Golang gl.Str函数代码示例

// New creates a new shader object. The shader can later be activated by the given name with the Use function
func New(name, vertexShaderSource, fragmentShaderSource string) error {
	if _, found := shaderList[name]; found {
		return fmt.Errorf("Shader already exists: %v", name)
	}
	program, err := newProgram(vertexShaderSource, fragmentShaderSource)
	if err != nil {
		return err
	}
	shader := Shader{}
	shader.id = program
	shader.loaded = true
	shader.vert = vertexShaderSource
	shader.frag = fragmentShaderSource

	gl.UseProgram(shader.id)

	shader.Projection = gl.GetUniformLocation(program, gl.Str("projection\x00"))
	shader.Camera = gl.GetUniformLocation(program, gl.Str("camera\x00"))
	shader.Model = gl.GetUniformLocation(program, gl.Str("model\x00"))

	shaderList[name] = shader

	if activeShader := GetActive(); activeShader != nil {
		activeShader.Activate()
	}
	return nil
}

func (self *ShaderInfo) CompileShader() (uint32, error) {
	content, err := ioutil.ReadFile(self.Path)
	if err != nil {
		return 0, err
	}
	contentString := bytes.NewBuffer(content).String()
	glContentString := gl.Str(contentString + "\x00")

	shader := gl.CreateShader(self.ShaderType)
	gl.ShaderSource(shader, 1, &glContentString, nil)
	gl.CompileShader(shader)

	var status int32
	gl.GetShaderiv(shader, gl.COMPILE_STATUS, &status)
	if status == gl.FALSE {
		var logLength int32
		gl.GetShaderiv(shader, gl.INFO_LOG_LENGTH, &logLength)
		log := strings.Repeat("\x00", int(logLength+1))
		gl.GetShaderInfoLog(shader, logLength, nil, gl.Str(log))

		return 0, fmt.Errorf("failed to compile %v: %v", contentString, log)
	}

	return shader, nil
}

func newProgram(vertexShaderSource, fragmentShaderSource string) (uint32, error) {
	vertexShader, err := compileShader(vertexShaderSource, gl.VERTEX_SHADER)
	if err != nil {
		return 0, err
	}

	fragmentShader, err := compileShader(fragmentShaderSource, gl.FRAGMENT_SHADER)
	if err != nil {
		return 0, err
	}

	program := gl.CreateProgram()

	gl.AttachShader(program, vertexShader)
	gl.AttachShader(program, fragmentShader)
	gl.LinkProgram(program)

	var status int32
	gl.GetProgramiv(program, gl.LINK_STATUS, &status)
	if status == gl.FALSE {
		var logLength int32
		gl.GetProgramiv(program, gl.INFO_LOG_LENGTH, &logLength)

		log := strings.Repeat("\x00", int(logLength+1))
		gl.GetProgramInfoLog(program, logLength, nil, gl.Str(log))

		return 0, fmt.Errorf("failed to link program: %v", log)
	}

	gl.DeleteShader(vertexShader)
	gl.DeleteShader(fragmentShader)

	return program, nil
}

func LoadShaders(shaders []ShaderInfo) (uint32, error) {
	program := gl.CreateProgram()

	for _, shaderInfo := range shaders {
		shader, err := shaderInfo.CompileShader()
		if err != nil {
			return 0, err
		}
		gl.AttachShader(program, shader)
		gl.DeleteShader(shader)
	}

	gl.LinkProgram(program)

	var status int32
	gl.GetProgramiv(program, gl.LINK_STATUS, &status)
	if status == gl.FALSE {
		var logLength int32
		gl.GetProgramiv(program, gl.INFO_LOG_LENGTH, &logLength)

		log := strings.Repeat("\x00", int(logLength+1))
		gl.GetProgramInfoLog(program, logLength, nil, gl.Str(log))

		return 0, fmt.Errorf("Failed to link program: %v", log)
	}

	return program, nil
}

func setupUniforms(shader *renderer.Shader) {
	for name, uniform := range shader.Uniforms {
		uniformLocation := gl.GetUniformLocation(shader.Program, gl.Str(name+"\x00"))
		switch t := uniform.(type) {
		case bool:
			if t {
				gl.Uniform1i(uniformLocation, 1)
			} else {
				gl.Uniform1i(uniformLocation, 0)
			}
		case float32:
			gl.Uniform1f(uniformLocation, t)
		case float64:
			gl.Uniform1f(uniformLocation, float32(t))
		case int32:
			gl.Uniform1i(uniformLocation, t)
		case int:
			gl.Uniform1i(uniformLocation, int32(t))
		case mgl32.Vec2:
			gl.Uniform2f(uniformLocation, t[0], t[1])
		case mgl32.Vec3:
			gl.Uniform3f(uniformLocation, t[0], t[1], t[2])
		case mgl32.Vec4:
			gl.Uniform4f(uniformLocation, t[0], t[1], t[2], t[3])
		case mgl32.Mat4:
			gl.UniformMatrix4fv(uniformLocation, 1, false, &t[0])
		case []float32:
			gl.Uniform4fv(uniformLocation, (int32)(len(t)), &t[0])
		case []int32:
			gl.Uniform4iv(uniformLocation, (int32)(len(t)), &t[0])
		default:
			fmt.Printf("unexpected type for shader uniform: %T\n", t)
		}
	}
}

func newProgram(shaders ...uint32) (uint32, error) {
	program := gl.CreateProgram()

	for _, shader := range shaders {
		gl.AttachShader(program, shader)
	}
	gl.LinkProgram(program)

	var status int32
	gl.GetProgramiv(program, gl.LINK_STATUS, &status)
	if status == gl.FALSE {
		var logLength int32
		gl.GetProgramiv(program, gl.INFO_LOG_LENGTH, &logLength)

		log := strings.Repeat("\x00", int(logLength+1))
		gl.GetProgramInfoLog(program, logLength, nil, gl.Str(log))

		return 0, errors.New(fmt.Sprintf("failed to link program: %v", log))
	}

	for _, shader := range shaders {
		gl.DeleteShader(shader)
	}

	return program, nil
}

func compileShader(shaderCode string, shaderType uint32) uint32 {
	shader := gl.CreateShader(shaderType)
	shaderChars := gl.Str(shaderCode + "\x00")
	gl.ShaderSource(shader, 1, &shaderChars, nil)
	gl.CompileShader(shader)
	checkShaderCompileErrors(shader)
	return shader
}

func (c *Camera) Draw(program uint32) {
	//c.UpdateCamera()

	camera := mgl32.LookAtV(c.position, c.position.Add(c.direction), c.up)
	cameraUniform := gl.GetUniformLocation(program, gl.Str("camera\x00"))
	gl.UniformMatrix4fv(cameraUniform, 1, false, &camera[0])

}

func compileShaders() []uint32 {

	// create the vertex shader
	vertexShader := gl.CreateShader(gl.VERTEX_SHADER)
	shaderSourceChars := gl.Str(vertexShaderSource + "\x00")
	gl.ShaderSource(vertexShader, 1, &shaderSourceChars, nil)
	gl.CompileShader(vertexShader)
	checkShaderCompileErrors(vertexShader)

	// create the fragment shader
	fragmentShader := gl.CreateShader(gl.FRAGMENT_SHADER)
	shaderSourceChars = gl.Str(fragmentShaderSource + "\x00")
	gl.ShaderSource(fragmentShader, 1, &shaderSourceChars, nil)
	gl.CompileShader(fragmentShader)
	checkShaderCompileErrors(fragmentShader)

	return []uint32{vertexShader, fragmentShader}
}

// Load loads and sets up the model
func (m *Model) Load(fileName string) {

	m.loadFile(fileName)

	shader := sm.Shader{VertSrcFile: m.data.VertShaderFile, FragSrcFile: m.data.FragShaderFile, Name: fmt.Sprintf("%s:%s", m.data.VertShaderFile, m.data.FragShaderFile)}
	program, err := m.shaders.LoadProgram(shader, false)
	if err != nil {
		return
	}
	m.currentProgram = program

	gl.UseProgram(m.currentProgram)

	m.projection = mgl32.Perspective(mgl32.DegToRad(45.0), float32(windowWidth)/windowHeight, 0.1, 10.0)
	m.projectionUniform = gl.GetUniformLocation(m.currentProgram, gl.Str("projection\x00"))
	gl.UniformMatrix4fv(m.projectionUniform, 1, false, &m.projection[0])

	m.camera = mgl32.LookAtV(mgl32.Vec3{3, 3, 3}, mgl32.Vec3{0, 0, 0}, mgl32.Vec3{0, 1, 0})
	m.cameraUniform = gl.GetUniformLocation(m.currentProgram, gl.Str("camera\x00"))
	gl.UniformMatrix4fv(m.cameraUniform, 1, false, &m.camera[0])

	m.modelUniform = gl.GetUniformLocation(m.currentProgram, gl.Str("model\x00"))
	gl.UniformMatrix4fv(m.modelUniform, 1, false, &m.model[0])

	m.textureUniform = gl.GetUniformLocation(m.currentProgram, gl.Str("tex\x00"))
	gl.Uniform1i(m.textureUniform, 0)

	gl.BindFragDataLocation(m.currentProgram, 0, gl.Str("outputColor\x00"))

	// Load the texture
	m.textures.LoadTexture(m.data.TextureFile, m.data.TextureFile)

	// Configure the vertex data
	gl.GenVertexArrays(1, &m.vao)
	gl.BindVertexArray(m.vao)

	var vbo uint32
	gl.GenBuffers(1, &vbo)
	gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
	gl.BufferData(gl.ARRAY_BUFFER, len(m.data.Verts)*4, gl.Ptr(m.data.Verts), gl.STATIC_DRAW)

	vertAttrib := uint32(gl.GetAttribLocation(m.currentProgram, gl.Str("vert\x00")))
	gl.EnableVertexAttribArray(vertAttrib)
	gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, m.data.VertSize*4, gl.PtrOffset(0)) // 4:number of bytes in a float32

	texCoordAttrib := uint32(gl.GetAttribLocation(m.currentProgram, gl.Str("vertTexCoord\x00")))
	gl.EnableVertexAttribArray(texCoordAttrib)
	gl.VertexAttribPointer(texCoordAttrib, 2, gl.FLOAT, true, m.data.VertSize*4, gl.PtrOffset(3*4)) // 4:number of bytes in a float32

	if m.data.Indexed {
		var indices uint32
		gl.GenBuffers(1, &indices)
		gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, indices)
		gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(m.data.Indices)*4, gl.Ptr(m.data.Indices), gl.STATIC_DRAW)
	}

	gl.BindVertexArray(0)
}

func (glRenderer *OpenglRenderer) renderPostEffect(pe postEffect) {
	gl.UseProgram(pe.program)
	gl.ActiveTexture(gl.TEXTURE0)
	gl.BindTexture(gl.TEXTURE_2D, pe.textureId)
	gl.Disable(gl.CULL_FACE)
	gl.BindBuffer(gl.ARRAY_BUFFER, glRenderer.postEffectVbo)

	setupUniforms(pe.shader)

	vertAttrib := uint32(gl.GetAttribLocation(pe.program, gl.Str("vert\x00")))
	gl.EnableVertexAttribArray(vertAttrib)
	gl.VertexAttribPointer(vertAttrib, 2, gl.FLOAT, false, 4*4, gl.PtrOffset(0))
	texCoordAttrib := uint32(gl.GetAttribLocation(pe.program, gl.Str("vertTexCoord\x00")))
	gl.EnableVertexAttribArray(texCoordAttrib)
	gl.VertexAttribPointer(texCoordAttrib, 2, gl.FLOAT, false, 4*4, gl.PtrOffset(2*4))

	gl.DrawArrays(gl.TRIANGLE_STRIP, 0, 4)
	gl.DisableVertexAttribArray(texCoordAttrib)
}

func createProgram() uint32 {
	vs := gl.CreateShader(gl.VERTEX_SHADER)
	cvertexShader := gl.Str(vertexShader)
	gl.ShaderSource(vs, 1, &cvertexShader, nil)
	gl.CompileShader(vs)

	fs := gl.CreateShader(gl.FRAGMENT_SHADER)
	cfragmentShader := gl.Str(fragmentShader)
	gl.ShaderSource(fs, 1, &cfragmentShader, nil)
	gl.CompileShader(fs)

	shaderProgram := gl.CreateProgram()
	gl.AttachShader(shaderProgram, fs)
	gl.AttachShader(shaderProgram, vs)

	gl.LinkProgram(shaderProgram)

	return shaderProgram
}

func (me *Core) AddProgram(vertFile, fragFile string) int {
	vertexShader := gl.Str(readWholeFile(vertFile) + "\x00")
	fragmentShader := gl.Str(readWholeFile(fragFile) + "\x00")

	n := me.nbProg
	vs := gl.CreateShader(gl.VERTEX_SHADER)
	gl.ShaderSource(vs, 1, &vertexShader, nil)
	gl.CompileShader(vs)
	fs := gl.CreateShader(gl.FRAGMENT_SHADER)
	gl.ShaderSource(fs, 1, &fragmentShader, nil)
	gl.CompileShader(fs)

	me.Progs[n] = gl.CreateProgram()
	gl.AttachShader(me.Progs[n], fs)
	gl.AttachShader(me.Progs[n], vs)
	gl.LinkProgram(me.Progs[n])
	me.nbProg++
	return n
}

// Activate will draw everything with this program and load it if it isnt loaded.
func (shader *Shader) Activate() {
	if !shader.loaded {
		program, err := newProgram(shader.vert, shader.frag)
		if err != nil {
			panic(err)
		}
		shader.id = program
		shader.loaded = true

		gl.UseProgram(shader.id)

		shader.Projection = gl.GetUniformLocation(program, gl.Str("projection\x00"))
		shader.Camera = gl.GetUniformLocation(program, gl.Str("camera\x00"))
		shader.Model = gl.GetUniformLocation(program, gl.Str("model\x00"))

	}
	state.shader = shader
	gl.UseProgram(shader.id)
}

func compileShader(source string, shaderType uint32) (uint32, error) {
	shader := gl.CreateShader(shaderType)

	csource := gl.Str(source)
	gl.ShaderSource(shader, 1, &csource, nil)
	gl.CompileShader(shader)

	var status int32
	gl.GetShaderiv(shader, gl.COMPILE_STATUS, &status)
	if status == gl.FALSE {
		var logLength int32
		gl.GetShaderiv(shader, gl.INFO_LOG_LENGTH, &logLength)

		log := strings.Repeat("\x00", int(logLength+1))
		gl.GetShaderInfoLog(shader, logLength, nil, gl.Str(log))

		return 0, fmt.Errorf("failed to compile %v: %v", source, log)
	}
	return shader, nil
}