added in v0.16.0 

func (c *BindFramebufferCommand) Execute(ctx *gl.Context)

type BindGroup 

type BindGroup struct {
	// contains filtered or unexported fields
}

BindGroup implements hal.BindGroup for OpenGL.

func (*BindGroup) Destroy 

func (g *BindGroup) Destroy()

Destroy is a no-op for bind groups.

type BindGroupDescriptor 

type BindGroupDescriptor = hal.BindGroupDescriptor

Type aliases for hal descriptors

type BindGroupLayout 

type BindGroupLayout struct {
	// contains filtered or unexported fields
}

BindGroupLayout implements hal.BindGroupLayout for OpenGL.

func (*BindGroupLayout) Destroy 

func (l *BindGroupLayout) Destroy()

Destroy is a no-op for bind group layouts.

type BindGroupLayoutDescriptor 

type BindGroupLayoutDescriptor = hal.BindGroupLayoutDescriptor

Type aliases for hal descriptors

type BindGroupLayoutInfo added in v0.23.8 

type BindGroupLayoutInfo struct {
	BindingToSlot []uint8 // indexed by binding number, 0xFF = unused
}

BindGroupLayoutInfo stores per-group binding-to-slot mapping computed at PipelineLayout creation time. Matches Rust wgpu-hal BindGroupLayoutInfo. Each entry in BindingToSlot is indexed by the WGSL binding number and maps to the sequential GL slot index for that resource type. 0xFF means unused.

type BindSurfaceFramebufferCommand added in v0.25.0 

type BindSurfaceFramebufferCommand struct {
	// contains filtered or unexported fields
}

BindSurfaceFramebufferCommand binds the Surface's swapchain offscreen framebuffer. Reads surface.swapchainFBO at execute time so reconfigure (e.g. window resize) between encode and submit is handled correctly. Mirrors Rust wgpu-hal/src/gles/egl.rs Surface::configure swapchain FBO.

func (*BindSurfaceFramebufferCommand) Execute added in v0.25.0 

func (c *BindSurfaceFramebufferCommand) Execute(ctx *gl.Context)

type BindVAOCommand added in v0.16.0 

type BindVAOCommand struct {
	// contains filtered or unexported fields
}

BindVAOCommand binds a vertex array object.

func (*BindVAOCommand) Execute added in v0.16.0 

func (c *BindVAOCommand) Execute(ctx *gl.Context)

type Buffer 

type Buffer struct {
	// contains filtered or unexported fields
}

Buffer implements hal.Buffer for OpenGL.

func (*Buffer) Destroy 

func (b *Buffer) Destroy()

Destroy releases the buffer.

func (*Buffer) NativeHandle added in v0.12.0 

func (b *Buffer) NativeHandle() uintptr

NativeHandle returns the GL buffer object ID.

type BufferDescriptor 

type BufferDescriptor = hal.BufferDescriptor

Type aliases for hal descriptors

type ClearBufferCommand 

type ClearBufferCommand struct {
	// contains filtered or unexported fields
}

ClearBufferCommand clears a buffer region.

func (*ClearBufferCommand) Execute 

func (c *ClearBufferCommand) Execute(_ *gl.Context)

type ClearColorCommand 

type ClearColorCommand struct {
	// contains filtered or unexported fields
}

ClearColorCommand clears a color attachment.

func (*ClearColorCommand) Execute 

func (c *ClearColorCommand) Execute(ctx *gl.Context)

type ClearDepthCommand 

type ClearDepthCommand struct {
	// contains filtered or unexported fields
}

ClearDepthCommand clears the depth buffer.

func (*ClearDepthCommand) Execute 

func (c *ClearDepthCommand) Execute(ctx *gl.Context)

type ClearStencilCommand 

type ClearStencilCommand struct {
	// contains filtered or unexported fields
}

ClearStencilCommand clears the stencil buffer.

func (*ClearStencilCommand) Execute 

func (c *ClearStencilCommand) Execute(ctx *gl.Context)

type Command 

type Command interface {
	Execute(ctx *gl.Context)
}

Command represents a recorded GL command.

type CommandBuffer 

type CommandBuffer struct {
	// contains filtered or unexported fields
}

CommandBuffer holds recorded commands for later execution.

func (*CommandBuffer) Destroy 

func (c *CommandBuffer) Destroy()

Destroy releases the command buffer resources.

type CommandEncoder 

type CommandEncoder struct {
	// contains filtered or unexported fields
}

CommandEncoder implements hal.CommandEncoder for OpenGL. Platform-specific fields are defined in command_<platform>.go files.

func (*CommandEncoder) BeginComputePass 

func (e *CommandEncoder) BeginComputePass(_ *hal.ComputePassDescriptor) hal.ComputePassEncoder

BeginComputePass begins a compute pass.

