text shadow rendering moved to backend
This commit is contained in:
Thomas Friedel
parent
43f040f777
commit
e7d0b1a7ee
8 changed files with 29 additions and 233 deletions
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@ -18,7 +18,7 @@ type Backend interface {
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Clear(pts [4][2]float64)
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Fill(style *FillStyle, pts [][2]float64)
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DrawImage(dimg Image, sx, sy, sw, sh, dx, dy, dw, dh float64, alpha float64)
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FillImageMask(style *FillStyle, mask *image.Alpha, pts [4][2]float64)
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FillImageMask(style *FillStyle, mask *image.Alpha, pts [][2]float64) // pts must have four points
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}
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// FillStyle is the color and other details on how to fill
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@ -118,7 +118,7 @@ func (b *GoGLBackend) Fill(style *backendbase.FillStyle, pts [][2]float64) {
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}
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}
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func (b *GoGLBackend) FillImageMask(style *backendbase.FillStyle, mask *image.Alpha, pts [4][2]float64) {
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func (b *GoGLBackend) FillImageMask(style *backendbase.FillStyle, mask *image.Alpha, pts [][2]float64) {
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w, h := mask.Rect.Dx(), mask.Rect.Dy()
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gl.ActiveTexture(gl.TEXTURE1)
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@ -128,7 +128,12 @@ func (b *GoGLBackend) FillImageMask(style *backendbase.FillStyle, mask *image.Al
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gl.TexSubImage2D(gl.TEXTURE_2D, 0, 0, int32(alphaTexSize-1-y), int32(w), 1, gl.ALPHA, gl.UNSIGNED_BYTE, gl.Ptr(&mask.Pix[off]))
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}
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// b.drawTextShadow(textOffset, w, h, x, y)
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if style.Blur > 0 {
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b.offscr1.alpha = true
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b.enableTextureRenderTarget(&b.offscr1)
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gl.ClearColor(0, 0, 0, 0)
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gl.Clear(gl.COLOR_BUFFER_BIT | gl.STENCIL_BUFFER_BIT)
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}
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gl.StencilFunc(gl.EQUAL, 0, 0xFF)
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@ -167,6 +172,10 @@ func (b *GoGLBackend) FillImageMask(style *backendbase.FillStyle, mask *image.Al
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}
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gl.ActiveTexture(gl.TEXTURE0)
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if style.Blur > 0 {
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b.drawBlurred(style.Blur)
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}
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}
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func (b *GoGLBackend) drawBlurred(blur float64) {
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@ -225,7 +225,7 @@ func glError() error {
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// needs to be called if any other GL code changes the viewport
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func (b *GoGLBackend) Activate() {
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// if b.offscreen {
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// gli.Viewport(0, 0, int32(cv.w), int32(cv.h))
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// gl.Viewport(0, 0, int32(cv.w), int32(cv.h))
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// cv.enableTextureRenderTarget(&cv.offscrBuf)
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// cv.offscrImg.w = cv.offscrBuf.w
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// cv.offscrImg.h = cv.offscrBuf.h
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69
canvas.go
69
canvas.go
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@ -519,75 +519,6 @@ func (cv *Canvas) backendFillStyle(s *drawStyle, alpha float64) backendbase.Fill
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return stl
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}
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func (cv *Canvas) useAlphaShader(style *drawStyle, alphaTexSlot int32) (vertexLoc, alphaTexCoordLoc uint32) {
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if lg := style.linearGradient; lg != nil {
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lg.load()
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// gli.ActiveTexture(gl_TEXTURE0)
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// gli.BindTexture(gl_TEXTURE_2D, lg.tex)
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// gli.UseProgram(lgar.id)
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// from := cv.tf(lg.from)
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// to := cv.tf(lg.to)
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// dir := to.sub(from)
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// length := dir.len()
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// dir = dir.divf(length)
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// gli.Uniform2f(lgar.canvasSize, float32(cv.fw), float32(cv.fh))
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// inv := cv.state.transform.invert().f32()
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// gli.UniformMatrix3fv(lgar.invmat, 1, false, &inv[0])
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// gli.Uniform2f(lgar.from, float32(from[0]), float32(from[1]))
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// gli.Uniform2f(lgar.dir, float32(dir[0]), float32(dir[1]))
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// gli.Uniform1f(lgar.len, float32(length))
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// gli.Uniform1i(lgar.gradient, 0)
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// gli.Uniform1i(lgar.alphaTex, alphaTexSlot)
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// gli.Uniform1f(lgar.globalAlpha, float32(cv.state.globalAlpha))
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// return lgar.vertex, lgar.alphaTexCoord
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}
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if rg := style.radialGradient; rg != nil {
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rg.load()
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// gli.ActiveTexture(gl_TEXTURE0)
