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replaced the gaussian shadow shaders with box blur shaders

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This commit is contained in:
Thomas Friedel 2020-02-11 15:45:48 +01:00
parent 598ac1e325
commit f5e7e6a060
3 changed files with 104 additions and 177 deletions
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116
backend/goglbackend/fill.go
View file

@ -228,82 +228,78 @@ func (b *GoGLBackend) FillImageMask(style *backendbase.FillStyle, mask *image.Al
} }
} }
func (b *GoGLBackend) drawBlurred(blur float64) { func (b *GoGLBackend) drawBlurred(size float64) {
var kernel []float32 b.offscr1.alpha = true
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.offscr2.alpha = true
b.enableTextureRenderTarget(&b.offscr2)
gl.Disable(gl.STENCIL_TEST)
gl.Disable(gl.BLEND)
gl.BindBuffer(gl.ARRAY_BUFFER, b.shadowBuf) 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} data := [16]float32{
0, 0, 0, float32(b.h), float32(b.w), float32(b.h), float32(b.w), 0,
0, 1, 0, 0, 1, 0, 1, 1}
gl.BufferData(gl.ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl.STREAM_DRAW) gl.BufferData(gl.ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl.STREAM_DRAW)
gl.VertexAttribPointer(gs.Vertex, 2, gl.FLOAT, false, 0, nil) gl.UseProgram(b.bbshd.ID)
gl.VertexAttribPointer(gs.TexCoord, 2, gl.FLOAT, false, 0, gl.PtrOffset(8*4)) gl.Uniform1i(b.bbshd.Image, 0)
gl.EnableVertexAttribArray(gs.Vertex) gl.Uniform2f(b.bbshd.CanvasSize, float32(b.fw), float32(b.fh))
gl.EnableVertexAttribArray(gs.TexCoord)
gl.VertexAttribPointer(b.bbshd.Vertex, 2, gl.FLOAT, false, 0, nil)
gl.VertexAttribPointer(b.bbshd.TexCoord, 2, gl.FLOAT, false, 0, gl.PtrOffset(8*4))
gl.EnableVertexAttribArray(b.bbshd.Vertex)
gl.EnableVertexAttribArray(b.bbshd.TexCoord)
gl.Disable(gl.BLEND)
gl.ActiveTexture(gl.TEXTURE0) gl.ActiveTexture(gl.TEXTURE0)
// calculate box blur size
fsize := math.Max(1, math.Floor(size))
sizea := int(fsize)
sizeb := sizea
sizec := sizea
if size-fsize > 0.333333333 {
sizeb++
}
if size-fsize > 0.666666666 {
sizec++
}
gl.BindTexture(gl.TEXTURE_2D, b.offscr1.tex) gl.BindTexture(gl.TEXTURE_2D, b.offscr1.tex)
b.enableTextureRenderTarget(&b.offscr2)
gl.UseProgram(gs.ID) b.box3(sizea, false)
gl.Uniform1i(gs.Image, 0) gl.BindTexture(gl.TEXTURE_2D, b.offscr2.tex)
gl.Uniform2f(gs.CanvasSize, float32(b.fw), float32(b.fh)) b.enableTextureRenderTarget(&b.offscr1)
gl.Uniform2f(gs.KernelScale, 1.0/float32(b.fw), 0.0) b.box3(sizeb, false)
gl.Uniform1fv(gs.Kernel, int32(len(kernel)), &kernel[0]) gl.BindTexture(gl.TEXTURE_2D, b.offscr1.tex)
gl.DrawArrays(gl.TRIANGLE_FAN, 0, 4) b.enableTextureRenderTarget(&b.offscr2)
b.box3(sizec, false)
b.disableTextureRenderTarget() gl.BindTexture(gl.TEXTURE_2D, b.offscr2.tex)
b.enableTextureRenderTarget(&b.offscr1)
b.box3(sizea, true)
gl.BindTexture(gl.TEXTURE_2D, b.offscr1.tex)
b.enableTextureRenderTarget(&b.offscr2)
b.box3(sizeb, true)
gl.Enable(gl.BLEND) gl.Enable(gl.BLEND)
gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA) gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
gl.BindTexture(gl.TEXTURE_2D, b.offscr2.tex) gl.BindTexture(gl.TEXTURE_2D, b.offscr2.tex)
b.disableTextureRenderTarget()
b.box3(sizec, true)
gl.Uniform2f(gs.KernelScale, 0.0, 1.0/float32(b.fh)) gl.DisableVertexAttribArray(b.bbshd.Vertex)
gl.DrawArrays(gl.TRIANGLE_FAN, 0, 4) gl.DisableVertexAttribArray(b.bbshd.TexCoord)
gl.DisableVertexAttribArray(gs.Vertex)
gl.DisableVertexAttribArray(gs.TexCoord)
gl.Enable(gl.STENCIL_TEST)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA) gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
} }
func gaussianKernel(stddev float64, target []float32) { func (b *GoGLBackend) box3(size int, vertical bool) {
stddevSqr := stddev * stddev gl.Uniform1i(b.bbshd.BoxSize, int32(size))
center := float64(len(target) / 2) if vertical {
factor := 1.0 / math.Sqrt(2*math.Pi*stddevSqr) gl.Uniform1i(b.bbshd.BoxVertical, 1)
for i := range target { gl.Uniform1f(b.bbshd.BoxScale, 1/float32(b.fh))
x := float64(i) - center } else {
target[i] = float32(factor * math.Pow(math.E, -x*x/(2*stddevSqr))) gl.Uniform1i(b.bbshd.BoxVertical, 0)
gl.Uniform1f(b.bbshd.BoxScale, 1/float32(b.fw))
} }
// normalizeKernel(target) gl.DrawArrays(gl.TRIANGLE_FAN, 0, 4)
}
func normalizeKernel(kernel []float32) { gl.StencilFunc(gl.ALWAYS, 0, 0xFF)
var sum float32
for _, v := range kernel {
sum += v
}
factor := 1.0 / sum
for i := range kernel {
kernel[i] *= factor
}
} }