func (*CommandEncoder) BeginEncoding 

func (e *CommandEncoder) BeginEncoding(label string) error

BeginEncoding begins command recording.

func (*CommandEncoder) BeginRenderPass 

func (e *CommandEncoder) BeginRenderPass(desc *hal.RenderPassDescriptor) hal.RenderPassEncoder

BeginRenderPass begins a render pass.

func (*CommandEncoder) ClearBuffer 

func (e *CommandEncoder) ClearBuffer(buffer hal.Buffer, offset, size uint64)

ClearBuffer clears a buffer region to zero.

func (*CommandEncoder) CopyBufferToBuffer 

func (e *CommandEncoder) CopyBufferToBuffer(src, dst hal.Buffer, regions []hal.BufferCopy)

CopyBufferToBuffer copies data between buffers.

func (*CommandEncoder) CopyBufferToTexture 

func (e *CommandEncoder) CopyBufferToTexture(src hal.Buffer, dst hal.Texture, regions []hal.BufferTextureCopy)

CopyBufferToTexture copies buffer data to a texture. Note: Requires glTexSubImage2D with pixel unpack buffer binding. Currently a no-op stub - texture uploads should use Queue.WriteTexture.

func (*CommandEncoder) CopyTextureToBuffer 

func (e *CommandEncoder) CopyTextureToBuffer(src hal.Texture, dst hal.Buffer, regions []hal.BufferTextureCopy)

CopyTextureToBuffer copies texture data to a buffer via FBO + glReadPixels. For each region, it binds the source texture's FBO and reads pixels into the destination buffer's CPU-side data slice.

func (*CommandEncoder) CopyTextureToTexture 

func (e *CommandEncoder) CopyTextureToTexture(src, dst hal.Texture, regions []hal.TextureCopy)

CopyTextureToTexture copies between textures. Note: Requires glCopyImageSubData (GL 4.3+ / GLES 3.2+). For older GL versions, requires framebuffer blit workaround.

func (*CommandEncoder) Destroy added in v0.23.4 

func (e *CommandEncoder) Destroy()

Destroy is a no-op for OpenGL (no persistent GPU resources owned by encoder).

func (*CommandEncoder) DiscardEncoding 

func (e *CommandEncoder) DiscardEncoding()

DiscardEncoding discards the encoder.

func (*CommandEncoder) EndEncoding 

func (e *CommandEncoder) EndEncoding() (hal.CommandBuffer, error)

EndEncoding finishes command recording and returns a command buffer.

func (*CommandEncoder) ResetAll 

func (e *CommandEncoder) ResetAll(_ []hal.CommandBuffer)

ResetAll resets command buffers for reuse.

func (*CommandEncoder) ResolveQuerySet added in v0.16.4 

func (e *CommandEncoder) ResolveQuerySet(_ hal.QuerySet, _, _ uint32, _ hal.Buffer, _ uint64)

ResolveQuerySet copies query results from a query set into a destination buffer. TODO: implement using GL_EXT_disjoint_timer_query when query sets are supported.

func (*CommandEncoder) TransitionBuffers 

func (e *CommandEncoder) TransitionBuffers(_ []hal.BufferBarrier)

TransitionBuffers transitions buffer states.

func (*CommandEncoder) TransitionTextures 

func (e *CommandEncoder) TransitionTextures(_ []hal.TextureBarrier)

TransitionTextures transitions texture states.

type CommandEncoderDescriptor 

type CommandEncoderDescriptor = hal.CommandEncoderDescriptor

Type aliases for hal descriptors

type ComputePassEncoder 

type ComputePassEncoder struct {
	// contains filtered or unexported fields
}

ComputePassEncoder implements hal.ComputePassEncoder for OpenGL.

func (*ComputePassEncoder) Dispatch 

func (e *ComputePassEncoder) Dispatch(x, y, z uint32)

Dispatch dispatches compute work.

func (*ComputePassEncoder) DispatchIndirect 

func (e *ComputePassEncoder) DispatchIndirect(buffer hal.Buffer, offset uint64)

DispatchIndirect dispatches compute work with GPU-generated parameters.

func (*ComputePassEncoder) End 

func (e *ComputePassEncoder) End()

End finishes the compute pass.

func (*ComputePassEncoder) SetBindGroup 

func (e *ComputePassEncoder) SetBindGroup(index uint32, group hal.BindGroup, offsets []uint32)

SetBindGroup sets a bind group.

func (*ComputePassEncoder) SetPipeline 

func (e *ComputePassEncoder) SetPipeline(pipeline hal.ComputePipeline)

SetPipeline sets the compute pipeline.

type ComputePipeline 

type ComputePipeline struct {
	// contains filtered or unexported fields
}

ComputePipeline implements hal.ComputePipeline for OpenGL.