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// gli.BindTexture(gl_TEXTURE_2D, rg.tex)
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// gli.UseProgram(rgar.id)
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// from := cv.tf(rg.from)
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// to := cv.tf(rg.to)
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// dir := to.sub(from)
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// length := dir.len()
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// dir = dir.divf(length)
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// gli.Uniform2f(rgar.canvasSize, float32(cv.fw), float32(cv.fh))
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// inv := cv.state.transform.invert().f32()
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// gli.UniformMatrix3fv(rgar.invmat, 1, false, &inv[0])
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// gli.Uniform2f(rgar.from, float32(from[0]), float32(from[1]))
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// gli.Uniform2f(rgar.to, float32(to[0]), float32(to[1]))
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// gli.Uniform2f(rgar.dir, float32(dir[0]), float32(dir[1]))
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// gli.Uniform1f(rgar.radFrom, float32(rg.radFrom))
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// gli.Uniform1f(rgar.radTo, float32(rg.radTo))
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// gli.Uniform1f(rgar.len, float32(length))
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// gli.Uniform1i(rgar.gradient, 0)
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// gli.Uniform1i(rgar.alphaTex, alphaTexSlot)
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// gli.Uniform1f(rgar.globalAlpha, float32(cv.state.globalAlpha))
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// return rgar.vertex, rgar.alphaTexCoord
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}
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// if img := style.image; img != nil {
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// gli.UseProgram(ipar.id)
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// gli.ActiveTexture(gl_TEXTURE0)
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// gli.BindTexture(gl_TEXTURE_2D, img.tex)
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// gli.Uniform2f(ipar.canvasSize, float32(cv.fw), float32(cv.fh))
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// inv := cv.state.transform.invert().f32()
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// gli.UniformMatrix3fv(ipar.invmat, 1, false, &inv[0])
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// gli.Uniform2f(ipar.imageSize, float32(img.w), float32(img.h))
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// gli.Uniform1i(ipar.image, 0)
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// gli.Uniform1i(ipar.alphaTex, alphaTexSlot)
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// gli.Uniform1f(ipar.globalAlpha, float32(cv.state.globalAlpha))
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// return ipar.vertex, ipar.alphaTexCoord
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// }
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gli.UseProgram(sar.id)
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gli.Uniform2f(sar.canvasSize, float32(cv.fw), float32(cv.fh))
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c := colorGoToGL(style.color)
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gli.Uniform4f(sar.color, float32(c.r), float32(c.g), float32(c.b), float32(c.a))
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gli.Uniform1i(sar.alphaTex, alphaTexSlot)
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gli.Uniform1f(sar.globalAlpha, float32(cv.state.globalAlpha))
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return sar.vertex, sar.alphaTexCoord
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}
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func (cv *Canvas) enableTextureRenderTarget(offscr *offscreenBuffer) {
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if offscr.w != cv.w || offscr.h != cv.h {
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if offscr.w != 0 && offscr.h != 0 {
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@ -168,7 +168,7 @@ func (cv *Canvas) DrawImage(image interface{}, coords ...float64) {
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data[2] = cv.tf(vec{dx + dw, dy + dh})
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data[3] = cv.tf(vec{dx + dw, dy})
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cv.drawShadow2(data[:])
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cv.drawShadow2(data[:], nil)
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cv.b.DrawImage(img.img, sx, sy, sw, sh, dx, dy, dw, dh, cv.state.globalAlpha)
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}
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6
paths.go
6
paths.go
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@ -156,7 +156,7 @@ func (cv *Canvas) strokePath(path *Path2D) {
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start = false
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}
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cv.drawShadow2(tris)
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cv.drawShadow2(tris, nil)
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stl := cv.backendFillStyle(&cv.state.stroke, 1)
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cv.b.Fill(&stl, tris)
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@ -350,7 +350,7 @@ func (cv *Canvas) FillPath(path *Path2D) {
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return
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}
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cv.drawShadow2(tris)
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cv.drawShadow2(tris, nil)
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stl := cv.backendFillStyle(&cv.state.fill, 1)
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cv.b.Fill(&stl, tris)
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@ -526,7 +526,7 @@ func (cv *Canvas) FillRect(x, y, w, h float64) {
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data := [4][2]float64{{p0[0], p0[1]}, {p1[0], p1[1]}, {p2[0], p2[1]}, {p3[0], p3[1]}}
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cv.drawShadow2(data[:])
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cv.drawShadow2(data[:], nil)
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stl := cv.backendFillStyle(&cv.state.fill, 1)
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cv.b.Fill(&stl, data[:])
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160
shadows.go
160
shadows.go
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@ -2,13 +2,11 @@ package canvas
