gl

package module
v0.0.0-...-9720903 Latest Latest
Warning

This package is not in the latest version of its module.

 Go to latest Published: Jul 10, 2013 License: MIT Imports: 5 Imported by: 0

README 

OpenGL ES bindings for Go.

Documentation

Overview

Package gl provides a set of bindings for OpenGL ES.

The intent of this package is to provide a very simple one-to-one set of bindings, but with some small modification to be more Go-friendly, and to take advantage of some of the niceties available in Go (extra type safety, reflection, methods, color.Color, etc.). With very few exceptions, each function or method in this package corresponds directly to a single OpenGL ES function. The exceptions to this rule are noted explicitly in their documentation.

A Note on Naming

Enum names are the same as their corresponding name in C, but they are in CamlCase and have the "GL" prefix removed. For example: GL_COLOR_BUFFER_BIT is ColorBufferBit. In a very small number of cases the names needed an extra prefix to disambiguate constants of different types that would otherwise have the same name. For example, GL_DELETE_STATUS is both ShaderDeleteStatus or ProgramDeleteStatus. One can be used when getting properties from shaders, and the other when getting properties from programs. This provides better type safety and is not expected to lead to any confusion. Additionally, godoc should make it trivial to find the avaliable enum values for differenc functions since they are associated with parameters via their types.

Function names are the same as their corresponding name in C but with the "gl" prefix and all size and type suffixes removed. Functions whose C equivalents operate on objects (such as buffers, shaders, programs, textures, etc.) have been converted to methods.

Method names are the same as their corresponding function names in C but with the "gl" prefix, all size and type suffixes, and the object name removed where possible. In cases where these removals results in an empty identifier (e.g., glUniform) then the object name is not removed. For example: 

glShaderCompile is Shader.Compile
glGetProgram  is Program.Get
glEnableVertexAttribArray is VertexAttribArray.Enable()
glUniform is Uniform.Uniform

This should save typing in many places and be, overall, more pleasent.

It should be noted that these rules make for some non-idiomatic names. For example, getter methods have a "Get" prefix (Shader.GetInfoLog) and setter methods have no prefix (Shader.Source); Go prefers the opposite: no prefix for getters, and a "Set" prefix for setters. While annoying, this wasn't reconsiled on purpose. This package doesn't provide detailed documentation, and the ability to easily go between these names iand their C equivalents in order to find the documentation is more important than idioms (even if Go's idiom is superior ☺).

An apology

I must apologize in advance for the poor godoc comments. The comments for functions and methods are straight out of the man pages and are, in most cases, completely unhelpful. On the other hand, OpenGL is fairly complex, and I am in no way qualified to write useful documentation for it. I am also not qualified to write documentation geared toward those who have never used OpenGL before, so this package's documentation assumes a user who is familiar with OpenGL from other sources. I found this tutorial helpful: http://www.arcsynthesis.org/gltut.

Index

Constants

View Source 
const (
	Nearest = C.GL_NEAREST
	Linear  = C.GL_LINEAR
)

Variables

This section is empty.

Functions

func ActiveTexture 

func ActiveTexture(unit int)

ActiveTexture selects active texture unit. Unit must be between 0 and the maximum supported texture units, of which there are at least 80.

func BlendFunc 

func BlendFunc(srcFactor, dstFactor BlendFunction)

BlendFunc specifies pixel arithmetic

func BufferData 

func BufferData(targ BufferTarget, data interface{}, usage BufferDataUsage)

BufferData creates and initializes a buffer object's data store.

func BufferSubData 

func BufferSubData(targ BufferTarget, offs int, data interface{})

BufferSubData updates a subset of a buffer object's data store.

func Clear 

func Clear(bits ClearFlags)

Clear clears buffers to preset values.

func ClearColor 

func ClearColor(col color.Color)

ClearColor specifies clear values for the color buffers.

func ClearDepth 

func ClearDepth(d float32)

ClearDepth specifies the clear value for the depth buffer.

func ClearStencil 

func ClearStencil(s int)

ClearStencil specifies the clear value for the stencil buffer.

func DeleteBuffers 

func DeleteBuffers(bufs []Buffer)

DeleteBuffers deletes named buffer objects.

func DeleteTextures 

func DeleteTextures(texs []Texture)

DeleteTextures deletes named textures.

func Disable 

func Disable(c Capability)

Disable disables OpenGL capabilities.

func DrawArrays 

func DrawArrays(mode DrawMode, first, count int)

DrawArrays renders primitives from array data.

func Enable 

func Enable(c Capability)

Enable enables OpenGL capabilities.

func Finish 

func Finish()

Finish blocks until all GL execution is complete.

func Flush 

func Flush()

Flush forces execution of GL commands in finite time.

func GetError 

func GetError() error

GetError returns error information: an error if one occurred or nil.

func LineWidth 

func LineWidth(w float32)

LineWidth specifies the width of rasterized lines.

func TexImage2D 

func TexImage2D(targ TextureTarget, lvl int, ifmt TextureFormat, w, h, border int, fmt TextureFormat, data interface{})

TexImage2D specifies a two-dimensional texture image.

func TexParameter 

func TexParameter(targ TextureTarget, parm TexParam, val interface{})

TexParameter sets texture parameters.

