gpu: Move Bind methods to Backend

Having Backend.Bind* methods better matches both opengl and d3d.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/headless/headless.go

@@ -59,7 +59,7 @@ func NewWindow(width, height int) (*Window, error) {
 			fboTex.Release()
 			return err
 		}
-		fbo.Bind()
+		backend.BindFramebuffer(fbo)
 		gp, err := gpu.New(backend)
 		if err != nil {
 			fbo.Release()

gpu/backend.go

@@ -37,6 +37,13 @@ type Backend interface {
 	SetDepthTest(enable bool)
 	DepthMask(mask bool)
 	BlendFunc(sfactor, dfactor BlendFactor)
+
+	BindInputLayout(i InputLayout)
+	BindProgram(p Program)
+	BindFramebuffer(f Framebuffer)
+	BindTexture(unit int, t Texture)
+	BindVertexBuffer(b Buffer, stride, offset int)
+	BindIndexBuffer(b Buffer)
 }
 
 type ShaderSources struct {
@@ -83,7 +90,6 @@ type InputDesc struct {
 // InputLayout is the backend specific representation of the mapping
 // between Buffers and shader attributes.
 type InputLayout interface {
-	Bind()
 	Release()
 }
 
@@ -110,21 +116,17 @@ type Caps struct {
 }
 
 type Program interface {
-	Bind()
 	Release()
 	SetVertexUniforms(buf Buffer)
 	SetFragmentUniforms(buf Buffer)
 }
 
 type Buffer interface {
-	BindVertex(stride, offset int)
-	BindIndex()
 	Release()
 	Upload(data []byte)
 }
 
 type Framebuffer interface {
-	Bind()
 	Invalidate()
 	Release()
 	ReadPixels(src image.Rectangle, pixels []byte) error
@@ -140,7 +142,6 @@ type Timer interface {
 type Texture interface {
 	Upload(img *image.RGBA)
 	Release()
-	Bind(unit int)
 }
 
 const (

gpu/gl/backend.go

@@ -59,7 +59,7 @@ type gpuTexture struct {
 }
 
 type gpuFramebuffer struct {
-	funcs    Functions
+	backend *Backend
 	obj      Framebuffer
 	hasDepth bool
 	depthBuf Renderbuffer
@@ -129,12 +129,12 @@ func NewBackend(f Functions) (*Backend, error) {
 	}
 	defFBO := Framebuffer(f.GetBinding(FRAMEBUFFER_BINDING))
 	b := &Backend{
-		defFBO:      &gpuFramebuffer{funcs: f, obj: defFBO},
 		funcs:       f,
 		floatTriple: floatTriple,
 		alphaTriple: alphaTripleFor(ver),
 		srgbaTriple: srgbaTriple,
 	}
+	b.defFBO = &gpuFramebuffer{backend: b, obj: defFBO}
 	if hasExtension(exts, "GL_EXT_disjoint_timer_query_webgl2") || hasExtension(exts, "GL_EXT_disjoint_timer_query") {
 		b.feats.Features |= gpu.FeatureTimers
 	}
@@ -170,8 +170,8 @@ func (b *Backend) NewFramebuffer(tex gpu.Texture, depthBits int) (gpu.Framebuffe
 	glErr(b.funcs)
 	gltex := tex.(*gpuTexture)
 	fb := b.funcs.CreateFramebuffer()
-	fbo := &gpuFramebuffer{funcs: b.funcs, obj: fb}
+	fbo := &gpuFramebuffer{backend: b, obj: fb}
-	fbo.Bind()
+	b.BindFramebuffer(fbo)
 	if err := glErr(b.funcs); err != nil {
 		fbo.Release()
 		return nil, err
@@ -217,7 +217,7 @@ func (b *Backend) NewTexture(format gpu.TextureFormat, width, height int, minFil
 	default:
 		return nil, errors.New("unsupported texture format")
 	}
-	tex.Bind(0)
+	b.BindTexture(0, tex)
 	b.funcs.TexParameteri(TEXTURE_2D, TEXTURE_MAG_FILTER, toTexFilter(magFilter))
 	b.funcs.TexParameteri(TEXTURE_2D, TEXTURE_MIN_FILTER, toTexFilter(minFilter))
 	b.funcs.TexParameteri(TEXTURE_2D, TEXTURE_WRAP_S, CLAMP_TO_EDGE)
@@ -430,7 +430,7 @@ func (b *Backend) NewProgram(vssrc, fssrc gpu.ShaderSources) (gpu.Program, error
 		obj:     p,
 		nattr:   len(attr),
 	}
-	gpuProg.Bind()
+	b.BindProgram(gpuProg)
 	// Bind texture uniforms.
 	for _, tex := range vssrc.Textures {
 		u := b.funcs.GetUniformLocation(p, tex.Name)
@@ -467,9 +467,10 @@ func (p *gpuProgram) updateUniforms() {
 	p.fragUniforms.update(p.backend.funcs)
 }
 