func (*ComputePipeline) Destroy 

func (p *ComputePipeline) Destroy()

Destroy releases the compute pipeline.

type ComputePipelineDescriptor 

type ComputePipelineDescriptor = hal.ComputePipelineDescriptor

Type aliases for hal descriptors

type CopyBufferCommand 

type CopyBufferCommand struct {
	// contains filtered or unexported fields
}

CopyBufferCommand copies between buffers.

func (*CopyBufferCommand) Execute 

func (c *CopyBufferCommand) Execute(ctx *gl.Context)

type CopyTextureToBufferCommand added in v0.16.0 

type CopyTextureToBufferCommand struct {
	// contains filtered or unexported fields
}

CopyTextureToBufferCommand reads pixels from a texture's FBO into a buffer's CPU-side data slice. This is the standard GLES readback path since GLES lacks glGetTexImage. The approach: bind texture FBO -> glReadPixels -> copy to buffer.

func (*CopyTextureToBufferCommand) Execute added in v0.16.0 

func (c *CopyTextureToBufferCommand) Execute(ctx *gl.Context)

Execute reads pixels from the source texture's FBO into the destination buffer.

type Device 

type Device struct {
	// contains filtered or unexported fields
}

Device implements hal.Device for OpenGL on Linux.

func (*Device) CreateBindGroup 

func (d *Device) CreateBindGroup(desc *BindGroupDescriptor) (hal.BindGroup, error)

CreateBindGroup creates a bind group.

func (*Device) CreateBindGroupLayout 

func (d *Device) CreateBindGroupLayout(desc *BindGroupLayoutDescriptor) (hal.BindGroupLayout, error)

CreateBindGroupLayout creates a bind group layout.

func (*Device) CreateBuffer 

func (d *Device) CreateBuffer(desc *BufferDescriptor) (hal.Buffer, error)

CreateBuffer creates a GPU buffer.

func (*Device) CreateCommandEncoder 

func (d *Device) CreateCommandEncoder(_ *CommandEncoderDescriptor) (hal.CommandEncoder, error)

CreateCommandEncoder creates a command encoder.

func (*Device) CreateComputePipeline 

func (d *Device) CreateComputePipeline(desc *ComputePipelineDescriptor) (hal.ComputePipeline, error)

CreateComputePipeline creates a compute pipeline.

func (*Device) CreateFence 

func (d *Device) CreateFence() (hal.Fence, error)

CreateFence creates a synchronization fence.

func (*Device) CreatePipelineLayout 

func (d *Device) CreatePipelineLayout(desc *PipelineLayoutDescriptor) (hal.PipelineLayout, error)

CreatePipelineLayout creates a pipeline layout. Computes per-type sequential binding indices following the Rust wgpu-hal pattern (wgpu-hal/src/gles/device.rs:1154-1221). Five resource type counters (samplers, textures, images, uniform buffers, storage buffers) are incremented sequentially across all bind group layouts, producing a flat GL slot index per binding.

func (*Device) CreateQuerySet added in v0.16.4 

func (d *Device) CreateQuerySet(_ *hal.QuerySetDescriptor) (hal.QuerySet, error)

CreateQuerySet creates a query set. TODO: implement using GL_EXT_disjoint_timer_query for timestamp support.

func (*Device) CreateRenderBundleEncoder added in v0.13.0 

func (d *Device) CreateRenderBundleEncoder(desc *hal.RenderBundleEncoderDescriptor) (hal.RenderBundleEncoder, error)

CreateRenderBundleEncoder is not supported in GLES backend.

func (*Device) CreateRenderPipeline 

func (d *Device) CreateRenderPipeline(desc *RenderPipelineDescriptor) (hal.RenderPipeline, error)

CreateRenderPipeline creates a render pipeline.

func (*Device) CreateSampler 

func (d *Device) CreateSampler(desc *SamplerDescriptor) (hal.Sampler, error)

CreateSampler creates a texture sampler using GL sampler objects (GL 3.3+).

func (*Device) CreateShaderModule 

func (d *Device) CreateShaderModule(desc *ShaderModuleDescriptor) (hal.ShaderModule, error)

CreateShaderModule creates a shader module.

func (*Device) CreateTexture 

func (d *Device) CreateTexture(desc *TextureDescriptor) (hal.Texture, error)

CreateTexture creates a GPU texture.

func (*Device) CreateTextureView 

func (d *Device) CreateTextureView(texture hal.Texture, desc *TextureViewDescriptor) (hal.TextureView, error)

CreateTextureView creates a view into a texture. Accepts both *Texture and *SurfaceTexture (default framebuffer).

func (*Device) Destroy 

func (d *Device) Destroy()

Destroy releases the device.

func (*Device) DestroyBindGroup 

func (d *Device) DestroyBindGroup(group hal.BindGroup)

