go-opengl-pixel/pixelgl/shader.go

395 lines
11 KiB
Go

package pixelgl
import (
"fmt"
"github.com/go-gl/gl/v3.3-core/gl"
"github.com/go-gl/mathgl/mgl32"
)
// UniformFormat defines names, purposes and types of uniform variables inside a shader.
//
// Example:
//
// UniformFormat{"transform": {Transform, Mat3}, "camera": {Camera, Mat3}}
type UniformFormat map[string]Attr
// Shader is an OpenGL shader program.
type Shader struct {
enabled bool
parent Doer
program uint32
vertexFormat VertexFormat
uniformFormat UniformFormat
uniforms map[Attr]int32
}
// NewShader creates a new shader program from the specified vertex shader and fragment shader sources.
//
// Note that vertexShader and fragmentShader parameters must contain the source code, they're not filenames.
func NewShader(parent Doer, vertexFormat VertexFormat, uniformFormat UniformFormat, vertexShader, fragmentShader string) (*Shader, error) {
shader := &Shader{
parent: parent,
vertexFormat: vertexFormat,
uniformFormat: uniformFormat,
uniforms: make(map[Attr]int32),
}
var err error
parent.Do(func(ctx Context) {
err = DoErr(func() error {
var vshader, fshader uint32
// vertex shader
{
vshader = gl.CreateShader(gl.VERTEX_SHADER)
src, free := gl.Strs(vertexShader)
defer free()
length := int32(len(vertexShader))
gl.ShaderSource(vshader, 1, src, &length)
gl.CompileShader(vshader)
var (
success int32
infoLog = make([]byte, 512)
)
gl.GetShaderiv(vshader, gl.COMPILE_STATUS, &success)
if success == 0 {
gl.GetShaderInfoLog(vshader, int32(len(infoLog)), nil, &infoLog[0])
return fmt.Errorf("error compiling vertex shader: %s", string(infoLog))
}
defer gl.DeleteShader(vshader)
}
// fragment shader
{
fshader = gl.CreateShader(gl.FRAGMENT_SHADER)
src, free := gl.Strs(fragmentShader)
defer free()
length := int32(len(fragmentShader))
gl.ShaderSource(fshader, 1, src, &length)
gl.CompileShader(fshader)
var (
success int32
infoLog = make([]byte, 512)
)
gl.GetShaderiv(fshader, gl.COMPILE_STATUS, &success)
if success == 0 {
gl.GetShaderInfoLog(fshader, int32(len(infoLog)), nil, &infoLog[0])
return fmt.Errorf("error compiling fragment shader: %s", string(infoLog))
}
defer gl.DeleteShader(fshader)
}
// shader program
{
shader.program = gl.CreateProgram()
gl.AttachShader(shader.program, vshader)
gl.AttachShader(shader.program, fshader)
gl.LinkProgram(shader.program)
var (
success int32
infoLog = make([]byte, 512)
)
gl.GetProgramiv(shader.program, gl.LINK_STATUS, &success)
if success == 0 {
gl.GetProgramInfoLog(shader.program, int32(len(infoLog)), nil, &infoLog[0])
return fmt.Errorf("error linking shader program: %s", string(infoLog))
}
}
// uniforms
for uname, utype := range uniformFormat {
ulocation := gl.GetUniformLocation(shader.program, gl.Str(uname+"\x00"))
if ulocation == -1 {
gl.DeleteProgram(shader.program)
return fmt.Errorf("shader does not contain uniform '%s'", uname)
}
if _, ok := shader.uniforms[utype]; ok {
gl.DeleteProgram(shader.program)
return fmt.Errorf("failed to create shader: invalid uniform format: duplicate uniform attribute")
}
shader.uniforms[utype] = ulocation
}
return nil
})
})
if err != nil {
return nil, err
}
return shader, nil
}
// Delete deletes a shader program. Don't use a shader after deletion.
func (s *Shader) Delete() {
s.parent.Do(func(ctx Context) {
DoNoBlock(func() {
gl.DeleteProgram(s.program)
})
})
}
// ID returns an OpenGL identifier of a shader program.
func (s *Shader) ID() uint32 {
return s.program
}
// VertexFormat returns the vertex attribute format of this shader. Do not change it.
func (s *Shader) VertexFormat() VertexFormat {
return s.vertexFormat
}
// UniformFormat returns the uniform attribute format of this shader. Do not change it.
