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Disable DepthTest when drawing glyphs+move shared glyph draw logic

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With depth testing enabled nearby glyphs can z-fight
and so some pixels might be discarded before fragment shader
even runs, which causes us to see only part of a letter.

As such we always draw with blending enabled and depth testing
disabled so that any overlaps simply causes the char pixels to show.
This commit is contained in:
bloeys
2022-07-08 06:33:20 +04:00
parent 2b71337c4a
commit 2da4b7a53d
5 changed files with 101 additions and 166 deletions
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9
glyphs/font_atlas.go
View File

@ -2,7 +2,6 @@ package glyphs
import (
"errors"
"fmt"
"image"
"image/color"
"image/draw"
@ -146,7 +145,7 @@ func NewFontAtlasFromFont(f *truetype.Font, face font.Face, pointSize uint) (*Fo
charsOnLine := 0
drawer.Dot = fixed.P(atlas.Advance+charPaddingX, lineHeight)
const drawBoundingBoxes = false
const drawBoundingBoxes bool = false
for currGlyphCount, g := range glyphs {
@ -177,11 +176,7 @@ func NewFontAtlasFromFont(f *truetype.Font, face font.Face, pointSize uint) (*Fo
BearingX: float32(bearingX.Ceil()),
}
imgRect, mask, maskp, gAdvance, _ := face.Glyph(drawer.Dot, g)
if gAdvance == 0 {
fmt.Printf("Got advance of %s for char with code 0x%04x\n", gAdvance.String(), g)
continue
}
imgRect, mask, maskp, _, _ := face.Glyph(drawer.Dot, g)
if drawBoundingBoxes {