DestroyBindGroup destroys a bind group.

func (*Device) DestroyBindGroupLayout 

func (d *Device) DestroyBindGroupLayout(layout hal.BindGroupLayout)

DestroyBindGroupLayout destroys a bind group layout.

func (*Device) DestroyBuffer 

func (d *Device) DestroyBuffer(buffer hal.Buffer)

DestroyBuffer destroys a GPU buffer.

func (*Device) DestroyComputePipeline 

func (d *Device) DestroyComputePipeline(pipeline hal.ComputePipeline)

DestroyComputePipeline destroys a compute pipeline.

func (*Device) DestroyFence 

func (d *Device) DestroyFence(fence hal.Fence)

DestroyFence destroys a fence.

func (*Device) DestroyPipelineLayout 

func (d *Device) DestroyPipelineLayout(layout hal.PipelineLayout)

DestroyPipelineLayout destroys a pipeline layout.

func (*Device) DestroyQuerySet added in v0.16.4 

func (d *Device) DestroyQuerySet(_ hal.QuerySet)

DestroyQuerySet destroys a query set.

func (*Device) DestroyRenderBundle added in v0.13.0 

func (d *Device) DestroyRenderBundle(bundle hal.RenderBundle)

DestroyRenderBundle is not supported in GLES backend.

func (*Device) DestroyRenderPipeline 

func (d *Device) DestroyRenderPipeline(pipeline hal.RenderPipeline)

DestroyRenderPipeline destroys a render pipeline.

func (*Device) DestroySampler 

func (d *Device) DestroySampler(sampler hal.Sampler)

DestroySampler destroys a sampler.

func (*Device) DestroyShaderModule 

func (d *Device) DestroyShaderModule(module hal.ShaderModule)

DestroyShaderModule destroys a shader module.

func (*Device) DestroyTexture 

func (d *Device) DestroyTexture(texture hal.Texture)

DestroyTexture destroys a GPU texture.

func (*Device) DestroyTextureView 

func (d *Device) DestroyTextureView(view hal.TextureView)

DestroyTextureView destroys a texture view.

func (*Device) FreeCommandBuffer added in v0.13.0 

func (d *Device) FreeCommandBuffer(cmdBuffer hal.CommandBuffer)

FreeCommandBuffer is a no-op for GLES. GLES doesn't have Vulkan-style command pools - commands are recorded directly.

func (*Device) GetFenceStatus added in v0.13.0 

func (d *Device) GetFenceStatus(fence hal.Fence) (bool, error)

GetFenceStatus returns true if the fence is signaled (non-blocking).

func (*Device) MapBuffer added in v0.25.0 

func (d *Device) MapBuffer(buffer hal.Buffer, offset, size uint64) (hal.BufferMapping, error)

MapBuffer establishes a CPU-visible mapping for a GL buffer via a CPU shadow slice. See device.go (Windows variant) for rationale.

func (*Device) ResetFence added in v0.13.0 

func (d *Device) ResetFence(fence hal.Fence) error

ResetFence resets a fence to the unsignaled state.

func (*Device) UnmapBuffer added in v0.25.0 

func (d *Device) UnmapBuffer(buffer hal.Buffer) error

UnmapBuffer releases a GL buffer mapping. Writable buffers push the shadow back into the GL buffer via glBufferSubData; the shadow is then released so subsequent MapBuffer calls pick up fresh contents.

func (*Device) Wait 

func (d *Device) Wait(fence hal.Fence, value uint64, timeout time.Duration) (bool, error)

Wait waits for a fence to reach the specified value.

func (*Device) WaitIdle added in v0.16.3 

func (d *Device) WaitIdle() error

WaitIdle waits for all GPU work to complete.

type DispatchCommand 

type DispatchCommand struct {
	// contains filtered or unexported fields
}

DispatchCommand dispatches compute work.

func (*DispatchCommand) Execute 

func (c *DispatchCommand) Execute(ctx *gl.Context)

Execute dispatches compute work and inserts a memory barrier.

type DispatchIndirectCommand added in v0.8.1 

type DispatchIndirectCommand struct {
	// contains filtered or unexported fields
}

DispatchIndirectCommand dispatches compute work with GPU-generated parameters.

func (*DispatchIndirectCommand) Execute added in v0.8.1 

func (c *DispatchIndirectCommand) Execute(ctx *gl.Context)

Execute dispatches compute work from indirect buffer and inserts a memory barrier.

type DrawCommand 

type DrawCommand struct {
	// contains filtered or unexported fields
}

DrawCommand executes a non-indexed draw.

func (*DrawCommand) Execute 

func (c *DrawCommand) Execute(ctx *gl.Context)

type DrawIndexedCommand 

type DrawIndexedCommand struct {
	// contains filtered or unexported fields
}

DrawIndexedCommand executes an indexed draw.

