replaced the gaussian shadow shaders with box blur shaders
This commit is contained in:
Thomas Friedel
parent
598ac1e325
commit
f5e7e6a060
3 changed files with 104 additions and 177 deletions
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@ -228,82 +228,78 @@ func (b *GoGLBackend) FillImageMask(style *backendbase.FillStyle, mask *image.Al
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}
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}
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func (b *GoGLBackend) drawBlurred(blur float64) {
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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 blur < 3 {
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gs = &b.gauss15r
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kernel = kernelBuf[:15]
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} else if blur < 12 {
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gs = &b.gauss63r
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kernel = kernelBuf[:63]
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} else {
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gs = &b.gauss127r
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kernel = kernelBuf[:127]
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}
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gaussianKernel(blur, kernel)
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func (b *GoGLBackend) drawBlurred(size float64) {
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b.offscr1.alpha = true
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b.offscr2.alpha = true
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b.enableTextureRenderTarget(&b.offscr2)
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gl.Disable(gl.STENCIL_TEST)
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gl.Disable(gl.BLEND)
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gl.BindBuffer(gl.ARRAY_BUFFER, b.shadowBuf)
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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}
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data := [16]float32{
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0, 0, 0, float32(b.h), float32(b.w), float32(b.h), float32(b.w), 0,
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0, 1, 0, 0, 1, 0, 1, 1}
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gl.BufferData(gl.ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl.STREAM_DRAW)
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gl.VertexAttribPointer(gs.Vertex, 2, gl.FLOAT, false, 0, nil)
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gl.VertexAttribPointer(gs.TexCoord, 2, gl.FLOAT, false, 0, gl.PtrOffset(8*4))
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gl.EnableVertexAttribArray(gs.Vertex)
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gl.EnableVertexAttribArray(gs.TexCoord)
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gl.UseProgram(b.bbshd.ID)
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gl.Uniform1i(b.bbshd.Image, 0)
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gl.Uniform2f(b.bbshd.CanvasSize, float32(b.fw), float32(b.fh))
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gl.VertexAttribPointer(b.bbshd.Vertex, 2, gl.FLOAT, false, 0, nil)
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gl.VertexAttribPointer(b.bbshd.TexCoord, 2, gl.FLOAT, false, 0, gl.PtrOffset(8*4))
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gl.EnableVertexAttribArray(b.bbshd.Vertex)
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gl.EnableVertexAttribArray(b.bbshd.TexCoord)
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gl.Disable(gl.BLEND)
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gl.ActiveTexture(gl.TEXTURE0)
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// calculate box blur size
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fsize := math.Max(1, math.Floor(size))
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sizea := int(fsize)
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sizeb := sizea
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sizec := sizea
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if size-fsize > 0.333333333 {
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sizeb++
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}
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if size-fsize > 0.666666666 {
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sizec++
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}
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gl.BindTexture(gl.TEXTURE_2D, b.offscr1.tex)
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gl.UseProgram(gs.ID)
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gl.Uniform1i(gs.Image, 0)
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gl.Uniform2f(gs.CanvasSize, float32(b.fw), float32(b.fh))
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gl.Uniform2f(gs.KernelScale, 1.0/float32(b.fw), 0.0)
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gl.Uniform1fv(gs.Kernel, int32(len(kernel)), &kernel[0])
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gl.DrawArrays(gl.TRIANGLE_FAN, 0, 4)
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b.disableTextureRenderTarget()
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b.enableTextureRenderTarget(&b.offscr2)
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b.box3(sizea, false)
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gl.BindTexture(gl.TEXTURE_2D, b.offscr2.tex)
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b.enableTextureRenderTarget(&b.offscr1)
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b.box3(sizeb, false)
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gl.BindTexture(gl.TEXTURE_2D, b.offscr1.tex)
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b.enableTextureRenderTarget(&b.offscr2)
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b.box3(sizec, false)
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gl.BindTexture(gl.TEXTURE_2D, b.offscr2.tex)
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b.enableTextureRenderTarget(&b.offscr1)
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b.box3(sizea, true)
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gl.BindTexture(gl.TEXTURE_2D, b.offscr1.tex)
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b.enableTextureRenderTarget(&b.offscr2)
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b.box3(sizeb, true)
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gl.Enable(gl.BLEND)
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gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
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gl.BindTexture(gl.TEXTURE_2D, b.offscr2.tex)
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b.disableTextureRenderTarget()
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b.box3(sizec, true)
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gl.Uniform2f(gs.KernelScale, 0.0, 1.0/float32(b.fh))
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gl.DrawArrays(gl.TRIANGLE_FAN, 0, 4)
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gl.DisableVertexAttribArray(b.bbshd.Vertex)
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gl.DisableVertexAttribArray(b.bbshd.TexCoord)
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gl.DisableVertexAttribArray(gs.Vertex)
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gl.DisableVertexAttribArray(gs.TexCoord)
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gl.Enable(gl.STENCIL_TEST)
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gl.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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func (b *GoGLBackend) box3(size int, vertical bool) {