-func (p *gpuProgram) Bind() {
+func (b *Backend) BindProgram(prog gpu.Program) {
-	p.backend.useProgram(p)
+	p := prog.(*gpuProgram)
-	p.backend.enableVertexArrays(p.nattr)
+	b.useProgram(p)
+	b.enableVertexArrays(p.nattr)
 }
 
 func (p *gpuProgram) Release() {
@@ -553,11 +554,12 @@ func (b *gpuBuffer) Release() {
 	}
 }
 
-func (b *gpuBuffer) BindVertex(stride, offset int) {
+func (b *Backend) BindVertexBuffer(buf gpu.Buffer, stride, offset int) {
-	if b.typ&gpu.BufferBindingVertices == 0 {
+	gbuf := buf.(*gpuBuffer)
+	if gbuf.typ&gpu.BufferBindingVertices == 0 {
 		panic("not a vertex buffer")
 	}
-	b.backend.state.buffer = bufferBinding{buf: b, stride: stride, offset: offset}
+	b.state.buffer = bufferBinding{buf: gbuf, stride: stride, offset: offset}
 }
 
 func (b *Backend) setupVertexArrays() {
@@ -582,36 +584,37 @@ func (b *Backend) setupVertexArrays() {
 	}
 }
 
-func (b *gpuBuffer) BindIndex() {
+func (b *Backend) BindIndexBuffer(buf gpu.Buffer) {
-	if b.typ&gpu.BufferBindingIndices == 0 {
+	gbuf := buf.(*gpuBuffer)
+	if gbuf.typ&gpu.BufferBindingIndices == 0 {
 		panic("not an index buffer")
 	}
-	b.backend.funcs.BindBuffer(ELEMENT_ARRAY_BUFFER, b.obj)
+	b.funcs.BindBuffer(ELEMENT_ARRAY_BUFFER, gbuf.obj)
 }
 
 func (f *gpuFramebuffer) ReadPixels(src image.Rectangle, pixels []byte) error {
-	glErr(f.funcs)
+	glErr(f.backend.funcs)
-	f.Bind()
+	f.backend.BindFramebuffer(f)
 	if len(pixels) < src.Dx()*src.Dy() {
 		return errors.New("unexpected RGBA size")
 	}
-	f.funcs.ReadPixels(src.Min.X, src.Min.Y, src.Dx(), src.Dy(), RGBA, UNSIGNED_BYTE, pixels)
+	f.backend.funcs.ReadPixels(src.Min.X, src.Min.Y, src.Dx(), src.Dy(), RGBA, UNSIGNED_BYTE, pixels)
-	return glErr(f.funcs)
+	return glErr(f.backend.funcs)
 }
 
-func (f *gpuFramebuffer) Bind() {
+func (b *Backend) BindFramebuffer(fbo gpu.Framebuffer) {
-	f.funcs.BindFramebuffer(FRAMEBUFFER, f.obj)
+	b.funcs.BindFramebuffer(FRAMEBUFFER, fbo.(*gpuFramebuffer).obj)
 }
 
 func (f *gpuFramebuffer) Invalidate() {
-	f.Bind()
+	f.backend.BindFramebuffer(f)
-	f.funcs.InvalidateFramebuffer(FRAMEBUFFER, COLOR_ATTACHMENT0)
+	f.backend.funcs.InvalidateFramebuffer(FRAMEBUFFER, COLOR_ATTACHMENT0)
 }
 
 func (f *gpuFramebuffer) Release() {
-	f.funcs.DeleteFramebuffer(f.obj)
+	f.backend.funcs.DeleteFramebuffer(f.obj)
 	if f.hasDepth {
-		f.funcs.DeleteRenderbuffer(f.depthBuf)
+		f.backend.funcs.DeleteRenderbuffer(f.depthBuf)
 	}
 }
 
