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NoiseTorch/vendor/gioui.org/gpu/gpu.go

1184 lines
31 KiB
Go

// SPDX-License-Identifier: Unlicense OR MIT
/*
Package gpu implements the rendering of Gio drawing operations. It
is used by package app and package app/headless and is otherwise not
useful except for integrating with external window implementations.
*/
package gpu
import (
"encoding/binary"
"fmt"
"image"
"image/color"
"math"
"reflect"
"time"
"unsafe"
"gioui.org/f32"
"gioui.org/gpu/backend"
"gioui.org/internal/f32color"
"gioui.org/internal/opconst"
"gioui.org/internal/ops"
gunsafe "gioui.org/internal/unsafe"
"gioui.org/layout"
"gioui.org/op"
"gioui.org/op/paint"
)
type GPU struct {
cache *resourceCache
defFBO backend.Framebuffer
profile string
timers *timers
frameStart time.Time
zopsTimer, stencilTimer, coverTimer, cleanupTimer *timer
drawOps drawOps
ctx backend.Device
renderer *renderer
}
type renderer struct {
ctx backend.Device
blitter *blitter
pather *pather
packer packer
intersections packer
}
type drawOps struct {
profile bool
reader ops.Reader
cache *resourceCache
vertCache []byte
viewport image.Point
clearColor f32color.RGBA
imageOps []imageOp
// zimageOps are the rectangle clipped opaque images
// that can use fast front-to-back rendering with z-test
// and no blending.
zimageOps []imageOp
pathOps []*pathOp
pathOpCache []pathOp
qs quadSplitter
pathCache *opCache
}
type drawState struct {
clip f32.Rectangle
t f32.Affine2D
cpath *pathOp
rect bool
z int
matType materialType
// Current paint.ImageOp
image imageOpData
// Current paint.ColorOp, if any.
color color.RGBA
}
type pathOp struct {
off f32.Point
// clip is the union of all
// later clip rectangles.
clip image.Rectangle
bounds f32.Rectangle
pathKey ops.Key
path bool
pathVerts []byte
parent *pathOp
place placement
}
type imageOp struct {
z float32
path *pathOp
off f32.Point
clip image.Rectangle
material material
clipType clipType
place placement
}
type material struct {
material materialType
opaque bool
// For materialTypeColor.
color f32color.RGBA
// For materialTypeTexture.
texture *texture
uvTrans f32.Affine2D
}
// clipOp is the shadow of clip.Op.
type clipOp struct {
bounds f32.Rectangle
}
// imageOpData is the shadow of paint.ImageOp.
type imageOpData struct {
rect image.Rectangle
src *image.RGBA
handle interface{}
}
func (op *clipOp) decode(data []byte) {
if opconst.OpType(data[0]) != opconst.TypeClip {
panic("invalid op")
}
bo := binary.LittleEndian
r := f32.Rectangle{
Min: f32.Point{
X: math.Float32frombits(bo.Uint32(data[1:])),
Y: math.Float32frombits(bo.Uint32(data[5:])),
},
Max: f32.Point{
X: math.Float32frombits(bo.Uint32(data[9:])),
Y: math.Float32frombits(bo.Uint32(data[13:])),
},
}
*op = clipOp{
bounds: r,
}
}
func decodeImageOp(data []byte, refs []interface{}) imageOpData {
if opconst.OpType(data[0]) != opconst.TypeImage {
panic("invalid op")
}
handle := refs[1]
if handle == nil {
return imageOpData{}
}
bo := binary.LittleEndian
return imageOpData{
rect: image.Rectangle{
Min: image.Point{
X: int(bo.Uint32(data[1:])),
Y: int(bo.Uint32(data[5:])),
},
Max: image.Point{
X: int(bo.Uint32(data[9:])),
Y: int(bo.Uint32(data[13:])),
},
},
src: refs[0].(*image.RGBA),
handle: handle,
}
}
func decodeColorOp(data []byte) color.RGBA {
if opconst.OpType(data[0]) != opconst.TypeColor {
panic("invalid op")
}
return color.RGBA{
R: data[1],
G: data[2],
B: data[3],
A: data[4],
}
}
func decodePaintOp(data []byte) paint.PaintOp {
bo := binary.LittleEndian
if opconst.OpType(data[0]) != opconst.TypePaint {
panic("invalid op")
}
r := f32.Rectangle{
Min: f32.Point{
X: math.Float32frombits(bo.Uint32(data[1:])),
Y: math.Float32frombits(bo.Uint32(data[5:])),
},
Max: f32.Point{
X: math.Float32frombits(bo.Uint32(data[9:])),
Y: math.Float32frombits(bo.Uint32(data[13:])),
},
}
return paint.PaintOp{
Rect: r,
}
}
type clipType uint8
type resource interface {
release()
}
type texture struct {
src *image.RGBA
tex backend.Texture
}
type blitter struct {
ctx backend.Device
viewport image.Point
prog [2]*program
layout backend.InputLayout
colUniforms *blitColUniforms
texUniforms *blitTexUniforms
quadVerts backend.Buffer
}
type blitColUniforms struct {
vert struct {
blitUniforms
_ [12]byte // Padding to a multiple of 16.