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gl.Uniform1i(b.bbshd.BoxSize, int32(size))
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if vertical {
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gl.Uniform1i(b.bbshd.BoxVertical, 1)
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gl.Uniform1f(b.bbshd.BoxScale, 1/float32(b.fh))
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} else {
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gl.Uniform1i(b.bbshd.BoxVertical, 0)
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gl.Uniform1f(b.bbshd.BoxScale, 1/float32(b.fw))
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}
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// normalizeKernel(target)
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}
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gl.DrawArrays(gl.TRIANGLE_FAN, 0, 4)
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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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}
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gl.StencilFunc(gl.ALWAYS, 0, 0xFF)
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}
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@ -20,10 +20,8 @@ type GLContext struct {
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shadowBuf uint32
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alphaTex uint32
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shd unifiedShader
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gauss15r gaussianShader
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gauss63r gaussianShader
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gauss127r gaussianShader
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shd unifiedShader
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bbshd boxBlurShader
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offscr1 offscreenBuffer
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offscr2 offscreenBuffer
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@ -60,29 +58,11 @@ func NewGLContext() (*GLContext, error) {
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return nil, err
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}
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err = loadShader(gaussian15VS, gaussian15FS, &ctx.gauss15r.shaderProgram)
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err = loadShader(boxVS, boxFS, &ctx.bbshd.shaderProgram)
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if err != nil {
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return nil, err
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}
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ctx.gauss15r.shaderProgram.mustLoadLocations(&ctx.gauss15r)
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if err = glError(); err != nil {
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return nil, err
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}
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err = loadShader(gaussian63VS, gaussian63FS, &ctx.gauss63r.shaderProgram)
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if err != nil {
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return nil, err
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}
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ctx.gauss63r.shaderProgram.mustLoadLocations(&ctx.gauss63r)
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if err = glError(); err != nil {
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return nil, err
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}
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err = loadShader(gaussian127VS, gaussian127FS, &ctx.gauss127r.shaderProgram)
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if err != nil {
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return nil, err
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}
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ctx.gauss127r.shaderProgram.mustLoadLocations(&ctx.gauss127r)
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ctx.bbshd.shaderProgram.mustLoadLocations(&ctx.bbshd)
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if err = glError(); err != nil {
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return nil, err
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}
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@ -1,11 +1,5 @@
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package goglbackend
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import (
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"bytes"
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"fmt"
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"strings"
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)
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var unifiedVS = `
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attribute vec2 vertex, texCoord;
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@ -100,96 +94,52 @@ void main() {
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}
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`
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var gaussian15VS = `
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var boxVS = `
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attribute vec2 vertex, texCoord;
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uniform vec2 canvasSize;
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varying vec2 v_texCoord;
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varying vec2 v_cp, v_tc;
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void main() {
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v_texCoord = texCoord;
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v_tc = texCoord;
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v_cp = vertex;
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vec2 glp = vertex * 2.0 / canvasSize - 1.0;
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gl_Position = vec4(glp.x, -glp.y, 0.0, 1.0);
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}`
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var gaussian15FS = `
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#ifdef GL_ES
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precision mediump float;
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#endif
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varying vec2 v_texCoord;
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uniform vec2 kernelScale;
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uniform sampler2D image;
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uniform float kernel[15];
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void main() {
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vec4 color = vec4(0.0, 0.0, 0.0, 0.0);
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_SUM_
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gl_FragColor = color;
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}`
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var gaussian63VS = `
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attribute vec2 vertex, texCoord;
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uniform vec2 canvasSize;
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varying vec2 v_texCoord;
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void main() {
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v_texCoord = texCoord;
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vec2 glp = vertex * 2.0 / canvasSize - 1.0;
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gl_Position = vec4(glp.x, -glp.y, 0.0, 1.0);
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}`