@@ -626,8 +629,8 @@ func toTexFilter(f gpu.TextureFilter) int {
 	}
 }
 
-func (t *gpuTexture) Bind(unit int) {
+func (b *Backend) BindTexture(unit int, t gpu.Texture) {
-	t.backend.bindTexture(unit, t)
+	b.bindTexture(unit, t.(*gpuTexture))
 }
 
 func (t *gpuTexture) Release() {
@@ -635,7 +638,7 @@ func (t *gpuTexture) Release() {
 }
 
 func (t *gpuTexture) Upload(img *image.RGBA) {
-	t.Bind(0)
+	t.backend.BindTexture(0, t)
 	var pixels []byte
 	b := img.Bounds()
 	w, h := b.Dx(), b.Dy()
@@ -672,8 +675,8 @@ func (t *gpuTimer) Duration() (time.Duration, bool) {
 	return time.Duration(nanos), true
 }
 
-func (l *gpuInputLayout) Bind() {
+func (b *Backend) BindInputLayout(l gpu.InputLayout) {
-	l.backend.state.layout = l
+	b.state.layout = l.(*gpuInputLayout)
 }
 
 func (l *gpuInputLayout) Release() {}

gpu/gpu.go

@@ -496,7 +496,7 @@ func (r *renderer) stencilClips(pathCache *opCache, ops []*pathOp) {
 		if fbo != p.place.Idx {
 			fbo = p.place.Idx
 			f := r.pather.stenciler.cover(fbo)
-			f.fbo.Bind()
+			r.ctx.BindFramebuffer(f.fbo)
 			r.ctx.Clear(BufferAttachmentColor)
 		}
 		data, _ := pathCache.get(p.pathKey)
@@ -511,8 +511,8 @@ func (r *renderer) intersect(ops []imageOp) {
 	}
 	fbo := -1
 	r.pather.stenciler.beginIntersect(r.intersections.sizes)
-	r.blitter.quadVerts.BindVertex(4*4, 0)
+	r.ctx.BindVertexBuffer(r.blitter.quadVerts, 4*4, 0)
-	r.pather.stenciler.iprog.layout.Bind()
+	r.ctx.BindInputLayout(r.pather.stenciler.iprog.layout)
 	for _, img := range ops {
 		if img.clipType != clipTypeIntersection {
 			continue
@@ -520,7 +520,7 @@ func (r *renderer) intersect(ops []imageOp) {
 		if fbo != img.place.Idx {
 			fbo = img.place.Idx
 			f := r.pather.stenciler.intersections.fbos[fbo]
-			f.fbo.Bind()
+			r.ctx.BindFramebuffer(f.fbo)
 			r.ctx.Clear(BufferAttachmentColor)
 		}
 		r.ctx.Viewport(img.place.Pos.X, img.place.Pos.Y, img.clip.Dx(), img.clip.Dy())
@@ -542,7 +542,7 @@ func (r *renderer) intersectPath(p *pathOp, clip image.Rectangle) {
 		Max: o.Add(clip.Size()),
 	}
 	fbo := r.pather.stenciler.cover(p.place.Idx)
-	fbo.tex.Bind(0)
+	r.ctx.BindTexture(0, fbo.tex)
 	coverScale, coverOff := texSpaceTransform(toRectF(uv), fbo.size)
 	r.pather.stenciler.iprog.uniforms.vert.uvScale = [2]float32{coverScale.X, coverScale.Y}
 	r.pather.stenciler.iprog.uniforms.vert.uvOffset = [2]float32{coverOff.X, coverOff.Y}
@@ -819,15 +819,15 @@ func (d *drawState) materialFor(cache *resourceCache, rect f32.Rectangle, off f3
 