func (*DrawIndexedCommand) Execute 

func (c *DrawIndexedCommand) Execute(ctx *gl.Context)

type EnsureOffscreenFBOCommand added in v0.16.0 

type EnsureOffscreenFBOCommand struct {
	// contains filtered or unexported fields
}

EnsureOffscreenFBOCommand lazily creates a framebuffer object for an offscreen texture and binds it. If the texture already has an FBO, it simply binds it.

func (*EnsureOffscreenFBOCommand) Execute added in v0.16.0 

func (c *EnsureOffscreenFBOCommand) Execute(ctx *gl.Context)

type Fence 

type Fence struct {
	// contains filtered or unexported fields
}

Fence implements hal.Fence using GL sync objects.

func NewFence 

func NewFence(glCtx *gl.Context) *Fence

NewFence creates a new fence.

func (*Fence) Destroy 

func (f *Fence) Destroy()

Destroy releases fence resources.

func (*Fence) GetValue 

func (f *Fence) GetValue() uint64

GetValue returns the current fence value.

func (*Fence) Reset added in v0.13.0 

func (f *Fence) Reset()

Reset resets the fence to the unsignaled state.

func (*Fence) Signal 

func (f *Fence) Signal(value uint64)

Signal sets the fence value.

func (*Fence) Wait 

func (f *Fence) Wait(value uint64, _ time.Duration) bool

Wait waits for the fence to reach the specified value.

type Instance 

type Instance struct{}

Instance implements hal.Instance for the OpenGL backend on Linux.

func (*Instance) CreateSurface 

func (i *Instance) CreateSurface(displayHandle, windowHandle uintptr) (hal.Surface, error)

CreateSurface creates an OpenGL surface from window handles. On Linux: displayHandle and windowHandle are platform-specific. For X11: displayHandle is X11 Display*, windowHandle is Window. For Wayland: displayHandle is wl_display*, windowHandle is wl_surface*.

func (*Instance) Destroy 

func (i *Instance) Destroy()

Destroy releases the instance resources.

func (*Instance) EnumerateAdapters 

func (i *Instance) EnumerateAdapters(surfaceHint hal.Surface) []hal.ExposedAdapter

EnumerateAdapters returns available OpenGL adapters. For OpenGL, there's typically one adapter per display.

type MSAAResolveCommand added in v0.16.0 

type MSAAResolveCommand struct {
	// contains filtered or unexported fields
}

MSAAResolveCommand resolves an MSAA framebuffer to a single-sample framebuffer using glBlitFramebuffer. This is recorded at render pass End() when a ResolveTarget is specified in the color attachment.

When resolveToSurface is true, the destination is the Surface's swapchain offscreen FBO (NOT FBO 0). No Y-flip is applied here — the Y-flip is the sole responsibility of Queue.Present, which blits the swapchain FBO to FBO 0 with srcY0=height, srcY1=0 before SwapBuffers. Mirrors Rust wgpu-hal: MSAA resolve lands in an offscreen target, present blit un-flips.

func (*MSAAResolveCommand) Execute added in v0.16.0 

func (c *MSAAResolveCommand) Execute(ctx *gl.Context)

type PipelineLayout 

type PipelineLayout struct {
	// contains filtered or unexported fields
}

PipelineLayout implements hal.PipelineLayout for OpenGL. Stores pre-computed per-type sequential binding indices (Rust wgpu pattern). The BindingMap is used by naga GLSL writer, GroupInfos by SetBindGroup at runtime.

func (*PipelineLayout) Destroy 

func (l *PipelineLayout) Destroy()

Destroy is a no-op for pipeline layouts.

type PipelineLayoutDescriptor 

type PipelineLayoutDescriptor = hal.PipelineLayoutDescriptor

Type aliases for hal descriptors

type Queue 

type Queue struct {
	// contains filtered or unexported fields
}

Queue implements hal.Queue for OpenGL on Linux.

func (*Queue) GetTimestampPeriod 

func (q *Queue) GetTimestampPeriod() float32

GetTimestampPeriod returns the timestamp period in nanoseconds.

func (*Queue) PollCompleted added in v0.23.0 

func (q *Queue) PollCompleted() uint64

PollCompleted returns the highest submission index known to be completed. GLES is synchronous — after Flush, all submitted work is complete.

func (*Queue) Present 

func (q *Queue) Present(surface hal.Surface, _ hal.SurfaceTexture, damageRects []image.Rectangle) error

Present presents a surface texture to the screen.