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var gaussian63FS = `
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#ifdef GL_ES
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precision mediump float;
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#endif
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varying vec2 v_texCoord;
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uniform vec2 kernelScale;
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uniform sampler2D image;
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uniform float kernel[63];
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void main() {
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vec4 color = vec4(0.0, 0.0, 0.0, 0.0);
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_SUM_
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gl_FragColor = color;
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}`
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var gaussian127VS = `
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attribute vec2 vertex, texCoord;
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uniform vec2 canvasSize;
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varying vec2 v_texCoord;
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void main() {
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v_texCoord = texCoord;
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vec2 glp = vertex * 2.0 / canvasSize - 1.0;
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gl_Position = vec4(glp.x, -glp.y, 0.0, 1.0);
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}`
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var gaussian127FS = `
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#ifdef GL_ES
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precision mediump float;
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#endif
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varying vec2 v_texCoord;
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uniform vec2 kernelScale;
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uniform sampler2D image;
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uniform float kernel[127];
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void main() {
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vec4 color = vec4(0.0, 0.0, 0.0, 0.0);
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_SUM_
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gl_FragColor = color;
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}`
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func init() {
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fstr := "\tcolor += texture2D(image, v_texCoord + vec2(%.1f * kernelScale.x, %.1f * kernelScale.y)) * kernel[%d];\n"
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bb := bytes.Buffer{}
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for i := 0; i < 127; i++ {
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off := float64(i) - 63
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fmt.Fprintf(&bb, fstr, off, off, i)
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}
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gaussian127FS = strings.Replace(gaussian127FS, "_SUM_", bb.String(), -1)
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bb.Reset()
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for i := 0; i < 63; i++ {
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off := float64(i) - 31
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fmt.Fprintf(&bb, fstr, off, off, i)
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}
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gaussian63FS = strings.Replace(gaussian63FS, "_SUM_", bb.String(), -1)
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bb.Reset()
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for i := 0; i < 15; i++ {
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off := float64(i) - 7
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fmt.Fprintf(&bb, fstr, off, off, i)
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}
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gaussian15FS = strings.Replace(gaussian15FS, "_SUM_", bb.String(), -1)
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}
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`
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var boxFS = `
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#ifdef GL_ES
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precision mediump float;
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#endif
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varying vec2 v_cp, v_tc;
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uniform int boxSize;
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uniform bool boxVertical;
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uniform float boxScale;
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uniform sampler2D image;
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void main() {
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vec4 color = vec4(0.0, 0.0, 0.0, 0.0);
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vec4 sum = vec4(0.0);
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if (boxVertical) {
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vec2 start = v_tc - vec2(0.0, (float)(boxSize) * boxScale);
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for (int i=0; i<boxSize*2; i++) {
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sum += texture2D(image, start + vec2(0.0, (float)(i) * boxScale));
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}
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} else {
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vec2 start = v_tc - vec2((float)(boxSize) * boxScale, 0.0);
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for (int i=0; i<boxSize*2; i++) {
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sum += texture2D(image, start + vec2((float)(i) * boxScale, 0.0));
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}
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}
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color = sum / float(boxSize * 2);
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gl_FragColor = color;
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}
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`
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type unifiedShader struct {
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shaderProgram
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@ -220,12 +170,13 @@ type unifiedShader struct {
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UseImage int32
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}
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type gaussianShader struct {
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type boxBlurShader struct {
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shaderProgram
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Vertex uint32
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TexCoord uint32
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CanvasSize int32
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KernelScale int32
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BoxSize int32
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BoxVertical int32
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BoxScale int32
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Image int32
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Kernel int32
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}
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