28
backend/goglbackend/gogl.go
View file

@ -20,10 +20,8 @@ type GLContext struct {
shadowBuf uint32 shadowBuf uint32
alphaTex uint32 alphaTex uint32
shd unifiedShader shd unifiedShader
gauss15r gaussianShader bbshd boxBlurShader
gauss63r gaussianShader
gauss127r gaussianShader
offscr1 offscreenBuffer offscr1 offscreenBuffer
offscr2 offscreenBuffer offscr2 offscreenBuffer
@ -60,29 +58,11 @@ func NewGLContext() (*GLContext, error) {
return nil, err return nil, err
} }
err = loadShader(gaussian15VS, gaussian15FS, &ctx.gauss15r.shaderProgram) err = loadShader(boxVS, boxFS, &ctx.bbshd.shaderProgram)
if err != nil { if err != nil {
return nil, err return nil, err
} }
ctx.gauss15r.shaderProgram.mustLoadLocations(&ctx.gauss15r) ctx.bbshd.shaderProgram.mustLoadLocations(&ctx.bbshd)
if err = glError(); err != nil {
return nil, err
}
err = loadShader(gaussian63VS, gaussian63FS, &ctx.gauss63r.shaderProgram)
if err != nil {
return nil, err
}
ctx.gauss63r.shaderProgram.mustLoadLocations(&ctx.gauss63r)
if err = glError(); err != nil {
return nil, err
}
err = loadShader(gaussian127VS, gaussian127FS, &ctx.gauss127r.shaderProgram)
if err != nil {
return nil, err
}
ctx.gauss127r.shaderProgram.mustLoadLocations(&ctx.gauss127r)
if err = glError(); err != nil { if err = glError(); err != nil {
return nil, err return nil, err
} }