}
frag struct {
colorUniforms
}
}
type blitTexUniforms struct {
vert struct {
blitUniforms
_ [12]byte // Padding to a multiple of 16.
}
}
type uniformBuffer struct {
buf backend.Buffer
ptr []byte
}
type program struct {
prog backend.Program
vertUniforms *uniformBuffer
fragUniforms *uniformBuffer
}
type blitUniforms struct {
transform [4]float32
uvTransformR1 [4]float32
uvTransformR2 [4]float32
z float32
}
type colorUniforms struct {
color f32color.RGBA
}
type materialType uint8
const (
clipTypeNone clipType = iota
clipTypePath
clipTypeIntersection
)
const (
materialColor materialType = iota
materialTexture
)
func New(ctx backend.Device) (*GPU, error) {
defFBO := ctx.CurrentFramebuffer()
g := &GPU{
defFBO: defFBO,
cache: newResourceCache(),
}
g.drawOps.pathCache = newOpCache()
if err := g.init(ctx); err != nil {
return nil, err
}
return g, nil
}
func (g *GPU) init(ctx backend.Device) error {
g.ctx = ctx
g.renderer = newRenderer(ctx)
return nil
}
func (g *GPU) Release() {
g.renderer.release()
g.drawOps.pathCache.release()
g.cache.release()
if g.timers != nil {
g.timers.release()
}
}
func (g *GPU) Collect(viewport image.Point, frameOps *op.Ops) {
g.renderer.blitter.viewport = viewport
g.renderer.pather.viewport = viewport
g.drawOps.reset(g.cache, viewport)
g.drawOps.collect(g.cache, frameOps, viewport)
g.frameStart = time.Now()
if g.drawOps.profile && g.timers == nil && g.ctx.Caps().Features.Has(backend.FeatureTimers) {
g.timers = newTimers(g.ctx)
g.zopsTimer = g.timers.newTimer()
g.stencilTimer = g.timers.newTimer()
g.coverTimer = g.timers.newTimer()
g.cleanupTimer = g.timers.newTimer()
}
for _, p := range g.drawOps.pathOps {
if v, exists := g.drawOps.pathCache.get(p.pathKey); !exists || v.data.data == nil {
data := buildPath(g.ctx, p.pathVerts)
g.drawOps.pathCache.put(p.pathKey, opCacheValue{
data: data,
bounds: p.bounds,
})
}
p.pathVerts = nil
}
}
func (g *GPU) BeginFrame() {
g.ctx.BeginFrame()
defer g.ctx.EndFrame()
viewport := g.renderer.blitter.viewport
for _, img := range g.drawOps.imageOps {
expandPathOp(img.path, img.clip)
}
if g.drawOps.profile {
g.zopsTimer.begin()
}
g.ctx.BindFramebuffer(g.defFBO)
g.ctx.DepthFunc(backend.DepthFuncGreater)
g.ctx.ClearDepth(0.0)
g.ctx.Clear(g.drawOps.clearColor.Float32())
g.ctx.Viewport(0, 0, viewport.X, viewport.Y)
g.renderer.drawZOps(g.drawOps.zimageOps)
g.zopsTimer.end()
g.stencilTimer.begin()
g.ctx.SetBlend(true)
g.renderer.packStencils(&g.drawOps.pathOps)
g.renderer.stencilClips(g.drawOps.pathCache, g.drawOps.pathOps)
g.renderer.packIntersections(g.drawOps.imageOps)
g.renderer.intersect(g.drawOps.imageOps)
g.stencilTimer.end()
g.coverTimer.begin()
g.ctx.BindFramebuffer(g.defFBO)
g.ctx.Viewport(0, 0, viewport.X, viewport.Y)
g.renderer.drawOps(g.drawOps.imageOps)
g.ctx.SetBlend(false)
g.renderer.pather.stenciler.invalidateFBO()
g.coverTimer.end()
g.ctx.BindFramebuffer(g.defFBO)
}
func (g *GPU) EndFrame() {
g.cleanupTimer.begin()
g.cache.frame()
g.drawOps.pathCache.frame()
g.cleanupTimer.end()
if g.drawOps.profile && g.timers.ready() {
zt, st, covt, cleant := g.zopsTimer.Elapsed, g.stencilTimer.Elapsed, g.coverTimer.Elapsed, g.cleanupTimer.Elapsed
ft := zt + st + covt + cleant
q := 100 * time.Microsecond