Before SwapBuffers, blits the Surface's swapchain offscreen FBO to the default framebuffer (FBO 0) with an explicit Y-flip. User render passes render upside-down into the swapchain FBO (driven by naga's in-shader Y-flip); the blit un-flips for presentation. Mirrors Rust wgpu-hal src/gles/egl.rs Surface::present (1280-1308).

damageRects is an optional list of rectangles (physical pixels, top-left origin) indicating which surface regions changed this frame. When non-empty and EGL_KHR_swap_buffers_with_damage is available, the rects are passed to eglSwapBuffersWithDamageKHR as compositor hints. EGL uses bottom-left origin, so Y coordinates are flipped here. When the extension is unavailable or no rects are provided, the standard eglSwapBuffers path is used.

func (*Queue) Submit 

func (q *Queue) Submit(commandBuffers []hal.CommandBuffer) (uint64, error)

Submit submits command buffers to the GPU. GLES is synchronous, so the submission is effectively complete immediately after Flush.

func (*Queue) SupportsCommandBufferCopies added in v0.23.4 

func (q *Queue) SupportsCommandBufferCopies() bool

SupportsCommandBufferCopies returns false for GLES on Linux. GLES uses direct GL calls for writes, not command buffer copy operations.

func (*Queue) WriteBuffer 

func (q *Queue) WriteBuffer(buffer hal.Buffer, offset uint64, data []byte) error

WriteBuffer writes data to a buffer immediately.

func (*Queue) WriteTexture 

func (q *Queue) WriteTexture(dst *hal.ImageCopyTexture, data []byte, layout *hal.ImageDataLayout, size *hal.Extent3D) error

WriteTexture writes data to a texture immediately.

type RenderPassEncoder 

type RenderPassEncoder struct {
	// contains filtered or unexported fields
}

RenderPassEncoder implements hal.RenderPassEncoder for OpenGL.

func (*RenderPassEncoder) Draw 

func (e *RenderPassEncoder) Draw(vertexCount, instanceCount, firstVertex, firstInstance uint32)

Draw draws primitives.

func (*RenderPassEncoder) DrawIndexed 

func (e *RenderPassEncoder) DrawIndexed(indexCount, instanceCount, firstIndex uint32, baseVertex int32, firstInstance uint32)

DrawIndexed draws indexed primitives.

func (*RenderPassEncoder) DrawIndexedIndirect 

func (e *RenderPassEncoder) DrawIndexedIndirect(buffer hal.Buffer, offset uint64)

DrawIndexedIndirect draws indexed primitives with GPU-generated parameters. Note: Requires GL_ARB_draw_indirect (GL 4.0+ / GLES 3.1+). Currently not implemented - use direct DrawIndexed calls instead.

func (*RenderPassEncoder) DrawIndirect 

func (e *RenderPassEncoder) DrawIndirect(buffer hal.Buffer, offset uint64)

DrawIndirect draws primitives with GPU-generated parameters. Note: Requires GL_ARB_draw_indirect (GL 4.0+ / GLES 3.1+). Currently not implemented - use direct Draw calls instead.

func (*RenderPassEncoder) End 

func (e *RenderPassEncoder) End()

End finishes the render pass. If MSAA resolve is needed, blits the MSAA FBO to the resolve target FBO. If the pass was rendering to an offscreen FBO, rebinds the default framebuffer so subsequent operations do not accidentally target the offscreen texture.

func (*RenderPassEncoder) ExecuteBundle 

func (e *RenderPassEncoder) ExecuteBundle(bundle hal.RenderBundle)

ExecuteBundle executes a pre-recorded render bundle. Note: Render bundles are not natively supported in OpenGL. OpenGL uses display lists (deprecated) or VAO/VBO state caching. This is a no-op - bundles are expanded inline in the command stream.

func (*RenderPassEncoder) SetBindGroup 

func (e *RenderPassEncoder) SetBindGroup(index uint32, group hal.BindGroup, offsets []uint32)

SetBindGroup sets a bind group.

func (*RenderPassEncoder) SetBlendConstant 

func (e *RenderPassEncoder) SetBlendConstant(color *gputypes.Color)

SetBlendConstant sets the blend constant.

func (*RenderPassEncoder) SetIndexBuffer 

func (e *RenderPassEncoder) SetIndexBuffer(buffer hal.Buffer, format gputypes.IndexFormat, offset uint64)

SetIndexBuffer sets the index buffer.

func (*RenderPassEncoder) SetPipeline 

func (e *RenderPassEncoder) SetPipeline(pipeline hal.RenderPipeline)

SetPipeline sets the render pipeline.

func (*RenderPassEncoder) SetScissorRect 

func (e *RenderPassEncoder) SetScissorRect(x, y, width, height uint32)

SetScissorRect sets the scissor rectangle. With ADJUST_COORDINATE_SPACE, no Y-flip is needed — coordinates pass through directly.

func (*RenderPassEncoder) SetStencilReference 

func (e *RenderPassEncoder) SetStencilReference(ref uint32)

