graphicscommand

Documentation

Overview

Package graphicscommand represents a low layer for graphics using OpenGL.

Index

• Constants
• func DumpImages(images []*Image, graphicsDriver graphicsdriver.Graphics, dir string) (string, error)
• func FlushCommands(graphicsDriver graphicsdriver.Graphics, endFrame bool, swapBuffersForGL func()) error
• func InitializeGraphicsDriverState(graphicsDriver graphicsdriver.Graphics) (err error)
• func LogImagesInfo(images []*Image)
• func MaxImageSize(graphicsDriver graphicsdriver.Graphics) int
• func ResetGraphicsDriverState(graphicsDriver graphicsdriver.Graphics) (err error)
• func SetRenderThread(thread thread.Thread)
• func SetVsyncEnabled(enabled bool)
• type Image
  • func NewImage(width, height int, screenFramebuffer bool) *Image
  • func (i *Image) Dispose()
  • func (i *Image) DrawTriangles(srcs [graphics.ShaderImageCount]*Image, vertices []float32, indices []uint32, ...)
  • func (i *Image) Dump(graphicsDriver graphicsdriver.Graphics, path string, blackbg bool, ...) (string, error)
  • func (i *Image) InternalSize() (int, int)
  • func (i *Image) IsInvalidated(graphicsDriver graphicsdriver.Graphics) (bool, error)
  • func (i *Image) ReadPixels(graphicsDriver graphicsdriver.Graphics, args []graphicsdriver.PixelsArgs) error
  • func (i *Image) WritePixels(pixels *graphics.ManagedBytes, region image.Rectangle)
• type Shader
  • func NewShader(ir *shaderir.Program) *Shader
  • func (s *Shader) Dispose()

Constants

const (

	// MaxVertexCount is the maximum number of vertices for one draw call.
	//
	// On 64bit architectures, this value is 2^32-1, as the index type is uint32.
	// This value cannot be exactly 2^32 especially with WebGL 2, as 2^32th vertex is not rendered correctly.
	// See https://registry.khronos.org/webgl/specs/latest/2.0/#5.18 .
	//
	// On 32bit architectures, this value is an adjusted number so that maxVertexFloatCount doesn't overflow int.
	MaxVertexCount = is64bit*math.MaxUint32 + is32bit*(math.MaxInt32/graphics.VertexFloatCount)
)

Functions

func DumpImages

func DumpImages(images []*Image, graphicsDriver graphicsdriver.Graphics, dir string) (string, error)

DumpImages dumps all the current images to the specified directory.

This is for testing usage.

func FlushCommands

func FlushCommands(graphicsDriver graphicsdriver.Graphics, endFrame bool, swapBuffersForGL func()) error

FlushCommands flushes the command queue and present the screen if needed. If endFrame is true, the current screen might be used to present.

func InitializeGraphicsDriverState

func InitializeGraphicsDriverState(graphicsDriver graphicsdriver.Graphics) (err error)

InitializeGraphicsDriverState initialize the current graphics driver state.

func LogImagesInfo

func LogImagesInfo(images []*Image)

func MaxImageSize

func MaxImageSize(graphicsDriver graphicsdriver.Graphics) int

MaxImageSize returns the maximum size of an image.

func ResetGraphicsDriverState

func ResetGraphicsDriverState(graphicsDriver graphicsdriver.Graphics) (err error)

ResetGraphicsDriverState resets the current graphics driver state. If the graphics driver doesn't have an API to reset, ResetGraphicsDriverState does nothing.

func SetRenderThread

func SetRenderThread(thread thread.Thread)

SetRenderThread must be called from the rendering thread where e.g. OpenGL works.

TODO: Create thread in this package instead of setting it externally.

func SetVsyncEnabled

func SetVsyncEnabled(enabled bool)

Types

type Image

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

Image represents an image that is implemented with OpenGL.

func NewImage

func NewImage(width, height int, screenFramebuffer bool) *Image

NewImage returns a new image.

Note that the image is not initialized yet.

func (*Image) Dispose

func (i *Image) Dispose()

func (*Image) DrawTriangles

func (i *Image) DrawTriangles(srcs [graphics.ShaderImageCount]*Image, vertices []float32, indices []uint32, blend graphicsdriver.Blend, dstRegion image.Rectangle, srcRegions [graphics.ShaderImageCount]image.Rectangle, shader *Shader, uniforms []uint32, fillRule graphicsdriver.FillRule)

DrawTriangles draws triangles with the given image.

The vertex floats are:

0: Destination X in pixels
1: Destination Y in pixels
2: Source X in texels
3: Source Y in texels
4: Color R [0.0-1.0]
5: Color G
6: Color B
7: Color Y

src and shader are exclusive and only either is non-nil.

The elements that index is in between 2 and 7 are used for the source images. The source image is 1) src argument if non-nil, or 2) an image value in the uniform variables if it exists. If there are multiple images in the uniform variables, the smallest ID's value is adopted.

If the source image is not specified, i.e., src is nil and there is no image in the uniform variables, the elements for the source image are not used.

func (*Image) Dump

func (i *Image) Dump(graphicsDriver graphicsdriver.Graphics, path string, blackbg bool, rect image.Rectangle) (string, error)

func (*Image) InternalSize

func (i *Image) InternalSize() (int, int)

func (*Image) IsInvalidated

func (i *Image) IsInvalidated(graphicsDriver graphicsdriver.Graphics) (bool, error)

func (*Image) ReadPixels

func (i *Image) ReadPixels(graphicsDriver graphicsdriver.Graphics, args []graphicsdriver.PixelsArgs) error

ReadPixels reads the image's pixels. ReadPixels returns an error when an error happens in the graphics driver.

func (*Image) WritePixels

func (i *Image) WritePixels(pixels *graphics.ManagedBytes, region image.Rectangle)

type Shader

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

func NewShader

func NewShader(ir *shaderir.Program) *Shader

func (*Shader) Dispose

func (s *Shader) Dispose()