zt, st, covt = zt.Round(q), st.Round(q), covt.Round(q)
frameDur := time.Since(g.frameStart).Round(q)
ft = ft.Round(q)
g.profile = fmt.Sprintf("draw:%7s gpu:%7s zt:%7s st:%7s cov:%7s", frameDur, ft, zt, st, covt)
}
}
func (g *GPU) Profile() string {
return g.profile
}
func (r *renderer) texHandle(t *texture) backend.Texture {
if t.tex != nil {
return t.tex
}
tex, err := r.ctx.NewTexture(backend.TextureFormatSRGB, t.src.Bounds().Dx(), t.src.Bounds().Dy(), backend.FilterLinear, backend.FilterLinear, backend.BufferBindingTexture)
if err != nil {
panic(err)
}
tex.Upload(t.src)
t.tex = tex
return t.tex
}
func (t *texture) release() {
if t.tex != nil {
t.tex.Release()
}
}
func newRenderer(ctx backend.Device) *renderer {
r := &renderer{
ctx: ctx,
blitter: newBlitter(ctx),
pather: newPather(ctx),
}
r.packer.maxDim = ctx.Caps().MaxTextureSize
r.intersections.maxDim = r.packer.maxDim
return r
}
func (r *renderer) release() {
r.pather.release()
r.blitter.release()
}
func newBlitter(ctx backend.Device) *blitter {
quadVerts, err := ctx.NewImmutableBuffer(backend.BufferBindingVertices,
gunsafe.BytesView([]float32{
-1, +1, 0, 0,
+1, +1, 1, 0,
-1, -1, 0, 1,
+1, -1, 1, 1,
}),
)
if err != nil {
panic(err)
}
b := &blitter{
ctx: ctx,
quadVerts: quadVerts,
}
b.colUniforms = new(blitColUniforms)
b.texUniforms = new(blitTexUniforms)
prog, layout, err := createColorPrograms(ctx, shader_blit_vert, shader_blit_frag,
[2]interface{}{&b.colUniforms.vert, &b.texUniforms.vert}, [2]interface{}{&b.colUniforms.frag, nil})
if err != nil {
panic(err)
}
b.prog = prog
b.layout = layout
return b
}
func (b *blitter) release() {
b.quadVerts.Release()
for _, p := range b.prog {
p.Release()
}
b.layout.Release()
}
func createColorPrograms(b backend.Device, vsSrc backend.ShaderSources, fsSrc [2]backend.ShaderSources, vertUniforms, fragUniforms [2]interface{}) ([2]*program, backend.InputLayout, error) {
var progs [2]*program
prog, err := b.NewProgram(vsSrc, fsSrc[materialTexture])
if err != nil {
return progs, nil, err
}
var vertBuffer *uniformBuffer
if u := vertUniforms[materialTexture]; u != nil {
vertBuffer = newUniformBuffer(b, u)
prog.SetVertexUniforms(vertBuffer.buf)
}
var fragBuffer *uniformBuffer
if u := fragUniforms[materialTexture]; u != nil {
fragBuffer = newUniformBuffer(b, u)
prog.SetFragmentUniforms(fragBuffer.buf)
}
progs[materialTexture] = newProgram(prog, vertBuffer, fragBuffer)
prog, err = b.NewProgram(vsSrc, fsSrc[materialColor])
if err != nil {
progs[materialTexture].Release()
return progs, nil, err
}
if u := vertUniforms[materialColor]; u != nil {
vertBuffer = newUniformBuffer(b, u)
prog.SetVertexUniforms(vertBuffer.buf)
}
if u := fragUniforms[materialColor]; u != nil {
fragBuffer = newUniformBuffer(b, u)
prog.SetFragmentUniforms(fragBuffer.buf)
}
progs[materialColor] = newProgram(prog, vertBuffer, fragBuffer)
layout, err := b.NewInputLayout(vsSrc, []backend.InputDesc{
{Type: backend.DataTypeFloat, Size: 2, Offset: 0},
{Type: backend.DataTypeFloat, Size: 2, Offset: 4 * 2},
})
if err != nil {
progs[materialTexture].Release()
progs[materialColor].Release()
return progs, nil, err
}
return progs, layout, nil
}
func (r *renderer) stencilClips(pathCache *opCache, ops []*pathOp) {