Types

type BlendFunction 

type BlendFunction C.GLenum

BlendFunction specifies how either source or destination colors are blended. 

const (
	Zero                  BlendFunction = C.GL_ZERO
	One                   BlendFunction = C.GL_ONE
	SrcColor              BlendFunction = C.GL_SRC_COLOR
	OneMinusSrcColor      BlendFunction = C.GL_ONE_MINUS_SRC_COLOR
	SrcAlpha              BlendFunction = C.GL_SRC_ALPHA
	OneMinusSrcAlpha      BlendFunction = C.GL_ONE_MINUS_SRC_ALPHA
	DstColor              BlendFunction = C.GL_DST_COLOR
	OneMinusDstColor      BlendFunction = C.GL_ONE_MINUS_DST_COLOR
	DstAlpha              BlendFunction = C.GL_DST_ALPHA
	OneMinusDstAlpha      BlendFunction = C.GL_ONE_MINUS_DST_ALPHA
	ConstantColor         BlendFunction = C.GL_CONSTANT_COLOR
	OneMinusConstantColor BlendFunction = C.GL_ONE_MINUS_CONSTANT_COLOR
	ConstantAlpha         BlendFunction = C.GL_CONSTANT_ALPHA
	OneMinusConstantAlpha BlendFunction = C.GL_ONE_MINUS_CONSTANT_ALPHA
)

type Buffer 

type Buffer C.GLuint

A Buffer is an OpenGL buffer object.

func GenBuffers 

func GenBuffers(n int) []Buffer

GenBuffers generates and returns n named buffer objects.

func (Buffer) Bind 

func (b Buffer) Bind(targ BufferTarget)

Bind binds a named buffer object.

func (Buffer) Delete 

func (b Buffer) Delete()

Delete deletes the named buffer object.

type BufferDataUsage 

type BufferDataUsage C.GLenum
const (
	StaticDraw  BufferDataUsage = C.GL_STATIC_DRAW
	StreamDraw  BufferDataUsage = C.GL_STREAM_DRAW
	DynamicDraw BufferDataUsage = C.GL_DYNAMIC_DRAW
)

type BufferTarget 

type BufferTarget C.GLenum
const (
	ArrayBuffer        BufferTarget = C.GL_ARRAY_BUFFER
	ElementArrayBuffer BufferTarget = C.GL_ELEMENT_ARRAY_BUFFER
)

type Capability 

type Capability C.GLenum

A Capability is a feature of OpenGL that can be enabled or disabled. 

const (
	Blend  Capability = C.GL_BLEND
	Dither Capability = C.GL_DITHER
)

type ClearFlags 

type ClearFlags C.GLbitfield

ClearFlags is a bitset type for the flags to Clear. 

const (
	ColorBufferBit   ClearFlags = C.GL_COLOR_BUFFER_BIT
	DepthBufferBit   ClearFlags = C.GL_DEPTH_BUFFER_BIT
	StencilBufferBit ClearFlags = C.GL_STENCIL_BUFFER_BIT
)

type DataType 

type DataType C.GLenum

A DataType defines the type of data elements. 

const (
	Float         DataType = C.GL_FLOAT
	Byte          DataType = C.GL_BYTE
	Short         DataType = C.GL_SHORT
	UnsignedByte  DataType = C.GL_UNSIGNED_BYTE
	UnsignedShort DataType = C.GL_UNSIGNED_SHORT
)

type DrawMode 

type DrawMode C.GLenum

DrawMode specifies what to draw. 

const (
	Points        DrawMode = C.GL_POINTS
	LineStrip     DrawMode = C.GL_LINE_STRIP
	LineLoop      DrawMode = C.GL_LINE_LOOP
	Lines         DrawMode = C.GL_LINES
	TriangleStrip DrawMode = C.GL_TRIANGLE_STRIP
	TriangleFan   DrawMode = C.GL_TRIANGLE_FAN
	Triangles     DrawMode = C.GL_TRIANGLES
)

type Program 

type Program C.GLuint

A Program is a set of linked shaders that can be loaded onto the graphics card.

func CreateProgram 

func CreateProgram() Program

CreateProgram creates a program object.

func (Program) AttachShader 

func (p Program) AttachShader(s Shader)

AttachShader attaches a shader object to a program object.

func (Program) Delete 

func (p Program) Delete()

Delete deletes a program object.

func (Program) DetachShader 

func (p Program) DetachShader(s Shader)

DetachShader detaches a shader object from a program object to which it is attached.

func (Program) Get 

func (p Program) Get(parm ProgramParameter) int

Get returns a parameter from a program object.

func (Program) GetAttribLocation 

func (p Program) GetAttribLocation(name string) VertexAttribArray

GetAttribLocation returns the location of an attribute variable.

func (Program) GetInfoLog 

func (p Program) GetInfoLog() string

GetInfoLog returns the information log for a program object. This method makes two OpenGL calls: one to get the info log size, and one to get the info log.