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import (
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"image"
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"math"
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"unsafe"
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"github.com/tfriedel6/canvas/backend/backendbase"
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)
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func (cv *Canvas) drawShadow2(pts [][2]float64) {
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func (cv *Canvas) drawShadow2(pts [][2]float64, mask *image.Alpha) {
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if cv.state.shadowColor.A == 0 {
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return
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}
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@ -29,158 +27,12 @@ func (cv *Canvas) drawShadow2(pts [][2]float64) {
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}
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style := backendbase.FillStyle{Color: cv.state.shadowColor, Blur: cv.state.shadowBlur}
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cv.b.Fill(&style, cv.shadowBuf)
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}
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func (cv *Canvas) drawTextShadow(offset image.Point, strWidth, strHeight int, x, y float64) {
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if cv.state.shadowColor.A == 0 {
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return
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if mask != nil {
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if len(cv.shadowBuf) != 4 {
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panic("invalid number of points to fill with mask, must be 4")
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}
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x += cv.state.shadowOffsetX
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y += cv.state.shadowOffsetY
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if cv.state.shadowBlur > 0 {
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offscr1.alpha = true
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cv.enableTextureRenderTarget(&offscr1)
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gli.ClearColor(0, 0, 0, 0)
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gli.Clear(gl_COLOR_BUFFER_BIT | gl_STENCIL_BUFFER_BIT)
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}
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gli.StencilFunc(gl_EQUAL, 0, 0xFF)
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gli.BindBuffer(gl_ARRAY_BUFFER, buf)
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var style drawStyle
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style.color = cv.state.shadowColor
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vertex, alphaTexCoord := cv.useAlphaShader(&style, 1)
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gli.EnableVertexAttribArray(vertex)
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gli.EnableVertexAttribArray(alphaTexCoord)
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p0 := cv.tf(vec{float64(offset.X) + x, float64(offset.Y) + y})
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p1 := cv.tf(vec{float64(offset.X) + x, float64(offset.Y+strHeight) + y})
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p2 := cv.tf(vec{float64(offset.X+strWidth) + x, float64(offset.Y+strHeight) + y})
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p3 := cv.tf(vec{float64(offset.X+strWidth) + x, float64(offset.Y) + y})
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tw := float64(strWidth) / alphaTexSize
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th := float64(strHeight) / alphaTexSize
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data := [16]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]),
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0, 1, 0, float32(1 - th), float32(tw), float32(1 - th), float32(tw), 1}
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gli.BufferData(gl_ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl_STREAM_DRAW)
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gli.VertexAttribPointer(vertex, 2, gl_FLOAT, false, 0, 0)
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gli.VertexAttribPointer(alphaTexCoord, 2, gl_FLOAT, false, 0, 8*4)
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gli.DrawArrays(gl_TRIANGLE_FAN, 0, 4)
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gli.DisableVertexAttribArray(vertex)
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gli.DisableVertexAttribArray(alphaTexCoord)
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gli.ActiveTexture(gl_TEXTURE0)
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gli.StencilFunc(gl_ALWAYS, 0, 0xFF)
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if cv.state.shadowBlur > 0 {
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cv.drawBlurredShadow()
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}
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}
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func (cv *Canvas) drawBlurredShadow() {
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gli.BlendFunc(gl_ONE, gl_ONE_MINUS_SRC_ALPHA)
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var kernel []float32
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var kernelBuf [255]float32
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var gs *gaussianShader
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if cv.state.shadowBlur < 3 {
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gs = gauss15r
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kernel = kernelBuf[:15]
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} else if cv.state.shadowBlur < 12 {
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gs = gauss63r
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kernel = kernelBuf[:63]
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cv.b.FillImageMask(&style, mask, cv.shadowBuf)
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} else {
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gs = gauss127r
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kernel = kernelBuf[:127]
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}
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gaussianKernel(cv.state.shadowBlur, kernel)
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offscr2.alpha = true
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cv.enableTextureRenderTarget(&offscr2)
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gli.ClearColor(0, 0, 0, 0)
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gli.Clear(gl_COLOR_BUFFER_BIT | gl_STENCIL_BUFFER_BIT)
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gli.StencilFunc(gl_EQUAL, 0, 0xFF)
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gli.BindBuffer(gl_ARRAY_BUFFER, shadowBuf)
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data := [16]float32{0, 0, 0, float32(cv.h), float32(cv.w), float32(cv.h), float32(cv.w), 0, 0, 0, 0, 1, 1, 1, 1, 0}
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gli.BufferData(gl_ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl_STREAM_DRAW)
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gli.ActiveTexture(gl_TEXTURE0)
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gli.BindTexture(gl_TEXTURE_2D, offscr1.tex)
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gli.UseProgram(gs.id)
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gli.Uniform1i(gs.image, 0)
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gli.Uniform2f(gs.canvasSize, float32(cv.fw), float32(cv.fh))
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gli.Uniform2f(gs.kernelScale, 1.0/float32(cv.fw), 0.0)
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gli.Uniform1fv(gs.kernel, int32(len(kernel)), &kernel[0])
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gli.VertexAttribPointer(gs.vertex, 2, gl_FLOAT, false, 0, 0)
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gli.VertexAttribPointer(gs.texCoord, 2, gl_FLOAT, false, 0, 8*4)
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gli.EnableVertexAttribArray(gs.vertex)
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gli.EnableVertexAttribArray(gs.texCoord)
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gli.DrawArrays(gl_TRIANGLE_FAN, 0, 4)
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gli.DisableVertexAttribArray(gs.vertex)
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gli.DisableVertexAttribArray(gs.texCoord)
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gli.StencilFunc(gl_ALWAYS, 0, 0xFF)
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cv.disableTextureRenderTarget()
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gli.StencilFunc(gl_EQUAL, 0, 0xFF)
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gli.BindBuffer(gl_ARRAY_BUFFER, shadowBuf)
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data = [16]float32{0, 0, 0, float32(cv.h), float32(cv.w), float32(cv.h), float32(cv.w), 0, 0, 0, 0, 1, 1, 1, 1, 0}
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gli.BufferData(gl_ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl_STREAM_DRAW)
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gli.ActiveTexture(gl_TEXTURE0)
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gli.BindTexture(gl_TEXTURE_2D, offscr2.tex)
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gli.UseProgram(gs.id)
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gli.Uniform1i(gs.image, 0)
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gli.Uniform2f(gs.canvasSize, float32(cv.fw), float32(cv.fh))
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gli.Uniform2f(gs.kernelScale, 0.0, 1.0/float32(cv.fh))
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gli.Uniform1fv(gs.kernel, int32(len(kernel)), &kernel[0])
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gli.VertexAttribPointer(gs.vertex, 2, gl_FLOAT, false, 0, 0)
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gli.VertexAttribPointer(gs.texCoord, 2, gl_FLOAT, false, 0, 8*4)
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gli.EnableVertexAttribArray(gs.vertex)
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gli.EnableVertexAttribArray(gs.texCoord)
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gli.DrawArrays(gl_TRIANGLE_FAN, 0, 4)
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gli.DisableVertexAttribArray(gs.vertex)
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gli.DisableVertexAttribArray(gs.texCoord)
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gli.StencilFunc(gl_ALWAYS, 0, 0xFF)
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gli.BlendFunc(gl_SRC_ALPHA, gl_ONE_MINUS_SRC_ALPHA)
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}
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func gaussianKernel(stddev float64, target []float32) {
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stddevSqr := stddev * stddev
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center := float64(len(target) / 2)
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factor := 1.0 / math.Sqrt(2*math.Pi*stddevSqr)
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for i := range target {
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x := float64(i) - center
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target[i] = float32(factor * math.Pow(math.E, -x*x/(2*stddevSqr)))
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}
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// normalizeKernel(target)
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}
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func normalizeKernel(kernel []float32) {
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var sum float32
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for _, v := range kernel {
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sum += v
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}
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factor := 1.0 / sum
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for i := range kernel {
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kernel[i] *= factor
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cv.b.Fill(&style, cv.shadowBuf)
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}
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}
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6
text.go
6
text.go
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@ -215,8 +215,12 @@ func (cv *Canvas) FillText(str string, x, y float64) {
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pts[2] = cv.tf(vec{float64(textOffset.X+strWidth) + x, float64(textOffset.Y+strHeight) + y + yOff})
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pts[3] = cv.tf(vec{float64(textOffset.X+strWidth) + x, float64(textOffset.Y) + y + yOff})
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mask := textImage.SubImage(image.Rect(0, 0, strWidth, strHeight)).(*image.Alpha)
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cv.drawShadow2(pts[:], mask)
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stl := cv.backendFillStyle(&cv.state.fill, 1)
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cv.b.FillImageMask(&stl, textImage.SubImage(image.Rect(0, 0, strWidth, strHeight)).(*image.Alpha), pts)
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cv.b.FillImageMask(&stl, mask, pts[:])
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}
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// StrokeText draws the given string at the given coordinates
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