if len(r.packer.sizes) == 0 {
return
}
fbo := -1
r.pather.begin(r.packer.sizes)
for _, p := range ops {
if fbo != p.place.Idx {
fbo = p.place.Idx
f := r.pather.stenciler.cover(fbo)
r.ctx.BindFramebuffer(f.fbo)
r.ctx.Clear(0.0, 0.0, 0.0, 0.0)
}
v, _ := pathCache.get(p.pathKey)
r.pather.stencilPath(p.clip, p.off, p.place.Pos, v.data)
}
}
func (r *renderer) intersect(ops []imageOp) {
if len(r.intersections.sizes) == 0 {
return
}
fbo := -1
r.pather.stenciler.beginIntersect(r.intersections.sizes)
r.ctx.BindVertexBuffer(r.blitter.quadVerts, 4*4, 0)
r.ctx.BindInputLayout(r.pather.stenciler.iprog.layout)
for _, img := range ops {
if img.clipType != clipTypeIntersection {
continue
}
if fbo != img.place.Idx {
fbo = img.place.Idx
f := r.pather.stenciler.intersections.fbos[fbo]
r.ctx.BindFramebuffer(f.fbo)
r.ctx.Clear(1.0, 0.0, 0.0, 0.0)
}
r.ctx.Viewport(img.place.Pos.X, img.place.Pos.Y, img.clip.Dx(), img.clip.Dy())
r.intersectPath(img.path, img.clip)
}
}
func (r *renderer) intersectPath(p *pathOp, clip image.Rectangle) {
if p.parent != nil {
r.intersectPath(p.parent, clip)
}
if !p.path {
return
}
uv := image.Rectangle{
Min: p.place.Pos,
Max: p.place.Pos.Add(p.clip.Size()),
}
o := clip.Min.Sub(p.clip.Min)
sub := image.Rectangle{
Min: o,
Max: o.Add(clip.Size()),
}
fbo := r.pather.stenciler.cover(p.place.Idx)
r.ctx.BindTexture(0, fbo.tex)
coverScale, coverOff := texSpaceTransform(toRectF(uv), fbo.size)
subScale, subOff := texSpaceTransform(toRectF(sub), p.clip.Size())
r.pather.stenciler.iprog.uniforms.vert.uvTransform = [4]float32{coverScale.X, coverScale.Y, coverOff.X, coverOff.Y}
r.pather.stenciler.iprog.uniforms.vert.subUVTransform = [4]float32{subScale.X, subScale.Y, subOff.X, subOff.Y}
r.pather.stenciler.iprog.prog.UploadUniforms()
r.ctx.DrawArrays(backend.DrawModeTriangleStrip, 0, 4)
}
func (r *renderer) packIntersections(ops []imageOp) {
r.intersections.clear()
for i, img := range ops {
var npaths int
var onePath *pathOp
for p := img.path; p != nil; p = p.parent {
if p.path {
onePath = p
npaths++
}
}
switch npaths {
case 0:
case 1:
place := onePath.place
place.Pos = place.Pos.Sub(onePath.clip.Min).Add(img.clip.Min)
ops[i].place = place
ops[i].clipType = clipTypePath
default:
sz := image.Point{X: img.clip.Dx(), Y: img.clip.Dy()}
place, ok := r.intersections.add(sz)
if !ok {
panic("internal error: if the intersection fit, the intersection should fit as well")
}
ops[i].clipType = clipTypeIntersection
ops[i].place = place
}
}
}
func (r *renderer) packStencils(pops *[]*pathOp) {
r.packer.clear()
ops := *pops
// Allocate atlas space for cover textures.
var i int
for i < len(ops) {
p := ops[i]
if p.clip.Empty() {
ops[i] = ops[len(ops)-1]
ops = ops[:len(ops)-1]
continue
}
sz := image.Point{X: p.clip.Dx(), Y: p.clip.Dy()}
place, ok := r.packer.add(sz)
if !ok {
// The clip area is at most the entire screen. Hopefully no
// screen is larger than GL_MAX_TEXTURE_SIZE.
panic(fmt.Errorf("clip area %v is larger than maximum texture size %dx%d", p.clip, r.packer.maxDim, r.packer.maxDim))
}
p.place = place
i++
}
*pops = ops
}
// intersects intersects clip and b where b is offset by off.
// ceilRect returns a bounding image.Rectangle for a f32.Rectangle.
func boundRectF(r f32.Rectangle) image.Rectangle {
return image.Rectangle{
Min: image.Point{
X: int(floor(r.Min.X)),
Y: int(floor(r.Min.Y)),
},
Max: image.Point{
X: int(ceil(r.Max.X)),
Y: int(ceil(r.Max.Y)),
},
}
}
func toRectF(r image.Rectangle) f32.Rectangle {
return f32.Rectangle{
Min: f32.Point{
X: float32(r.Min.X),
Y: float32(r.Min.Y),
},
Max: f32.Point{
X: float32(r.Max.X),
Y: float32(r.Max.Y),
},
}
}
func ceil(v float32) int {
return int(math.Ceil(float64(v)))
}
func floor(v float32) int {
return int(math.Floor(float64(v)))
}
func (d *drawOps) reset(cache *resourceCache, viewport image.Point) {
d.profile = false
d.clearColor = f32color.RGBA{R: 1.0, G: 1.0, B: 1.0, A: 1.0}
d.cache = cache
d.viewport = viewport
d.imageOps = d.imageOps[:0]
d.zimageOps = d.zimageOps[:0]
d.pathOps = d.pathOps[:0]
d.pathOpCache = d.pathOpCache[:0]
d.vertCache = d.vertCache[:0]
}
func (d *drawOps) collect(cache *resourceCache, root *op.Ops, viewport image.Point) {
d.reset(cache, viewport)
clip := f32.Rectangle{
Max: f32.Point{X: float32(viewport.X), Y: float32(viewport.Y)},
}
d.reader.Reset(root)
state := drawState{
clip: clip,
rect: true,
color: color.RGBA{A: 0xff},
}
d.collectOps(&d.reader, state)
}
func (d *drawOps) newPathOp() *pathOp {
d.pathOpCache = append(d.pathOpCache, pathOp{})
return &d.pathOpCache[len(d.pathOpCache)-1]
}
func (d *drawOps) addClipPath(state *drawState, aux []byte, auxKey ops.Key, bounds f32.Rectangle, off f32.Point) {
npath := d.newPathOp()
*npath = pathOp{
parent: state.cpath,
bounds: bounds,
off: off,
}
state.cpath = npath
if len(aux) > 0 {
state.rect = false
state.cpath.pathKey = auxKey
state.cpath.path = true
state.cpath.pathVerts = aux
d.pathOps = append(d.pathOps, state.cpath)
}
}
// split a transform into two parts, one which is pur offset and the
// other representing the scaling, shearing and rotation part
func splitTransform(t f32.Affine2D) (srs f32.Affine2D, offset f32.Point) {
sx, hx, ox, hy, sy, oy := t.Elems()
offset = f32.Point{X: ox, Y: oy}
srs = f32.NewAffine2D(sx, hx, 0, hy, sy, 0)
return
}
func (d *drawOps) collectOps(r *ops.Reader, state drawState) int {
var aux []byte
var auxKey ops.Key
loop:
for encOp, ok := r.Decode(); ok; encOp, ok = r.Decode() {
switch opconst.OpType(encOp.Data[0]) {
case opconst.TypeProfile:
d.profile = true
case opconst.TypeTransform:
dop := ops.DecodeTransform(encOp.Data)
state.t = state.t.Mul(dop)
case opconst.TypeAux:
aux = encOp.Data[opconst.TypeAuxLen:]
auxKey = encOp.Key
case opconst.TypeClip:
var op clipOp
op.decode(encOp.Data)
bounds := op.bounds
trans, off := splitTransform(state.t)
if len(aux) > 0 {
// There is a clipping path, build the gpu data and update the
// cache key such that it will be equal only if the transform is the
// same also. Use cached data if we have it.
auxKey = auxKey.SetTransform(trans)
if v, ok := d.pathCache.get(auxKey); ok {
// Since the GPU data exists in the cache aux will not be used.
// Why is this not used for the offset shapes?
op.bounds = v.bounds
} else {
aux, op.bounds = d.buildVerts(aux, trans)
// add it to the cache, without GPU data, so the transform can be
// reused.
d.pathCache.put(auxKey, opCacheValue{bounds: op.bounds})
}
} else {
aux, op.bounds, _ = d.boundsForTransformedRect(bounds, trans)
auxKey = encOp.Key
auxKey.SetTransform(trans)
}
state.clip = state.clip.Intersect(op.bounds.Add(off))
d.addClipPath(&state, aux, auxKey, op.bounds, off)
aux = nil
auxKey = ops.Key{}
case opconst.TypeColor:
state.matType = materialColor
state.color = decodeColorOp(encOp.Data)
case opconst.TypeImage:
state.matType = materialTexture
state.image = decodeImageOp(encOp.Data, encOp.Refs)
case opconst.TypePaint:
op := decodePaintOp(encOp.Data)
// Transform (if needed) the painting rectangle and if so generate a clip path,
// for those cases also compute a partialTrans that maps texture coordinates between
// the new bounding rectangle and the transformed original paint rectangle.
trans, off := splitTransform(state.t)
clipData, bnd, partialTrans := d.boundsForTransformedRect(op.Rect, trans)
clip := state.clip.Intersect(bnd.Add(off))
if clip.Empty() {
continue
}
wasrect := state.rect
if clipData != nil {
// The paint operation is sheared or rotated, add a clip path representing
// this transformed rectangle.
encOp.Key.SetTransform(trans)
d.addClipPath(&state, clipData, encOp.Key, bnd, off)
}
bounds := boundRectF(clip)
mat := state.materialFor(d.cache, bnd, off, partialTrans, bounds)
if bounds.Min == (image.Point{}) && bounds.Max == d.viewport && state.rect && mat.opaque && mat.material == materialColor {
// The image is a uniform opaque color and takes up the whole screen.
// Scrap images up to and including this image and set clear color.
d.zimageOps = d.zimageOps[:0]
d.imageOps = d.imageOps[:0]
state.z = 0
d.clearColor = mat.color.Opaque()
continue
}
state.z++
if state.z != int(uint16(state.z)) {
// TODO(eliasnaur) gioui.org/issue/127.
panic("more than 65k paint objects not supported")
}
// Assume 16-bit depth buffer.
const zdepth = 1 << 16
// Convert z to window-space, assuming depth range [0;1].
zf := float32(state.z)*2/zdepth - 1.0
img := imageOp{
z: zf,
path: state.cpath,
off: off,
clip: bounds,
material: mat,
}
if state.rect && img.material.opaque {
d.zimageOps = append(d.zimageOps, img)
} else {
d.imageOps = append(d.imageOps, img)
}
if clipData != nil {
// we added a clip path that should not remain
state.cpath = state.cpath.parent
state.rect = wasrect
}
case opconst.TypePush:
state.z = d.collectOps(r, state)
case opconst.TypePop:
break loop
}
}
return state.z
}
func expandPathOp(p *pathOp, clip image.Rectangle) {
for p != nil {
pclip := p.clip
if !pclip.Empty() {
clip = clip.Union(pclip)
}
p.clip = clip
p = p.parent
}
}
func (d *drawState) materialFor(cache *resourceCache, rect f32.Rectangle, off f32.Point, trans f32.Affine2D, clip image.Rectangle) material {
var m material
switch d.matType {
case materialColor:
m.material = materialColor
m.color = f32color.RGBAFromSRGB(d.color)
m.opaque = m.color.A == 1.0
case materialTexture:
m.material = materialTexture
dr := boundRectF(rect.Add(off))
sz := d.image.src.Bounds().Size()
sr := layout.FRect(d.image.rect)
if dx := float32(dr.Dx()); dx != 0 {
// Don't clip 1 px width sources.
if sdx := sr.Dx(); sdx > 1 {
sr.Min.X += (float32(clip.Min.X-dr.Min.X)*sdx + dx/2) / dx
sr.Max.X -= (float32(dr.Max.X-clip.Max.X)*sdx + dx/2) / dx
}
}
if dy := float32(dr.Dy()); dy != 0 {
// Don't clip 1 px height sources.
if sdy := sr.Dy(); sdy > 1 {
sr.Min.Y += (float32(clip.Min.Y-dr.Min.Y)*sdy + dy/2) / dy
sr.Max.Y -= (float32(dr.Max.Y-clip.Max.Y)*sdy + dy/2) / dy
}
}
tex, exists := cache.get(d.image.handle)
if !exists {
t := &texture{
src: d.image.src,
}
cache.put(d.image.handle, t)
tex = t
}
m.texture = tex.(*texture)
uvScale, uvOffset := texSpaceTransform(sr, sz)
m.uvTrans = trans.Mul(f32.Affine2D{}.Scale(f32.Point{}, uvScale).Offset(uvOffset))
}
return m
}
func (r *renderer) drawZOps(ops []imageOp) {
r.ctx.SetDepthTest(true)
r.ctx.BindVertexBuffer(r.blitter.quadVerts, 4*4, 0)
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.ctx.BindTexture(0, r.texHandle(m.texture))
}
drc := img.clip
scale, off := clipSpaceTransform(drc, r.blitter.viewport)
r.blitter.blit(img.z, m.material, m.color, scale, off, m.uvTrans)
}
r.ctx.SetDepthTest(false)
}
func (r *renderer) drawOps(ops []imageOp) {
r.ctx.SetDepthTest(true)
r.ctx.DepthMask(false)
r.ctx.BlendFunc(backend.BlendFactorOne, backend.BlendFactorOneMinusSrcAlpha)
r.ctx.BindVertexBuffer(r.blitter.quadVerts, 4*4, 0)
r.ctx.BindInputLayout(r.pather.coverer.layout)
var coverTex backend.Texture
for _, img := range ops {
m := img.material
switch m.material {
case materialTexture:
r.ctx.BindTexture(0, r.texHandle(m.texture))
}
drc := img.clip
scale, off := clipSpaceTransform(drc, r.blitter.viewport)
var fbo stencilFBO
switch img.clipType {
case clipTypeNone:
r.blitter.blit(img.z, m.material, m.color, scale, off, m.uvTrans)
continue
case clipTypePath:
fbo = r.pather.stenciler.cover(img.place.Idx)
case clipTypeIntersection:
fbo = r.pather.stenciler.intersections.fbos[img.place.Idx]
}
if coverTex != fbo.tex {
coverTex = fbo.tex
r.ctx.BindTexture(1, coverTex)
}
uv := image.Rectangle{
Min: img.place.Pos,
Max: img.place.Pos.Add(drc.Size()),
}
coverScale, coverOff := texSpaceTransform(toRectF(uv), fbo.size)
r.pather.cover(img.z, m.material, m.color, scale, off, m.uvTrans, coverScale, coverOff)
}
r.ctx.DepthMask(true)
r.ctx.SetDepthTest(false)
}
func (b *blitter) blit(z float32, mat materialType, col f32color.RGBA, scale, off f32.Point, uvTrans f32.Affine2D) {
p := b.prog[mat]
b.ctx.BindProgram(p.prog)
var uniforms *blitUniforms
switch mat {
case materialColor:
b.colUniforms.frag.color = col
uniforms = &b.colUniforms.vert.blitUniforms
case materialTexture:
t1, t2, t3, t4, t5, t6 := uvTrans.Elems()
b.texUniforms.vert.blitUniforms.uvTransformR1 = [4]float32{t1, t2, t3, 0}
b.texUniforms.vert.blitUniforms.uvTransformR2 = [4]float32{t4, t5, t6, 0}
uniforms = &b.texUniforms.vert.blitUniforms
}
uniforms.z = z
uniforms.transform = [4]float32{scale.X, scale.Y, off.X, off.Y}
p.UploadUniforms()
b.ctx.DrawArrays(backend.DrawModeTriangleStrip, 0, 4)
}
// newUniformBuffer creates a new GPU uniform buffer backed by the
// structure uniformBlock points to.
func newUniformBuffer(b backend.Device, uniformBlock interface{}) *uniformBuffer {
ref := reflect.ValueOf(uniformBlock)
// Determine the size of the uniforms structure, *uniforms.
size := ref.Elem().Type().Size()
// Map the uniforms structure as a byte slice.
ptr := (*[1 << 30]byte)(unsafe.Pointer(ref.Pointer()))[:size:size]
ubuf, err := b.NewBuffer(backend.BufferBindingUniforms, len(ptr))
if err != nil {
panic(err)
}
return &uniformBuffer{buf: ubuf, ptr: ptr}
}
func (u *uniformBuffer) Upload() {
u.buf.Upload(u.ptr)
}
func (u *uniformBuffer) Release() {
u.buf.Release()
u.buf = nil
}
func newProgram(prog backend.Program, vertUniforms, fragUniforms *uniformBuffer) *program {
if vertUniforms != nil {
prog.SetVertexUniforms(vertUniforms.buf)
}
if fragUniforms != nil {
prog.SetFragmentUniforms(fragUniforms.buf)
}
return &program{prog: prog, vertUniforms: vertUniforms, fragUniforms: fragUniforms}
}
func (p *program) UploadUniforms() {
if p.vertUniforms != nil {
p.vertUniforms.Upload()
}
if p.fragUniforms != nil {
p.fragUniforms.Upload()
}
}
func (p *program) Release() {
p.prog.Release()
p.prog = nil
if p.vertUniforms != nil {
p.vertUniforms.Release()
p.vertUniforms = nil
}
if p.fragUniforms != nil {
p.fragUniforms.Release()
p.fragUniforms = nil
}
}
// texSpaceTransform return the scale and offset that transforms the given subimage
// into quad texture coordinates.
func texSpaceTransform(r f32.Rectangle, bounds image.Point) (f32.Point, f32.Point) {
size := f32.Point{X: float32(bounds.X), Y: float32(bounds.Y)}
scale := f32.Point{X: r.Dx() / size.X, Y: r.Dy() / size.Y}
offset := f32.Point{X: r.Min.X / size.X, Y: r.Min.Y / size.Y}
return scale, offset
}
// clipSpaceTransform returns the scale and offset that transforms the given
// rectangle from a viewport into OpenGL clip space.
func clipSpaceTransform(r image.Rectangle, viewport image.Point) (f32.Point, f32.Point) {
// First, transform UI coordinates to OpenGL coordinates:
//
// [(-1, +1) (+1, +1)]
// [(-1, -1) (+1, -1)]
//
x, y := float32(r.Min.X), float32(r.Min.Y)
w, h := float32(r.Dx()), float32(r.Dy())
vx, vy := 2/float32(viewport.X), 2/float32(viewport.Y)
x = x*vx - 1
y = 1 - y*vy
w *= vx
h *= vy
// Then, compute the transformation from the fullscreen quad to
// the rectangle at (x, y) and dimensions (w, h).
scale := f32.Point{X: w * .5, Y: h * .5}
offset := f32.Point{X: x + w*.5, Y: y - h*.5}
return scale, offset
}
// Fill in maximal Y coordinates of the NW and NE corners.
func fillMaxY(verts []byte) {
contour := 0
bo := binary.LittleEndian
for len(verts) > 0 {
maxy := float32(math.Inf(-1))
i := 0
for ; i+vertStride*4 <= len(verts); i += vertStride * 4 {
vert := verts[i : i+vertStride]
// MaxY contains the integer contour index.
pathContour := int(bo.Uint32(vert[int(unsafe.Offsetof(((*vertex)(nil)).MaxY)):]))
if contour != pathContour {
contour = pathContour
break
}
fromy := math.Float32frombits(bo.Uint32(vert[int(unsafe.Offsetof(((*vertex)(nil)).FromY)):]))
ctrly := math.Float32frombits(bo.Uint32(vert[int(unsafe.Offsetof(((*vertex)(nil)).CtrlY)):]))
toy := math.Float32frombits(bo.Uint32(vert[int(unsafe.Offsetof(((*vertex)(nil)).ToY)):]))
if fromy > maxy {
maxy = fromy
}
if ctrly > maxy {
maxy = ctrly
}
if toy > maxy {
maxy = toy
}
}
fillContourMaxY(maxy, verts[:i])
verts = verts[i:]
}
}
func fillContourMaxY(maxy float32, verts []byte) {
bo := binary.LittleEndian
for i := 0; i < len(verts); i += vertStride {
off := int(unsafe.Offsetof(((*vertex)(nil)).MaxY))
bo.PutUint32(verts[i+off:], math.Float32bits(maxy))
}
}
func (d *drawOps) writeVertCache(n int) []byte {
d.vertCache = append(d.vertCache, make([]byte, n)...)
return d.vertCache[len(d.vertCache)-n:]
}
// transform, split paths as needed, calculate maxY, bounds and create GPU vertices.
func (d *drawOps) buildVerts(aux []byte, tr f32.Affine2D) (verts []byte, bounds f32.Rectangle) {
inf := float32(math.Inf(+1))
d.qs.bounds = f32.Rectangle{
Min: f32.Point{X: inf, Y: inf},
Max: f32.Point{X: -inf, Y: -inf},
}
d.qs.d = d
bo := binary.LittleEndian
startLength := len(d.vertCache)
for qi := 0; len(aux) >= (ops.QuadSize + 4); qi++ {
d.qs.contour = bo.Uint32(aux)
quad := ops.DecodeQuad(aux[4:])
quad = quad.Transform(tr)
d.qs.splitAndEncode(quad)
aux = aux[ops.QuadSize+4:]
}
fillMaxY(d.vertCache[startLength:])
return d.vertCache[startLength:], d.qs.bounds
}
// create GPU vertices for transformed r, find the bounds and establish texture transform.
func (d *drawOps) boundsForTransformedRect(r f32.Rectangle, tr f32.Affine2D) (aux []byte, bnd f32.Rectangle, ptr f32.Affine2D) {
if isPureOffset(tr) {
// fast-path to allow blitting of pure rectangles
_, _, ox, _, _, oy := tr.Elems()
off := f32.Pt(ox, oy)
bnd.Min = r.Min.Add(off)
bnd.Max = r.Max.Add(off)
return
}
// transform all corners, find new bounds
corners := [4]f32.Point{
tr.Transform(r.Min), tr.Transform(f32.Pt(r.Max.X, r.Min.Y)),
tr.Transform(r.Max), tr.Transform(f32.Pt(r.Min.X, r.Max.Y)),
}
bnd.Min = f32.Pt(math.MaxFloat32, math.MaxFloat32)
bnd.Max = f32.Pt(-math.MaxFloat32, -math.MaxFloat32)
for _, c := range corners {
if c.X < bnd.Min.X {
bnd.Min.X = c.X
}
if c.Y < bnd.Min.Y {
bnd.Min.Y = c.Y
}
if c.X > bnd.Max.X {
bnd.Max.X = c.X
}
if c.Y > bnd.Max.Y {
bnd.Max.Y = c.Y
}
}
// build the GPU vertices
l := len(d.vertCache)
d.vertCache = append(d.vertCache, make([]byte, vertStride*4*4)...)
aux = d.vertCache[l:]
encodeQuadTo(aux, 0, corners[0], corners[0].Add(corners[1]).Mul(0.5), corners[1])
encodeQuadTo(aux[vertStride*4:], 0, corners[1], corners[1].Add(corners[2]).Mul(0.5), corners[2])
encodeQuadTo(aux[vertStride*4*2:], 0, corners[2], corners[2].Add(corners[3]).Mul(0.5), corners[3])
encodeQuadTo(aux[vertStride*4*3:], 0, corners[3], corners[3].Add(corners[0]).Mul(0.5), corners[0])
fillMaxY(aux)
// establish the transform mapping from bounds rectangle to transformed corners
var P1, P2, P3 f32.Point
P1.X = (corners[1].X - bnd.Min.X) / (bnd.Max.X - bnd.Min.X)
P1.Y = (corners[1].Y - bnd.Min.Y) / (bnd.Max.Y - bnd.Min.Y)
P2.X = (corners[2].X - bnd.Min.X) / (bnd.Max.X - bnd.Min.X)
P2.Y = (corners[2].Y - bnd.Min.Y) / (bnd.Max.Y - bnd.Min.Y)
P3.X = (corners[3].X - bnd.Min.X) / (bnd.Max.X - bnd.Min.X)
P3.Y = (corners[3].Y - bnd.Min.Y) / (bnd.Max.Y - bnd.Min.Y)
sx, sy := P2.X-P3.X, P2.Y-P3.Y
ptr = f32.NewAffine2D(sx, P2.X-P1.X, P1.X-sx, sy, P2.Y-P1.Y, P1.Y-sy).Invert()
return
}
func isPureOffset(t f32.Affine2D) bool {
a, b, _, d, e, _ := t.Elems()
return a == 1 && b == 0 && d == 0 && e == 1
}