Files
nmage/buffers/framebuffer.go
2024-04-13 08:03:17 +04:00

296 lines
8.2 KiB
Go
Executable File

package buffers
import (
"github.com/bloeys/nmage/logging"
"github.com/go-gl/gl/v4.1-core/gl"
)
type FramebufferAttachmentType int32
const (
FramebufferAttachmentType_Unknown FramebufferAttachmentType = iota
FramebufferAttachmentType_Texture
FramebufferAttachmentType_Renderbuffer
)
func (f FramebufferAttachmentType) IsValid() bool {
switch f {
case FramebufferAttachmentType_Texture:
fallthrough
case FramebufferAttachmentType_Renderbuffer:
return true
default:
return false
}
}
type FramebufferAttachmentDataFormat int32
const (
FramebufferAttachmentDataFormat_Unknown FramebufferAttachmentDataFormat = iota
FramebufferAttachmentDataFormat_R32Int
FramebufferAttachmentDataFormat_RGBA8
FramebufferAttachmentDataFormat_SRGBA
FramebufferAttachmentDataFormat_Depth24Stencil8
)
func (f FramebufferAttachmentDataFormat) IsColorFormat() bool {
return f == FramebufferAttachmentDataFormat_R32Int ||
f == FramebufferAttachmentDataFormat_RGBA8 ||
f == FramebufferAttachmentDataFormat_SRGBA
}
func (f FramebufferAttachmentDataFormat) IsDepthFormat() bool {
return f == FramebufferAttachmentDataFormat_Depth24Stencil8
}
func (f FramebufferAttachmentDataFormat) GlInternalFormat() int32 {
switch f {
case FramebufferAttachmentDataFormat_R32Int:
return gl.R32I
case FramebufferAttachmentDataFormat_RGBA8:
return gl.RGB8
case FramebufferAttachmentDataFormat_SRGBA:
return gl.SRGB_ALPHA
case FramebufferAttachmentDataFormat_Depth24Stencil8:
return gl.DEPTH24_STENCIL8
default:
logging.ErrLog.Fatalf("unknown framebuffer attachment data format. Format=%d\n", f)
return 0
}
}
func (f FramebufferAttachmentDataFormat) GlFormat() uint32 {
switch f {
case FramebufferAttachmentDataFormat_R32Int:
return gl.RED_INTEGER
case FramebufferAttachmentDataFormat_RGBA8:
fallthrough
case FramebufferAttachmentDataFormat_SRGBA:
return gl.RGBA
case FramebufferAttachmentDataFormat_Depth24Stencil8:
return gl.DEPTH_STENCIL
default:
logging.ErrLog.Fatalf("unknown framebuffer attachment data format. Format=%d\n", f)
return 0
}
}
type FramebufferAttachment struct {
Id uint32
Type FramebufferAttachmentType
Format FramebufferAttachmentDataFormat
}
type Framebuffer struct {
Id uint32
Attachments []FramebufferAttachment
ColorAttachmentsCount uint32
Width uint32
Height uint32
}
func (fbo *Framebuffer) Bind() {
gl.BindFramebuffer(gl.FRAMEBUFFER, fbo.Id)
}
func (fbo *Framebuffer) BindWithViewport() {
gl.BindFramebuffer(gl.FRAMEBUFFER, fbo.Id)
gl.Viewport(0, 0, int32(fbo.Width), int32(fbo.Height))
}
func (fbo *Framebuffer) UnBind() {
gl.BindFramebuffer(gl.FRAMEBUFFER, 0)
}
func (fbo *Framebuffer) UnBindWithViewport(width, height uint32) {
gl.BindFramebuffer(gl.FRAMEBUFFER, 0)
gl.Viewport(0, 0, int32(width), int32(height))
}
// IsComplete returns true if OpenGL reports that the fbo is complete/usable.