func (Program) GetUniformLocation 

func (p Program) GetUniformLocation(name string) Uniform

GetUniformLocation returns the location of a uniform variable. 

func (p Program) Link()

Link links a program object.

func (Program) Use 

func (p Program) Use()

Use installs a program object as part of current rendering state.

type ProgramParameter 

type ProgramParameter C.GLenum

A ProgramParameter is a gettable parameter of a program. 

const (
	ProgramDeleteStatus      ProgramParameter = C.GL_DELETE_STATUS
	LinkStatus               ProgramParameter = C.GL_LINK_STATUS
	ValidateStatus           ProgramParameter = C.GL_VALIDATE_STATUS
	ProgramInfoLogLength     ProgramParameter = C.GL_INFO_LOG_LENGTH
	AttachedShaders          ProgramParameter = C.GL_ATTACHED_SHADERS
	ActiveAttributes         ProgramParameter = C.GL_ACTIVE_ATTRIBUTES
	ActiveAttributeMaxLength ProgramParameter = C.GL_ACTIVE_ATTRIBUTE_MAX_LENGTH
	ActiveUniforms           ProgramParameter = C.GL_ACTIVE_UNIFORMS
	ActiveUniformMaxLength   ProgramParameter = C.GL_ACTIVE_UNIFORM_MAX_LENGTH
)

type Shader 

type Shader C.GLuint

func CreateShader 

func CreateShader(kind ShaderKind) Shader

CreateShader creates a shader object.

func (Shader) Compile 

func (s Shader) Compile()

Compile compiles a shader object.

func (Shader) Delete 

func (s Shader) Delete()

Delete deletes a shader.

func (Shader) Get 

func (s Shader) Get(parm ShaderParameter) int

Get returns a parameter from a shader object

func (Shader) GetInfoLog 

func (s Shader) GetInfoLog() string

GetInfoLog returns the information log for a shader object. This method makes two OpenGL calls: one to get the info log size, and one to get the info log.

func (Shader) Source 

func (s Shader) Source(src ...string)

Source replaces the source code in a shader object.

type ShaderKind 

type ShaderKind C.GLenum

A ShaderKind specifies the type of shader. 

const (
	VertexShader   ShaderKind = C.GL_VERTEX_SHADER
	FragmentShader ShaderKind = C.GL_FRAGMENT_SHADER
)

type ShaderParameter 

type ShaderParameter C.GLenum

A ShaderParameter names a gettable parameter of a shader. 

const (
	CompileStatus       ShaderParameter = C.GL_COMPILE_STATUS
	ShaderInfoLogLength ShaderParameter = C.GL_INFO_LOG_LENGTH
	ShaderSourceLength  ShaderParameter = C.GL_SHADER_SOURCE_LENGTH
	ShaderType          ShaderParameter = C.GL_SHADER_TYPE
	ShaderDeleteStatus  ShaderParameter = C.GL_DELETE_STATUS
)

type TexParam 

type TexParam C.GLenum

A TexParam is the name of a texture parameter. 

const (
	TextureMagFilter TexParam = C.GL_TEXTURE_MAG_FILTER
	TextureMinFilter TexParam = C.GL_TEXTURE_MIN_FILTER
)

type Texture 

type Texture C.GLuint

A Texture is the name of a texture object.

func GenTextures 

func GenTextures(n int) []Texture

GenTextures generates texture names.

func (Texture) Bind 

func (tex Texture) Bind(targ TextureTarget)

Bind binds a named texture to a texturing target.

func (Texture) Delete 

func (tex Texture) Delete()

Delete deletes a named texture.

type TextureFormat 

type TextureFormat C.GLenum

A TextureFormat specifies how to interpret texture data. 

const (
	Alpha          TextureFormat = C.GL_ALPHA
	Luminance      TextureFormat = C.GL_LUMINANCE
	LuminanceAlpha TextureFormat = C.GL_LUMINANCE_ALPHA
	RGB            TextureFormat = C.GL_RGB
	RGBA           TextureFormat = C.GL_RGBA
)

type TextureTarget 

type TextureTarget C.GLenum

A TextureTarget is a texturing target to which a texture can be bound. 

const (
	Texture2D TextureTarget = C.GL_TEXTURE_2D
)

type Uniform 

type Uniform C.GLint

func (Uniform) Uniform 

func (u Uniform) Uniform(vls ...interface{})

Uniform specifies the value of a uniform variable for the current program object.

type VertexAttribArray 

type VertexAttribArray C.GLuint

func (VertexAttribArray) Disable 

func (l VertexAttribArray) Disable()

Disable disables a generic vertex attribute array.

func (VertexAttribArray) Enable 

func (l VertexAttribArray) Enable()

Enable enables a generic vertex attribute array.

func (VertexAttribArray) Pointer 

func (l VertexAttribArray) Pointer(sz int, t DataType, norm bool, stride, offs int)

Pointer defines an array of generic vertex attribute data.

Source Files

View all Source files

Jump to

Keyboard shortcuts

? : This menu
/ : Search site
f or F : Jump to
y or Y : Canonical URL
go.dev uses cookies from Google to deliver and enhance the quality of its services and to analyze traffic. Learn more.