func (s *Shader) UniformFormat() UniformFormat {
return s.uniformFormat
}
// SetUniformInt sets the value of an uniform attribute Attr{Purpose: purpose, Type: Int}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformInt(purpose AttrPurpose, value int32) (ok bool) {
attr := Attr{Purpose: purpose, Type: Int}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.Uniform1i(s.uniforms[attr], value)
})
})
return true
}
// SetUniformFloat sets the value of an uniform attribute Attr{Purpose: purpose, Type: Float}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformFloat(purpose AttrPurpose, value float32) (ok bool) {
attr := Attr{Purpose: purpose, Type: Float}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.Uniform1f(s.uniforms[attr], value)
})
})
return true
}
// SetUniformVec2 sets the value of an uniform attribute Attr{Purpose: purpose, Type: Vec2}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformVec2(purpose AttrPurpose, value mgl32.Vec2) (ok bool) {
attr := Attr{Purpose: purpose, Type: Vec2}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.Uniform2f(s.uniforms[attr], value[0], value[1])
})
})
return true
}
// SetUniformVec3 sets the value of an uniform attribute Attr{Purpose: purpose, Type: Vec3}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformVec3(purpose AttrPurpose, value mgl32.Vec3) (ok bool) {
attr := Attr{Purpose: purpose, Type: Vec3}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.Uniform3f(s.uniforms[attr], value[0], value[1], value[2])
})
})
return true
}
// SetUniformVec4 sets the value of an uniform attribute Attr{Purpose: purpose, Type: Vec4}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformVec4(purpose AttrPurpose, value mgl32.Vec4) (ok bool) {
attr := Attr{Purpose: purpose, Type: Vec4}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.Uniform4f(s.uniforms[attr], value[0], value[1], value[2], value[3])
})
})
return true
}
// SetUniformMat2 sets the value of an uniform attribute Attr{Purpose: purpose, Type: Mat2}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformMat2(purpose AttrPurpose, value mgl32.Mat2) (ok bool) {
attr := Attr{Purpose: purpose, Type: Mat2}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.UniformMatrix2fv(s.uniforms[attr], 1, false, &value[0])
})
})
return true
}
// SetUniformMat23 sets the value of an uniform attribute Attr{Purpose: purpose, Type: Mat23}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformMat23(purpose AttrPurpose, value mgl32.Mat2x3) (ok bool) {
attr := Attr{Purpose: purpose, Type: Mat23}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.UniformMatrix2x3fv(s.uniforms[attr], 1, false, &value[0])
})
})
return true
}
// SetUniformMat24 sets the value of an uniform attribute Attr{Purpose: purpose, Type: Mat24}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformMat24(purpose AttrPurpose, value mgl32.Mat2x4) (ok bool) {
attr := Attr{Purpose: purpose, Type: Mat24}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.UniformMatrix2x4fv(s.uniforms[attr], 1, false, &value[0])
})
})
return true
}
// SetUniformMat3 sets the value of an uniform attribute Attr{Purpose: purpose, Type: Mat3}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformMat3(purpose AttrPurpose, value mgl32.Mat3) (ok bool) {
attr := Attr{Purpose: purpose, Type: Mat3}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.UniformMatrix3fv(s.uniforms[attr], 1, false, &value[0])
})
})
return true
}
// SetUniformMat32 sets the value of an uniform attribute Attr{Purpose: purpose, Type: Mat32}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformMat32(purpose AttrPurpose, value mgl32.Mat3x2) (ok bool) {
attr := Attr{Purpose: purpose, Type: Mat32}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.UniformMatrix3x2fv(s.uniforms[attr], 1, false, &value[0])
})
})
return true
}
// SetUniformMat34 sets the value of an uniform attribute Attr{Purpose: purpose, Type: Mat34}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformMat34(purpose AttrPurpose, value mgl32.Mat3x4) (ok bool) {
attr := Attr{Purpose: purpose, Type: Mat34}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.UniformMatrix3x4fv(s.uniforms[attr], 1, false, &value[0])
})
})
return true
}
// SetUniformMat4 sets the value of an uniform attribute Attr{Purpose: purpose, Type: Mat4}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformMat4(purpose AttrPurpose, value mgl32.Mat4) (ok bool) {
attr := Attr{Purpose: purpose, Type: Mat4}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.UniformMatrix4fv(s.uniforms[attr], 1, false, &value[0])
})
})
return true
}
// SetUniformMat42 sets the value of an uniform attribute Attr{Purpose: purpose, Type: Mat42}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformMat42(purpose AttrPurpose, value mgl32.Mat4x2) (ok bool) {
attr := Attr{Purpose: purpose, Type: Mat42}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.UniformMatrix4x2fv(s.uniforms[attr], 1, false, &value[0])
})
})
return true
}
// SetUniformMat43 sets the value of an uniform attribute Attr{Purpose: purpose, Type: Mat43}.
//
// Returns false if the attribute does not exist.
func (s *Shader) SetUniformMat43(purpose AttrPurpose, value mgl32.Mat4x3) (ok bool) {
attr := Attr{Purpose: purpose, Type: Mat43}
if _, ok := s.uniforms[attr]; !ok {
return false
}
s.Do(func(Context) {
DoNoBlock(func() {
gl.UniformMatrix4x3fv(s.uniforms[attr], 1, false, &value[0])
})
})
return true
}
// Do stars using a shader, executes sub, and stops using it.
func (s *Shader) Do(sub func(Context)) {
s.parent.Do(func(ctx Context) {
if s.enabled {
sub(ctx.WithShader(s))
return
}
DoNoBlock(func() {
gl.UseProgram(s.program)
})
s.enabled = true
sub(ctx.WithShader(s))
s.enabled = false
DoNoBlock(func() {
gl.UseProgram(0)
})
})
}