// Note that this function binds and then unbinds the fbo
func (fbo *Framebuffer) IsComplete() bool {
fbo.Bind()
isComplete := gl.CheckFramebufferStatus(gl.FRAMEBUFFER) == gl.FRAMEBUFFER_COMPLETE
fbo.UnBind()
return isComplete
}
func (fbo *Framebuffer) HasColorAttachment() bool {
return fbo.ColorAttachmentsCount > 0
}
func (fbo *Framebuffer) HasDepthAttachment() bool {
for i := 0; i < len(fbo.Attachments); i++ {
a := &fbo.Attachments[i]
if a.Format.IsDepthFormat() {
return true
}
}
return false
}
func (fbo *Framebuffer) NewColorAttachment(
attachType FramebufferAttachmentType,
attachFormat FramebufferAttachmentDataFormat,
) {
if fbo.ColorAttachmentsCount == 8 {
logging.ErrLog.Fatalf("failed creating color attachment for framebuffer due it already having %d attached\n", fbo.ColorAttachmentsCount)
}
if !attachType.IsValid() {
logging.ErrLog.Fatalf("failed creating color attachment for framebuffer due to unknown attachment type. Type=%d\n", attachType)
}
if !attachFormat.IsColorFormat() {
logging.ErrLog.Fatalf("failed creating color attachment for framebuffer due to attachment data format not being a valid color type. Data format=%d\n", attachFormat)
}
a := FramebufferAttachment{
Type: attachType,
Format: attachFormat,
}
fbo.Bind()
if attachType == FramebufferAttachmentType_Texture {
// Create texture
gl.GenTextures(1, &a.Id)
if a.Id == 0 {
logging.ErrLog.Fatalf("failed to generate texture for framebuffer. GlError=%d\n", gl.GetError())
}
gl.BindTexture(gl.TEXTURE_2D, a.Id)
gl.TexImage2D(gl.TEXTURE_2D, 0, attachFormat.GlInternalFormat(), int32(fbo.Width), int32(fbo.Height), 0, attachFormat.GlFormat(), gl.UNSIGNED_BYTE, nil)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.BindTexture(gl.TEXTURE_2D, 0)
// Attach to fbo
gl.FramebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0+fbo.ColorAttachmentsCount, gl.TEXTURE_2D, a.Id, 0)
} else if attachType == FramebufferAttachmentType_Renderbuffer {
// Create rbo
gl.GenRenderbuffers(1, &a.Id)
if a.Id == 0 {
logging.ErrLog.Fatalf("failed to generate render buffer for framebuffer. GlError=%d\n", gl.GetError())
}
gl.BindRenderbuffer(gl.RENDERBUFFER, a.Id)
gl.RenderbufferStorage(gl.RENDERBUFFER, uint32(attachFormat.GlInternalFormat()), int32(fbo.Width), int32(fbo.Height))
gl.BindRenderbuffer(gl.RENDERBUFFER, 0)
// Attach to fbo
gl.FramebufferRenderbuffer(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0+fbo.ColorAttachmentsCount, gl.RENDERBUFFER, a.Id)
}
fbo.UnBind()
fbo.ColorAttachmentsCount++
fbo.Attachments = append(fbo.Attachments, a)
}
func (fbo *Framebuffer) NewDepthStencilAttachment(
attachType FramebufferAttachmentType,
attachFormat FramebufferAttachmentDataFormat,
) {
if fbo.HasDepthAttachment() {
logging.ErrLog.Fatalf("failed creating depth-stencil attachment for framebuffer because a depth-stencil attachment already exists\n")
}
if !attachType.IsValid() {
logging.ErrLog.Fatalf("failed creating depth-stencil attachment for framebuffer due to unknown attachment type. Type=%d\n", attachType)
}
if !attachFormat.IsDepthFormat() {
logging.ErrLog.Fatalf("failed creating depth-stencil attachment for framebuffer due to attachment data format not being a valid depth-stencil type. Data format=%d\n", attachFormat)
}
a := FramebufferAttachment{
Type: attachType,
Format: attachFormat,
}
fbo.Bind()
if attachType == FramebufferAttachmentType_Texture {
// Create texture
gl.GenTextures(1, &a.Id)
if a.Id == 0 {
logging.ErrLog.Fatalf("failed to generate texture for framebuffer. GlError=%d\n", gl.GetError())
}
gl.BindTexture(gl.TEXTURE_2D, a.Id)
gl.TexImage2D(gl.TEXTURE_2D, 0, attachFormat.GlInternalFormat(), int32(fbo.Width), int32(fbo.Height), 0, attachFormat.GlFormat(), gl.UNSIGNED_INT_24_8, nil)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
gl.BindTexture(gl.TEXTURE_2D, 0)
// Attach to fbo
gl.FramebufferTexture2D(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.TEXTURE_2D, a.Id, 0)
} else if attachType == FramebufferAttachmentType_Renderbuffer {
// Create rbo
gl.GenRenderbuffers(1, &a.Id)
if a.Id == 0 {
logging.ErrLog.Fatalf("failed to generate render buffer for framebuffer. GlError=%d\n", gl.GetError())
}
gl.BindRenderbuffer(gl.RENDERBUFFER, a.Id)
gl.RenderbufferStorage(gl.RENDERBUFFER, uint32(attachFormat.GlInternalFormat()), int32(fbo.Width), int32(fbo.Height))
gl.BindRenderbuffer(gl.RENDERBUFFER, 0)
// Attach to fbo
gl.FramebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.RENDERBUFFER, a.Id)
}
fbo.UnBind()
fbo.Attachments = append(fbo.Attachments, a)
}
func (fbo *Framebuffer) Delete() {
if fbo.Id == 0 {
return
}
gl.DeleteFramebuffers(1, &fbo.Id)
fbo.Id = 0
}
func NewFramebuffer(width, height uint32) Framebuffer {
// It is allowed to have attachments of differnt sizes in one FBO,
// but that complicates things (e.g. which size to use for gl.viewport) and I don't see much use
// for it now, so we will have all attachments share size
fbo := Framebuffer{
Width: width,
Height: height,
}
gl.GenFramebuffers(1, &fbo.Id)
if fbo.Id == 0 {
logging.ErrLog.Fatalf("failed to generate framebuffer. GlError=%d\n", gl.GetError())
}
return fbo
}