137
backend/goglbackend/shaders.go
View file

@ -1,11 +1,5 @@
package goglbackend package goglbackend
import (
"bytes"
"fmt"
"strings"
)
var unifiedVS = ` var unifiedVS = `
attribute vec2 vertex, texCoord; attribute vec2 vertex, texCoord;
@ -100,96 +94,52 @@ void main() {
} }
` `
var gaussian15VS = ` var boxVS = `
attribute vec2 vertex, texCoord; attribute vec2 vertex, texCoord;
uniform vec2 canvasSize; uniform vec2 canvasSize;
varying vec2 v_texCoord;
varying vec2 v_cp, v_tc;
void main() { void main() {
v_texCoord = texCoord; v_tc = texCoord;
v_cp = vertex;
vec2 glp = vertex * 2.0 / canvasSize - 1.0; vec2 glp = vertex * 2.0 / canvasSize - 1.0;
gl_Position = vec4(glp.x, -glp.y, 0.0, 1.0); gl_Position = vec4(glp.x, -glp.y, 0.0, 1.0);
}`
var gaussian15FS = `
#ifdef GL_ES
precision mediump float;
#endif
varying vec2 v_texCoord;
uniform vec2 kernelScale;
uniform sampler2D image;
uniform float kernel[15];
void main() {
vec4 color = vec4(0.0, 0.0, 0.0, 0.0);
_SUM_
gl_FragColor = color;
}`
var gaussian63VS = `
attribute vec2 vertex, texCoord;
uniform vec2 canvasSize;
varying vec2 v_texCoord;
void main() {
v_texCoord = texCoord;
vec2 glp = vertex * 2.0 / canvasSize - 1.0;
gl_Position = vec4(glp.x, -glp.y, 0.0, 1.0);
}`
var gaussian63FS = `
#ifdef GL_ES
precision mediump float;
#endif
varying vec2 v_texCoord;
uniform vec2 kernelScale;
uniform sampler2D image;
uniform float kernel[63];
void main() {
vec4 color = vec4(0.0, 0.0, 0.0, 0.0);
_SUM_
gl_FragColor = color;
}`
var gaussian127VS = `
attribute vec2 vertex, texCoord;
uniform vec2 canvasSize;
varying vec2 v_texCoord;
void main() {
v_texCoord = texCoord;
vec2 glp = vertex * 2.0 / canvasSize - 1.0;
gl_Position = vec4(glp.x, -glp.y, 0.0, 1.0);
}`
var gaussian127FS = `
#ifdef GL_ES
precision mediump float;
#endif
varying vec2 v_texCoord;
uniform vec2 kernelScale;
uniform sampler2D image;
uniform float kernel[127];
void main() {
vec4 color = vec4(0.0, 0.0, 0.0, 0.0);
_SUM_
gl_FragColor = color;
}`
func init() {
fstr := "\tcolor += texture2D(image, v_texCoord + vec2(%.1f * kernelScale.x, %.1f * kernelScale.y)) * kernel[%d];\n"
bb := bytes.Buffer{}
for i := 0; i < 127; i++ {
off := float64(i) - 63
fmt.Fprintf(&bb, fstr, off, off, i)
}
gaussian127FS = strings.Replace(gaussian127FS, "_SUM_", bb.String(), -1)
bb.Reset()
for i := 0; i < 63; i++ {
off := float64(i) - 31
fmt.Fprintf(&bb, fstr, off, off, i)
}
gaussian63FS = strings.Replace(gaussian63FS, "_SUM_", bb.String(), -1)
bb.Reset()
for i := 0; i < 15; i++ {
off := float64(i) - 7
fmt.Fprintf(&bb, fstr, off, off, i)
}
gaussian15FS = strings.Replace(gaussian15FS, "_SUM_", bb.String(), -1)
} }
`
var boxFS = `
#ifdef GL_ES
precision mediump float;
#endif
varying vec2 v_cp, v_tc;
uniform int boxSize;
uniform bool boxVertical;
uniform float boxScale;
uniform sampler2D image;
void main() {
vec4 color = vec4(0.0, 0.0, 0.0, 0.0);
vec4 sum = vec4(0.0);
if (boxVertical) {
vec2 start = v_tc - vec2(0.0, (float)(boxSize) * boxScale);
for (int i=0; i<boxSize*2; i++) {
sum += texture2D(image, start + vec2(0.0, (float)(i) * boxScale));
}
} else {
vec2 start = v_tc - vec2((float)(boxSize) * boxScale, 0.0);
for (int i=0; i<boxSize*2; i++) {
sum += texture2D(image, start + vec2((float)(i) * boxScale, 0.0));
}
}
color = sum / float(boxSize * 2);
gl_FragColor = color;
}
`
type unifiedShader struct { type unifiedShader struct {
shaderProgram shaderProgram
@ -220,12 +170,13 @@ type unifiedShader struct {
UseImage int32 UseImage int32
} }
type gaussianShader struct { type boxBlurShader struct {
shaderProgram shaderProgram
Vertex uint32 Vertex uint32
TexCoord uint32 TexCoord uint32
CanvasSize int32 CanvasSize int32
KernelScale int32 BoxSize int32
BoxVertical int32
BoxScale int32
Image int32 Image int32
Kernel int32
} }