SetStencilReference sets the stencil reference value.

func (*RenderPassEncoder) SetVertexBuffer 

func (e *RenderPassEncoder) SetVertexBuffer(slot uint32, buffer hal.Buffer, offset uint64)

SetVertexBuffer sets a vertex buffer and configures vertex attributes. In OpenGL, vertex attribute configuration (glVertexAttribPointer + glEnableVertexAttribArray) must be done explicitly. The layout is taken from the currently bound render pipeline's vertex buffer descriptors.

func (*RenderPassEncoder) SetViewport 

func (e *RenderPassEncoder) SetViewport(x, y, width, height, minDepth, maxDepth float32)

SetViewport sets the viewport.

type RenderPipeline 

type RenderPipeline struct {
	// contains filtered or unexported fields
}

RenderPipeline implements hal.RenderPipeline for OpenGL.

func (*RenderPipeline) Destroy 

func (p *RenderPipeline) Destroy()

Destroy releases the render pipeline.

type RenderPipelineDescriptor 

type RenderPipelineDescriptor = hal.RenderPipelineDescriptor

Type aliases for hal descriptors

type Sampler 

type Sampler struct {
	// contains filtered or unexported fields
}

Sampler implements hal.Sampler for OpenGL using GL sampler objects (GL 3.3+).

func (*Sampler) Destroy 

func (s *Sampler) Destroy()

Destroy releases the GL sampler object.

func (*Sampler) NativeHandle added in v0.12.0 

func (s *Sampler) NativeHandle() uintptr

NativeHandle returns the GL sampler object ID.

type SamplerDescriptor 

type SamplerDescriptor = hal.SamplerDescriptor

Type aliases for hal descriptors

type SetBindGroupCommand 

type SetBindGroupCommand struct {
	// contains filtered or unexported fields
}

SetBindGroupCommand binds resources.

func (*SetBindGroupCommand) Execute 

func (c *SetBindGroupCommand) Execute(ctx *gl.Context)

type SetBlendConstantCommand 

type SetBlendConstantCommand struct {
	// contains filtered or unexported fields
}

SetBlendConstantCommand sets blend constant.

func (*SetBlendConstantCommand) Execute 

func (c *SetBlendConstantCommand) Execute(ctx *gl.Context)

type SetIndexBufferCommand 

type SetIndexBufferCommand struct {
	// contains filtered or unexported fields
}

SetIndexBufferCommand binds an index buffer.

func (*SetIndexBufferCommand) Execute 

func (c *SetIndexBufferCommand) Execute(ctx *gl.Context)

type SetPipelineStateCommand 

type SetPipelineStateCommand struct {
	// contains filtered or unexported fields
}

SetPipelineStateCommand sets pipeline state (culling, depth, stencil, blending, color mask).

func (*SetPipelineStateCommand) Execute 

func (c *SetPipelineStateCommand) Execute(ctx *gl.Context)

type SetScissorCommand 

type SetScissorCommand struct {
	// contains filtered or unexported fields
}

SetScissorCommand sets the scissor rectangle. With ADJUST_COORDINATE_SPACE enabled, the scene is rendered upside-down in GL. The scissor coordinates are passed through directly (no Y-flip needed) because the scissor operates in the same flipped coordinate space as the rendered content. This matches Rust wgpu-hal GLES which also passes scissor through without Y-flip.

func (*SetScissorCommand) Execute 

func (c *SetScissorCommand) Execute(ctx *gl.Context)

type SetStencilRefCommand 

type SetStencilRefCommand struct {
	// contains filtered or unexported fields
}

SetStencilRefCommand updates the stencil reference value. This re-applies glStencilFuncSeparate with the new reference while keeping the compare function and read mask from the current pipeline.

func (*SetStencilRefCommand) Execute 

func (c *SetStencilRefCommand) Execute(ctx *gl.Context)

type SetVertexBufferCommand 

type SetVertexBufferCommand struct {
	// contains filtered or unexported fields
}

SetVertexBufferCommand binds a vertex buffer and configures vertex attributes. In OpenGL, vertex attributes must be configured explicitly via glVertexAttribPointer + glEnableVertexAttribArray. The layout describes how vertex data is interpreted (attribute locations, formats, strides).

func (*SetVertexBufferCommand) Execute 

func (c *SetVertexBufferCommand) Execute(ctx *gl.Context)

type SetViewportCommand 

type SetViewportCommand struct {
	// contains filtered or unexported fields
}

SetViewportCommand sets the viewport.

func (*SetViewportCommand) Execute 

func (c *SetViewportCommand) Execute(ctx *gl.Context)

type ShaderModule 

type ShaderModule struct {
	// contains filtered or unexported fields
}

ShaderModule implements hal.ShaderModule for OpenGL.