 func (r *renderer) drawZOps(ops []imageOp) {
 	r.ctx.SetDepthTest(true)
-	r.blitter.quadVerts.BindVertex(4*4, 0)
+	r.ctx.BindVertexBuffer(r.blitter.quadVerts, 4*4, 0)
-	r.blitter.layout.Bind()
+	r.ctx.BindInputLayout(r.blitter.layout)
 	// Render front to back.
 	for i := len(ops) - 1; i >= 0; i-- {
 		img := ops[i]
 		m := img.material
 		switch m.material {
 		case materialTexture:
-			r.texHandle(m.texture).Bind(0)
+			r.ctx.BindTexture(0, r.texHandle(m.texture))
 		}
 		drc := img.clip
 		scale, off := clipSpaceTransform(drc, r.blitter.viewport)
@@ -840,14 +840,14 @@ func (r *renderer) drawOps(ops []imageOp) {
 	r.ctx.SetDepthTest(true)
 	r.ctx.DepthMask(false)
 	r.ctx.BlendFunc(BlendFactorOne, BlendFactorOneMinusSrcAlpha)
-	r.blitter.quadVerts.BindVertex(4*4, 0)
+	r.ctx.BindVertexBuffer(r.blitter.quadVerts, 4*4, 0)
-	r.pather.coverer.layout.Bind()
+	r.ctx.BindInputLayout(r.pather.coverer.layout)
 	var coverTex Texture
 	for _, img := range ops {
 		m := img.material
 		switch m.material {
 		case materialTexture:
-			r.texHandle(m.texture).Bind(0)
+			r.ctx.BindTexture(0, r.texHandle(m.texture))
 		}
 		drc := img.clip
 		scale, off := clipSpaceTransform(drc, r.blitter.viewport)
@@ -863,7 +863,7 @@ func (r *renderer) drawOps(ops []imageOp) {
 		}
 		if coverTex != fbo.tex {
 			coverTex = fbo.tex
-			coverTex.Bind(1)
+			r.ctx.BindTexture(1, coverTex)
 		}
 		uv := image.Rectangle{
 			Min: img.place.Pos,
@@ -894,7 +894,7 @@ func gamma(r, g, b, a uint32) [4]float32 {
 
 func (b *blitter) blit(z float32, mat materialType, col [4]float32, scale, off, uvScale, uvOff f32.Point) {
 	p := b.prog[mat]
-	p.prog.Bind()
+	b.ctx.BindProgram(p.prog)
 	var uniforms *blitUniforms
 	switch mat {
 	case materialColor:

gpu/path.go

@@ -296,17 +296,17 @@ func (s *stenciler) beginIntersect(sizes []image.Point) {
 	// no floating point support is available.
 	s.intersections.resize(s.ctx, sizes)
 	s.ctx.ClearColor(1.0, 0.0, 0.0, 0.0)
-	s.iprog.prog.prog.Bind()
+	s.ctx.BindProgram(s.iprog.prog.prog)
 }
 
 func (s *stenciler) endIntersect() {
-	s.defFBO.Bind()
+	s.ctx.BindFramebuffer(s.defFBO)
 }
 
 func (s *stenciler) invalidateFBO() {
 	s.intersections.invalidate(s.ctx)
 	s.fbos.invalidate(s.ctx)
-	s.defFBO.Bind()
+	s.ctx.BindFramebuffer(s.defFBO)
 }
 
 func (s *stenciler) cover(idx int) stencilFBO {
@@ -317,9 +317,9 @@ func (s *stenciler) begin(sizes []image.Point) {
 	s.ctx.BlendFunc(BlendFactorOne, BlendFactorOne)
 	s.fbos.resize(s.ctx, sizes)
 	s.ctx.ClearColor(0.0, 0.0, 0.0, 0.0)
-	s.prog.prog.prog.Bind()
+	s.ctx.BindProgram(s.prog.prog.prog)
-	s.prog.layout.Bind()
+	s.ctx.BindInputLayout(s.prog.layout)
-	s.indexBuf.BindIndex()
+	s.ctx.BindIndexBuffer(s.indexBuf)
 }
 
 func (s *stenciler) stencilPath(bounds image.Rectangle, offset f32.Point, uv image.Point, data *pathData) {
@@ -341,14 +341,14 @@ func (s *stenciler) stencilPath(bounds image.Rectangle, offset f32.Point, uv ima
 			batch = max
 		}
 		off := path.VertStride * start * 4
-		data.data.BindVertex(path.VertStride, off)
+		s.ctx.BindVertexBuffer(data.data, path.VertStride, off)
 		s.ctx.DrawElements(DrawModeTriangles, 0, batch*6)
 		start += batch
 	}
 }
 
 func (s *stenciler) end() {
-	s.defFBO.Bind()
+	s.ctx.BindFramebuffer(s.defFBO)
 }
 
 func (p *pather) cover(z float32, mat materialType, col [4]float32, scale, off, uvScale, uvOff, coverScale, coverOff f32.Point) {
@@ -357,7 +357,7 @@ func (p *pather) cover(z float32, mat materialType, col [4]float32, scale, off,
 
 func (c *coverer) cover(z float32, mat materialType, col [4]float32, scale, off, uvScale, uvOff, coverScale, coverOff f32.Point) {
 	p := c.prog[mat]
-	p.prog.Bind()
+	c.ctx.BindProgram(p.prog)
 	var uniforms *coverUniforms
 	switch mat {
 	case materialColor: