added a blurred fill style in backend, used it for blurred shadow drawing
This commit is contained in:
Thomas Friedel
parent
c5c8ac500f
commit
c28c50a22e
6 changed files with 165 additions and 88 deletions
|
|
@ -6,5 +6,4 @@ type Backend interface {
|
|||
ClearRect(x, y, w, h int)
|
||||
Clear(pts [4][2]float64)
|
||||
Fill(style *backendbase.Style, pts [][2]float64)
|
||||
// BlurredShadow(shadow *backendbase.Shadow, pts [][2]float64)
|
||||
}
|
||||
|
|
|
|||
|
|
@ -5,14 +5,8 @@ import "image/color"
|
|||
type Style struct {
|
||||
Color color.RGBA
|
||||
GlobalAlpha float64
|
||||
Blur float64
|
||||
// radialGradient *RadialGradient
|
||||
// linearGradient *LinearGradient
|
||||
// image *Image
|
||||
}
|
||||
|
||||
type Shadow struct {
|
||||
Color color.RGBA
|
||||
OffsetX float64
|
||||
OffsetY float64
|
||||
Blur float64
|
||||
}
|
||||
|
|
|
|||
|
|
@ -1,56 +1,13 @@
|
|||
package goglbackend
|
||||
|
||||
import (
|
||||
"math"
|
||||
"unsafe"
|
||||
|
||||
"github.com/go-gl/gl/v3.2-core/gl"
|
||||
"github.com/tfriedel6/canvas/backend/backendbase"
|
||||
)
|
||||
|
||||
/*
|
||||
// FillRect fills a rectangle with the active fill style
|
||||
func (b *GoGLBackend) FillRect(x, y, w, h float64) {
|
||||
cv.activate()
|
||||
|
||||
p0 := cv.tf(vec{x, y})
|
||||
p1 := cv.tf(vec{x, y + h})
|
||||
p2 := cv.tf(vec{x + w, y + h})
|
||||
p3 := cv.tf(vec{x + w, y})
|
||||
|
||||
if cv.state.shadowColor.a != 0 {
|
||||
tris := [24]float32{
|
||||
0, 0,
|
||||
float32(cv.fw), 0,
|
||||
float32(cv.fw), float32(cv.fh),
|
||||
0, 0,
|
||||
float32(cv.fw), float32(cv.fh),
|
||||
0, float32(cv.fh),
|
||||
float32(p0[0]), float32(p0[1]),
|
||||
float32(p3[0]), float32(p3[1]),
|
||||
float32(p2[0]), float32(p2[1]),
|
||||
float32(p0[0]), float32(p0[1]),
|
||||
float32(p2[0]), float32(p2[1]),
|
||||
float32(p1[0]), float32(p1[1]),
|
||||
}
|
||||
cv.drawShadow(tris[:])
|
||||
}
|
||||
|
||||
gl.BindBuffer(gl.ARRAY_BUFFER, buf)
|
||||
data := [8]float32{float32(p0[0]), float32(p0[1]), float32(p1[0]), float32(p1[1]), float32(p2[0]), float32(p2[1]), float32(p3[0]), float32(p3[1])}
|
||||
gl.BufferData(gl.ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl.STREAM_DRAW)
|
||||
|
||||
gl.StencilFunc(gl.EQUAL, 0, 0xFF)
|
||||
|
||||
vertex := cv.useShader(&cv.state.fill)
|
||||
gl.VertexAttribPointer(vertex, 2, gl.FLOAT, false, 0, 0)
|
||||
gl.EnableVertexAttribArray(vertex)
|
||||
gl.DrawArrays(gl.TRIANGLE_FAN, 0, 4)
|
||||
gl.DisableVertexAttribArray(vertex)
|
||||
|
||||
gl.StencilFunc(gl.ALWAYS, 0, 0xFF)
|
||||
}
|
||||
*/
|
||||
|
||||
// ClearRect sets the color of the rectangle to transparent black
|
||||
func (b *GoGLBackend) ClearRect(x, y, w, h int) {
|
||||
gl.Scissor(int32(x), int32(b.h-y-h), int32(w), int32(h))
|
||||
|
|
@ -88,29 +45,14 @@ func (b *GoGLBackend) Clear(pts [4][2]float64) {
|
|||
gl.Enable(gl.BLEND)
|
||||
}
|
||||
|
||||
/*
|
||||
func (b *GoGLBackend) Fill(style *backendbase.Style, pts [4][2]float64) {
|
||||
gl.BindBuffer(gl.ARRAY_BUFFER, b.buf)
|
||||
data := [8]float32{
|
||||
float32(pts[0][0]), float32(pts[0][1]),
|
||||
float32(pts[1][0]), float32(pts[1][1]),
|
||||
float32(pts[2][0]), float32(pts[2][1]),
|
||||
float32(pts[3][0]), float32(pts[3][1])}
|
||||
gl.BufferData(gl.ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl.STREAM_DRAW)
|
||||
|
||||
gl.StencilFunc(gl.EQUAL, 0, 0xFF)
|
||||
|
||||
vertex := b.useShader(style)
|
||||
gl.VertexAttribPointer(vertex, 2, gl.FLOAT, false, 0, nil)
|
||||
gl.EnableVertexAttribArray(vertex)
|
||||
gl.DrawArrays(gl.TRIANGLE_FAN, 0, 4)
|
||||
gl.DisableVertexAttribArray(vertex)
|
||||
|
||||
gl.StencilFunc(gl.ALWAYS, 0, 0xFF)
|
||||
}
|
||||
*/
|
||||
|
||||
func (b *GoGLBackend) Fill(style *backendbase.Style, pts [][2]float64) {
|
||||
if style.Blur > 0 {
|
||||
b.offscr1.alpha = true
|
||||
b.enableTextureRenderTarget(&b.offscr1)
|
||||
gl.ClearColor(0, 0, 0, 0)
|
||||
gl.Clear(gl.COLOR_BUFFER_BIT | gl.STENCIL_BUFFER_BIT)
|
||||
}
|
||||
|
||||
b.ptsBuf = b.ptsBuf[:0]
|
||||
b.ptsBuf = append(b.ptsBuf,
|
||||
0, 0,
|
||||
|
|
@ -169,4 +111,107 @@ func (b *GoGLBackend) Fill(style *backendbase.Style, pts [][2]float64) {
|
|||
gl.Clear(gl.STENCIL_BUFFER_BIT)
|
||||
gl.StencilMask(0xFF)
|
||||
}
|
||||
|
||||
if style.Blur > 0 {
|
||||
b.drawBlurred(style.Blur)
|
||||
}
|
||||
}
|
||||
|
||||
func (b *GoGLBackend) drawBlurred(blur float64) {
|
||||
gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
|
||||
|
||||
var kernel []float32
|
||||
var kernelBuf [255]float32
|
||||
var gs *gaussianShader
|
||||
if blur < 3 {
|
||||
gs = &b.gauss15r
|
||||
kernel = kernelBuf[:15]
|
||||
} else if blur < 12 {
|
||||
gs = &b.gauss63r
|
||||
kernel = kernelBuf[:63]
|
||||
} else {
|
||||
gs = &b.gauss127r
|
||||
kernel = kernelBuf[:127]
|
||||
}
|
||||
|
||||
gaussianKernel(blur, kernel)
|
||||
|
||||
b.offscr2.alpha = true
|
||||
b.enableTextureRenderTarget(&b.offscr2)
|
||||
gl.ClearColor(0, 0, 0, 0)
|
||||
gl.Clear(gl.COLOR_BUFFER_BIT | gl.STENCIL_BUFFER_BIT)
|
||||
|
||||
gl.StencilFunc(gl.EQUAL, 0, 0xFF)
|
||||
|
||||
gl.BindBuffer(gl.ARRAY_BUFFER, b.shadowBuf)
|
||||
data := [16]float32{0, 0, 0, float32(b.h), float32(b.w), float32(b.h), float32(b.w), 0, 0, 0, 0, 1, 1, 1, 1, 0}
|
||||
gl.BufferData(gl.ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl.STREAM_DRAW)
|
||||
|
||||
gl.ActiveTexture(gl.TEXTURE0)
|
||||
gl.BindTexture(gl.TEXTURE_2D, b.offscr1.tex)
|
||||
|
||||
gl.UseProgram(gs.ID)
|
||||
gl.Uniform1i(gs.Image, 0)
|
||||
gl.Uniform2f(gs.CanvasSize, float32(b.fw), float32(b.fh))
|
||||
gl.Uniform2f(gs.KernelScale, 1.0/float32(b.fw), 0.0)
|
||||
gl.Uniform1fv(gs.Kernel, int32(len(kernel)), &kernel[0])
|
||||
gl.VertexAttribPointer(gs.Vertex, 2, gl.FLOAT, false, 0, nil)
|
||||
gl.VertexAttribPointer(gs.TexCoord, 2, gl.FLOAT, false, 0, gl.PtrOffset(8*4))
|
||||
gl.EnableVertexAttribArray(gs.Vertex)
|
||||
gl.EnableVertexAttribArray(gs.TexCoord)
|
||||
gl.DrawArrays(gl.TRIANGLE_FAN, 0, 4)
|
||||
gl.DisableVertexAttribArray(gs.Vertex)
|
||||
gl.DisableVertexAttribArray(gs.TexCoord)
|
||||
|
||||
gl.StencilFunc(gl.ALWAYS, 0, 0xFF)
|
||||
|
||||
b.disableTextureRenderTarget()
|
||||
|
||||
gl.StencilFunc(gl.EQUAL, 0, 0xFF)
|
||||
|
||||
gl.BindBuffer(gl.ARRAY_BUFFER, b.shadowBuf)
|
||||
data = [16]float32{0, 0, 0, float32(b.h), float32(b.w), float32(b.h), float32(b.w), 0, 0, 0, 0, 1, 1, 1, 1, 0}
|
||||
gl.BufferData(gl.ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl.STREAM_DRAW)
|
||||
|
||||
gl.ActiveTexture(gl.TEXTURE0)
|
||||
gl.BindTexture(gl.TEXTURE_2D, b.offscr2.tex)
|
||||
|
||||
gl.UseProgram(gs.ID)
|
||||
gl.Uniform1i(gs.Image, 0)
|
||||
gl.Uniform2f(gs.CanvasSize, float32(b.fw), float32(b.fh))
|
||||
gl.Uniform2f(gs.KernelScale, 0.0, 1.0/float32(b.fh))
|
||||
gl.Uniform1fv(gs.Kernel, int32(len(kernel)), &kernel[0])
|
||||
gl.VertexAttribPointer(gs.Vertex, 2, gl.FLOAT, false, 0, nil)
|
||||
gl.VertexAttribPointer(gs.TexCoord, 2, gl.FLOAT, false, 0, gl.PtrOffset(8*4))
|
||||
gl.EnableVertexAttribArray(gs.Vertex)
|
||||
gl.EnableVertexAttribArray(gs.TexCoord)
|
||||
gl.DrawArrays(gl.TRIANGLE_FAN, 0, 4)
|
||||
gl.DisableVertexAttribArray(gs.Vertex)
|
||||
gl.DisableVertexAttribArray(gs.TexCoord)
|
||||
|
||||
gl.StencilFunc(gl.ALWAYS, 0, 0xFF)
|
||||
|
||||
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
|
||||
}
|
||||
|
||||
func gaussianKernel(stddev float64, target []float32) {
|
||||
stddevSqr := stddev * stddev
|
||||
center := float64(len(target) / 2)
|
||||
factor := 1.0 / math.Sqrt(2*math.Pi*stddevSqr)
|
||||
for i := range target {
|
||||
x := float64(i) - center
|
||||
target[i] = float32(factor * math.Pow(math.E, -x*x/(2*stddevSqr)))
|
||||
}
|
||||
// normalizeKernel(target)
|
||||
}
|
||||
|
||||
func normalizeKernel(kernel []float32) {
|
||||
var sum float32
|
||||
for _, v := range kernel {
|
||||
sum += v
|
||||
}
|
||||
factor := 1.0 / sum
|
||||
for i := range kernel {
|
||||
kernel[i] *= factor
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -365,3 +365,54 @@ func (b *GoGLBackend) useAlphaShader(style *backendbase.Style, alphaTexSlot int3
|
|||
gl.Uniform1f(b.sar.GlobalAlpha, float32(style.GlobalAlpha))
|
||||
return b.sar.Vertex, b.sar.AlphaTexCoord
|
||||
}
|
||||
|
||||
func (b *GoGLBackend) enableTextureRenderTarget(offscr *offscreenBuffer) {
|
||||
if offscr.w != b.w || offscr.h != b.h {
|
||||
if offscr.w != 0 && offscr.h != 0 {
|
||||
gl.DeleteTextures(1, &offscr.tex)
|
||||
gl.DeleteFramebuffers(1, &offscr.frameBuf)
|
||||
gl.DeleteRenderbuffers(1, &offscr.renderStencilBuf)
|
||||
}
|
||||
offscr.w = b.w
|
||||
offscr.h = b.h
|
||||
|
||||
gl.ActiveTexture(gl.TEXTURE0)
|
||||
gl.GenTextures(1, &offscr.tex)
|
||||
gl.BindTexture(gl.TEXTURE_2D, offscr.tex)
|
||||
// todo do non-power-of-two textures work everywhere?
|
||||
if offscr.alpha {
|
||||
gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, int32(b.w), int32(b.h), 0, gl.RGBA, gl.UNSIGNED_BYTE, nil)
|
||||
} else {
|
||||
gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGB, int32(b.w), int32(b.h), 0, gl.RGB, gl.UNSIGNED_BYTE, nil)
|
||||
}
|
||||
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
|
||||
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
|
||||
|
||||
gl.GenFramebuffers(1, &offscr.frameBuf)
|
||||
gl.BindFramebuffer(gl.FRAMEBUFFER, offscr.frameBuf)
|
||||
|
||||
gl.GenRenderbuffers(1, &offscr.renderStencilBuf)
|
||||
gl.BindRenderbuffer(gl.RENDERBUFFER, offscr.renderStencilBuf)
|
||||
gl.RenderbufferStorage(gl.RENDERBUFFER, gl.DEPTH24_STENCIL8, int32(b.w), int32(b.h))
|
||||
gl.FramebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.RENDERBUFFER, offscr.renderStencilBuf)
|
||||
|
||||
gl.FramebufferTexture(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, offscr.tex, 0)
|
||||
|
||||
if err := gl.CheckFramebufferStatus(gl.FRAMEBUFFER); err != gl.FRAMEBUFFER_COMPLETE {
|
||||
// todo this should maybe not panic
|
||||
panic(fmt.Sprintf("Failed to set up framebuffer for offscreen texture: %x", err))
|
||||
}
|
||||
|
||||
gl.Clear(gl.COLOR_BUFFER_BIT | gl.STENCIL_BUFFER_BIT)
|
||||
} else {
|
||||
gl.BindFramebuffer(gl.FRAMEBUFFER, offscr.frameBuf)
|
||||
}
|
||||
}
|
||||
|
||||
func (b *GoGLBackend) disableTextureRenderTarget() {
|
||||
// if b.offscreen {
|
||||
// b.enableTextureRenderTarget(&b.offscrBuf)
|
||||
// } else {
|
||||
gl.BindFramebuffer(gl.FRAMEBUFFER, 0)
|
||||
// }
|
||||
}
|
||||
|
|
|
|||
|
|
@ -502,15 +502,6 @@ func (cv *Canvas) backendStyle(s *drawStyle, alpha float64) backendbase.Style {
|
|||
}
|
||||
}
|
||||
|
||||
func (cv *Canvas) backendShadow() backendbase.Shadow {
|
||||
return backendbase.Shadow{
|
||||
Color: cv.state.shadowColor,
|
||||
OffsetX: cv.state.shadowOffsetX,
|
||||
OffsetY: cv.state.shadowOffsetY,
|
||||
Blur: cv.state.shadowBlur,
|
||||
}
|
||||
}
|
||||
|
||||
func (cv *Canvas) useShader(style *drawStyle) (vertexLoc uint32) {
|
||||
if lg := style.linearGradient; lg != nil {
|
||||
lg.load()
|
||||
|
|
|
|||
|
|
@ -28,11 +28,8 @@ func (cv *Canvas) drawShadow2(pts [][2]float64) {
|
|||
})
|
||||
}
|
||||
|
||||
shadow := cv.backendShadow()
|
||||
if cv.state.shadowBlur == 0 {
|
||||
style := backendbase.Style{Color: shadow.Color, GlobalAlpha: 1}
|
||||
style := backendbase.Style{Color: cv.state.shadowColor, GlobalAlpha: 1, Blur: cv.state.shadowBlur}
|
||||
cv.b.Fill(&style, cv.shadowBuf)
|
||||
}
|
||||
}
|
||||
|
||||
func (cv *Canvas) drawShadow(tris []float32) {
|
||||
|
|
|
|||
Loading…
Reference in a new issue