238
glyphs/glyphs.go
View File

@ -68,9 +68,8 @@ func (gr *GlyphRend) DrawTextOpenGLAbs(text string, screenPos *gglm.Vec3, color
pos := screenPos.Clone()
advanceF32 := float32(gr.Atlas.Advance)
lineHeightF32 := float32(gr.Atlas.LineHeight)
// scale := gglm.NewVec2(advanceF32, lineHeightF32)
buffIndex := gr.GlyphCount * floatsPerGlyph
bufIndex := gr.GlyphCount * floatsPerGlyph
for _, run := range runs {
@ -91,155 +90,15 @@ func (gr *GlyphRend) DrawTextOpenGLAbs(text string, screenPos *gglm.Vec3, color
if isLtr {
for i := 0; i < len(rs); i++ {
r := rs[i]
if r == '\n' {
screenPos.SetY(screenPos.Y() - lineHeightF32)
pos = screenPos.Clone()
prevRune = r
continue
} else if r == ' ' {
pos.AddX(advanceF32)
prevRune = r
continue
} else if r == '\t' {
pos.AddX(advanceF32 * float32(gr.SpacesPerTab))
prevRune = r
continue
}
var g FontAtlasGlyph
if i < len(rs)-1 {
//start or middle of sentence
g = gr.glyphFromRunes(r, prevRune, rs[i+1])
} else {
//Last character
g = gr.glyphFromRunes(r, prevRune, invalidRune)
}
//See: https://developer.apple.com/library/archive/documentation/TextFonts/Conceptual/CocoaTextArchitecture/Art/glyph_metrics_2x.png
//The uvs coming in make it so that glyphs are sitting on top of the baseline (no descent) and with horizontal bearing applied.
//So to position correctly we move them down by the descent amount.
drawPos := *pos
drawPos.SetX(drawPos.X() + g.BearingX)
drawPos.SetY(drawPos.Y() - g.Descent)
//Add the glyph information to the vbo
//UV
gr.GlyphVBO[buffIndex+0] = g.U
gr.GlyphVBO[buffIndex+1] = g.V
buffIndex += 2
//UVSize
gr.GlyphVBO[buffIndex+0] = g.SizeU
gr.GlyphVBO[buffIndex+1] = g.SizeV
buffIndex += 2
//Color
gr.GlyphVBO[buffIndex+0] = color.R()
gr.GlyphVBO[buffIndex+1] = color.G()
gr.GlyphVBO[buffIndex+2] = color.B()
gr.GlyphVBO[buffIndex+3] = color.A()
buffIndex += 4
//Model Pos
gr.GlyphVBO[buffIndex+0] = drawPos.X()
gr.GlyphVBO[buffIndex+1] = drawPos.Y()
gr.GlyphVBO[buffIndex+2] = drawPos.Z()
buffIndex += 3
//Model Scale
gr.GlyphVBO[buffIndex+0] = g.SizeU
gr.GlyphVBO[buffIndex+1] = g.SizeV
buffIndex += 2
gr.GlyphCount++
pos.AddX(advanceF32)
//If we fill the buffer we issue a draw call
if gr.GlyphCount == MaxGlyphsPerBatch {
gr.Draw()
buffIndex = 0
}
prevRune = r
gr.drawRune(rs, i, prevRune, screenPos, pos, color, advanceF32, lineHeightF32, &bufIndex, isLtr)
prevRune = rs[i]
}
} else {
for i := len(rs) - 1; i >= 0; i-- {
r := rs[i]
if r == '\n' {
screenPos.SetY(screenPos.Y() - lineHeightF32)
pos = screenPos.Clone()
prevRune = r
continue
} else if r == ' ' {
pos.AddX(advanceF32)
prevRune = r
continue
} else if r == '\t' {
pos.AddX(advanceF32 * float32(gr.SpacesPerTab))
prevRune = r
continue
}
var g FontAtlasGlyph
if i > 0 {
//start or middle of sentence
g = gr.glyphFromRunes(r, rs[i-1], prevRune)
} else {
//Last character
g = gr.glyphFromRunes(r, invalidRune, prevRune)
}
//See: https://developer.apple.com/library/archive/documentation/TextFonts/Conceptual/CocoaTextArchitecture/Art/glyph_metrics_2x.png
//The uvs coming in make it so that glyphs are sitting on top of the baseline (no descent) and with horizontal bearing applied.
//So to position correctly we move them down by the descent amount.
drawPos := *pos
drawPos.SetX(drawPos.X() + g.BearingX)
drawPos.SetY(drawPos.Y() - g.Descent)
//Add the glyph information to the vbo
//UV
gr.GlyphVBO[buffIndex+0] = g.U
gr.GlyphVBO[buffIndex+1] = g.V
buffIndex += 2
//UVSize
gr.GlyphVBO[buffIndex+0] = g.SizeU
gr.GlyphVBO[buffIndex+1] = g.SizeV
buffIndex += 2
//Color
gr.GlyphVBO[buffIndex+0] = color.R()
gr.GlyphVBO[buffIndex+1] = color.G()
gr.GlyphVBO[buffIndex+2] = color.B()
gr.GlyphVBO[buffIndex+3] = color.A()
buffIndex += 4
//Model Pos
gr.GlyphVBO[buffIndex+0] = drawPos.X()
gr.GlyphVBO[buffIndex+1] = drawPos.Y()
gr.GlyphVBO[buffIndex+2] = drawPos.Z()
buffIndex += 3
//Model Scale
gr.GlyphVBO[buffIndex+0] = g.SizeU
gr.GlyphVBO[buffIndex+1] = g.SizeV
buffIndex += 2
gr.GlyphCount++
pos.AddX(advanceF32)
//If we fill the buffer we issue a draw call
if gr.GlyphCount == MaxGlyphsPerBatch {
gr.Draw()
buffIndex = 0
}
prevRune = r
gr.drawRune(rs, i, prevRune, screenPos, pos, color, advanceF32, lineHeightF32, &bufIndex, isLtr)
prevRune = rs[i]
}
}
@ -247,8 +106,92 @@ func (gr *GlyphRend) DrawTextOpenGLAbs(text string, screenPos *gglm.Vec3, color
}
}
func (gr *GlyphRend) drawRune(rs []rune, i int, prevRune rune, screenPos, pos *gglm.Vec3, color *gglm.Vec4, advanceF32, lineHeightF32 float32, bufIndex *uint32, isLtr bool) {
r := rs[i]
if r == '\n' {
screenPos.SetY(screenPos.Y() - lineHeightF32)
*pos = *screenPos.Clone()
// prevRune = r
return
} else if r == ' ' {
pos.AddX(advanceF32)
// prevRune = r
return
} else if r == '\t' {
pos.AddX(advanceF32 * float32(gr.SpacesPerTab))
// prevRune = r
return
}
var g FontAtlasGlyph
if isLtr {
if i < len(rs)-1 {
//start or middle of sentence
g = gr.glyphFromRunes(r, prevRune, rs[i+1])
} else {
//Last character
g = gr.glyphFromRunes(r, prevRune, invalidRune)
}
} else {
if i > 0 {
//start or middle of sentence
g = gr.glyphFromRunes(r, rs[i-1], prevRune)
} else {
//Last character
g = gr.glyphFromRunes(r, invalidRune, prevRune)
}
}
//We must adjust char positioning according to: https://developer.apple.com/library/archive/documentation/TextFonts/Conceptual/CocoaTextArchitecture/Art/glyph_metrics_2x.png
drawPos := *pos
drawPos.SetX(drawPos.X() + g.BearingX)
drawPos.SetY(drawPos.Y() - g.Descent)
//Add the glyph information to the vbo
//UV
gr.GlyphVBO[*bufIndex+0] = g.U
gr.GlyphVBO[*bufIndex+1] = g.V
*bufIndex += 2
//UVSize
gr.GlyphVBO[*bufIndex+0] = g.SizeU
gr.GlyphVBO[*bufIndex+1] = g.SizeV
*bufIndex += 2
//Color
gr.GlyphVBO[*bufIndex+0] = color.R()
gr.GlyphVBO[*bufIndex+1] = color.G()
gr.GlyphVBO[*bufIndex+2] = color.B()
gr.GlyphVBO[*bufIndex+3] = color.A()
*bufIndex += 4
//Model Pos
gr.GlyphVBO[*bufIndex+0] = drawPos.X()
gr.GlyphVBO[*bufIndex+1] = drawPos.Y()
gr.GlyphVBO[*bufIndex+2] = drawPos.Z()
*bufIndex += 3
//Model Scale
gr.GlyphVBO[*bufIndex+0] = g.SizeU
gr.GlyphVBO[*bufIndex+1] = g.SizeV
*bufIndex += 2
gr.GlyphCount++
pos.AddX(advanceF32)
//If we fill the buffer we issue a draw call
if gr.GlyphCount == MaxGlyphsPerBatch {
gr.Draw()
*bufIndex = 0
}
// prevRune = r
}
func (gr *GlyphRend) GetTextRuns(t string) [][]rune {
//PERF: Might be better to pass a [][]rune buffer to avoid allocating on the heap
rs := []rune(t)
if len(rs) == 0 {
@ -405,7 +348,10 @@ func (gr *GlyphRend) Draw() {
gr.InstancedBuf.Bind()
gr.GlyphMat.Bind()
//We need to disable depth testing so that nearby characters don't occlude each other
gl.Disable(gl.DEPTH_TEST)
gl.DrawElementsInstanced(gl.TRIANGLES, gr.GlyphMesh.Buf.IndexBufCount, gl.UNSIGNED_INT, gl.PtrOffset(0), int32(gr.GlyphCount))
gl.Enable(gl.DEPTH_TEST)
gr.GlyphCount = 0
}