func (*ShaderModule) Destroy 

func (m *ShaderModule) Destroy()

Destroy releases the shader module.

type ShaderModuleDescriptor 

type ShaderModuleDescriptor = hal.ShaderModuleDescriptor

Type aliases for hal descriptors

type Surface 

type Surface struct {
	// contains filtered or unexported fields
}

Surface implements hal.Surface for OpenGL on Linux.

func (*Surface) AcquireTexture 

func (s *Surface) AcquireTexture(_ hal.Fence) (*hal.AcquiredSurfaceTexture, error)

AcquireTexture returns the next surface texture for rendering.

func (*Surface) Configure 

func (s *Surface) Configure(_ hal.Device, config *hal.SurfaceConfiguration) error

Configure configures the surface for presentation.

Returns hal.ErrZeroArea if width or height is zero. This commonly happens when the window is minimized or not yet fully visible. Wait until the window has valid dimensions before calling Configure again.

func (*Surface) Destroy 

func (s *Surface) Destroy()

Destroy releases the surface resources.

func (*Surface) DiscardTexture 

func (s *Surface) DiscardTexture(_ hal.SurfaceTexture)

DiscardTexture discards a previously acquired texture.

func (*Surface) GetAdapterInfo 

func (s *Surface) GetAdapterInfo() hal.ExposedAdapter

GetAdapterInfo returns adapter information from this surface's GL context.

func (*Surface) Unconfigure 

func (s *Surface) Unconfigure(_ hal.Device)

Unconfigure marks the surface as unconfigured.

type SurfaceTexture 

type SurfaceTexture struct {
	// contains filtered or unexported fields
}

SurfaceTexture implements hal.SurfaceTexture for OpenGL. It represents the default framebuffer.

func (*SurfaceTexture) AddPendingRef added in v0.23.4 

func (t *SurfaceTexture) AddPendingRef()

func (*SurfaceTexture) CurrentUsage added in v0.23.4 

func (t *SurfaceTexture) CurrentUsage() gputypes.TextureUsage

CurrentUsage returns 0 — GLES surface textures have no state tracking.

func (*SurfaceTexture) DecPendingRef added in v0.23.4 

func (t *SurfaceTexture) DecPendingRef()

func (*SurfaceTexture) Destroy 

func (t *SurfaceTexture) Destroy()

Destroy is a no-op for surface textures.

func (*SurfaceTexture) NativeHandle added in v0.12.0 

func (t *SurfaceTexture) NativeHandle() uintptr

NativeHandle returns 0 (OpenGL default framebuffer has no handle).

type Texture 

type Texture struct {
	// contains filtered or unexported fields
}

Texture implements hal.Texture for OpenGL.

func (*Texture) AddPendingRef added in v0.23.4 

func (t *Texture) AddPendingRef()

func (*Texture) CurrentUsage added in v0.23.4 

func (t *Texture) CurrentUsage() gputypes.TextureUsage

CurrentUsage returns 0 — GLES has no explicit resource state tracking.

func (*Texture) DecPendingRef added in v0.23.4 

func (t *Texture) DecPendingRef()

func (*Texture) Destroy 

func (t *Texture) Destroy()

Destroy releases the texture and any associated framebuffer object.

func (*Texture) NativeHandle added in v0.12.0 

func (t *Texture) NativeHandle() uintptr

NativeHandle returns the GL texture object ID.

type TextureDescriptor 

type TextureDescriptor = hal.TextureDescriptor

Type aliases for hal descriptors

type TextureView 

type TextureView struct {
	// contains filtered or unexported fields
}

TextureView implements hal.TextureView for OpenGL.

func (*TextureView) Destroy 

func (v *TextureView) Destroy()

Destroy is a no-op for texture views in OpenGL.

func (*TextureView) NativeHandle added in v0.12.0 

func (v *TextureView) NativeHandle() uintptr

NativeHandle returns the underlying texture's GL object ID.

type TextureViewDescriptor 

type TextureViewDescriptor = hal.TextureViewDescriptor

Type aliases for hal descriptors

type UseProgramCommand 

type UseProgramCommand struct {
	// contains filtered or unexported fields
}

UseProgramCommand activates a shader program.

func (*UseProgramCommand) Execute 

func (c *UseProgramCommand) Execute(ctx *gl.Context)

Source Files

View all Source files

Directories

Path Synopsis
Package egl provides EGL (EGL) context management for OpenGL ES on Linux.
 Package egl provides EGL (EGL) context management for OpenGL ES on Linux.
Package gl provides OpenGL constants and types for the GLES backend.
 Package gl provides OpenGL constants and types for the GLES backend.
Package wgl provides Windows OpenGL (WGL) context management.
 Package wgl provides Windows OpenGL (WGL) context management.

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