6
go.mod
View File

@ -7,11 +7,9 @@ require (
github.com/bloeys/nmage v0.12.13
github.com/go-gl/gl v0.0.0-20211025173605-bda47ffaa784
github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
github.com/inkyblackness/imgui-go/v4 v4.3.0
github.com/veandco/go-sdl2 v0.4.10
golang.org/x/image v0.0.0-20220617043117-41969df76e82
)
require (
github.com/bloeys/assimp-go v0.4.2 // indirect
github.com/inkyblackness/imgui-go/v4 v4.3.0 // indirect
)
require github.com/bloeys/assimp-go v0.4.2 // indirect

12
main.go
View File

@ -11,7 +11,6 @@ import (
"github.com/bloeys/nmage/meshes"
"github.com/bloeys/nmage/renderer/rend3dgl"
nmageimgui "github.com/bloeys/nmage/ui/imgui"
"github.com/bloeys/nterm/assert"
"github.com/bloeys/nterm/glyphs"
"github.com/golang/freetype/truetype"
"github.com/inkyblackness/imgui-go/v4"
@ -60,7 +59,7 @@ func main() {
rend: rend,
imguiInfo: nmageimgui.NewImGUI(),
FontSize: 20,
FontSize: 14,
}
p.win.EventCallbacks = append(p.win.EventCallbacks, func(e sdl.Event) {
@ -92,7 +91,7 @@ func (p *program) Init() {
fmt.Printf("DPI: %f, font size: %d\n", dpi, p.FontSize)
w, h := p.win.SDLWin.GetSize()
p.GlyphRend, err = glyphs.NewGlyphRend("./res/fonts/Consolas.ttf", &truetype.Options{Size: float64(p.FontSize), DPI: p.Dpi, SubPixelsX: subPixelX, SubPixelsY: subPixelY, Hinting: hinting}, w, h)
p.GlyphRend, err = glyphs.NewGlyphRend("./res/fonts/KawkabMono-Regular.ttf", &truetype.Options{Size: float64(p.FontSize), DPI: p.Dpi, SubPixelsX: subPixelX, SubPixelsY: subPixelY, Hinting: hinting}, w, h)
if err != nil {
panic("Failed to create atlas from font file. Err: " + err.Error())
}
@ -169,12 +168,9 @@ func (p *program) Update() {
}
imgui.InputText("", &textToShow)
if len(textToShow) > 0 {
assert.T(len(textToShow) == len(p.GlyphRend.GetTextRuns(textToShow)[0]), "??")
}
}
var textToShow = "Hello there my friend"
var textToShow = " Hello there يا friend. أسمي عمر wow!"
var xOff float32 = 0
var yOff float32 = 0
@ -211,7 +207,7 @@ func (p *program) Render() {
str := textToShow
// str := "مرحبا بك my friend"
// str := "my, friend"
// str := " hello there يا friend. سمي عمر wow"
// str := " hello there يا friend. أسمي عمر wow"
// str := " ijojo\n\n Hello there, friend|. pq?\n ABCDEFG\tHIJKLMNOPQRSTUVWXYZ\nمرحبا بك"
// str := " ijojo\n\n Hello there, friend|. pq?\n ABCDEFG\tHIJKLMNOPQRSTUVWXYZ"

2
res/shaders/glyph.glsl
View File

@ -46,7 +46,7 @@ uniform sampler2D diffTex;
void main()
{
vec4 texColor = texelFetch(diffTex, ivec2(v2fUV0), 0);
// vec4 texColor = texture(diffTex, v2fUV0);
// This commented out part highlights the full region of the char
// if (texColor.r == 0)
// {
// fragColor = vec4(0,1,0,0.25);