Abstract glyph renderer

This commit is contained in:
bloeys
2022-07-01 10:20:30 +04:00
parent aa9aa8347c
commit 224f33bf9f
3 changed files with 477 additions and 491 deletions

156
glyphs/font_atlas.go Executable file
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@ -0,0 +1,156 @@
package glyphs
import (
"image"
"image/draw"
"image/png"
"math"
"os"
"github.com/bloeys/nterm/assert"
"github.com/golang/freetype/truetype"
"golang.org/x/image/font"
"golang.org/x/image/math/fixed"
)
type FontAtlas struct {
Font *truetype.Font
Img *image.RGBA
Glyphs map[rune]FontAtlasGlyph
LineHeight int
}
type FontAtlasGlyph struct {
U float32
V float32
SizeU float32
SizeV float32
Ascent float32
Descent float32
Advance float32
}
func NewFontAtlasFromFile(fontFile string, fontOptions *truetype.Options) (*FontAtlas, error) {
fBytes, err := os.ReadFile(fontFile)
if err != nil {
return nil, err
}
f, err := truetype.Parse(fBytes)
if err != nil {
return nil, err
}
face := truetype.NewFace(f, fontOptions)
atlas := NewFontAtlasFromFont(f, face, uint(fontOptions.Size))
return atlas, nil
}
func NewFontAtlasFromFont(f *truetype.Font, face font.Face, pointSize uint) *FontAtlas {
const maxAtlasSize = 8192
glyphs := getGlyphsFromRanges(getGlyphRanges(f))
assert.T(len(glyphs) > 0, "no glyphs")
//Choose atlas size
atlasSizeX := 512
atlasSizeY := 512
_, charWidthFixed, _ := face.GlyphBounds(glyphs[0])
charWidth := charWidthFixed.Floor()
lineHeight := face.Metrics().Height.Floor()
maxLinesInAtlas := atlasSizeY/lineHeight - 1
charsPerLine := atlasSizeX / charWidth
linesNeeded := int(math.Ceil(float64(len(glyphs)) / float64(charsPerLine)))
for linesNeeded > maxLinesInAtlas {
atlasSizeX *= 2
atlasSizeY *= 2
maxLinesInAtlas = atlasSizeY/lineHeight - 1
charsPerLine = atlasSizeX / charWidth
linesNeeded = int(math.Ceil(float64(len(glyphs)) / float64(charsPerLine)))
}
assert.T(atlasSizeX <= maxAtlasSize, "Atlas size went beyond maximum")
//Create atlas
atlas := &FontAtlas{
Font: f,
Img: image.NewRGBA(image.Rect(0, 0, atlasSizeX, atlasSizeY)),
Glyphs: make(map[rune]FontAtlasGlyph, len(glyphs)),
LineHeight: lineHeight,
}
//Clear background to black
draw.Draw(atlas.Img, atlas.Img.Bounds(), image.Black, image.Point{}, draw.Src)
drawer := &font.Drawer{
Dst: atlas.Img,
Src: image.White,
Face: face,
}
//Put glyphs on atlas
atlasSizeXF32 := float32(atlasSizeX)
atlasSizeYF32 := float32(atlasSizeY)
charsOnLine := 0
lineDx := fixed.P(0, lineHeight)
drawer.Dot = fixed.P(0, lineHeight)
for _, g := range glyphs {
gBounds, gAdvanceFixed, _ := face.GlyphBounds(g)
descent := gBounds.Max.Y
advanceRoundedF32 := float32(gAdvanceFixed.Floor())
ascent := -gBounds.Min.Y
heightRounded := (ascent + descent).Floor()
atlas.Glyphs[g] = FontAtlasGlyph{
U: float32(drawer.Dot.X.Floor()) / atlasSizeXF32,
V: (atlasSizeYF32 - float32((drawer.Dot.Y + descent).Floor())) / atlasSizeYF32,
SizeU: advanceRoundedF32 / atlasSizeXF32,
SizeV: float32(heightRounded) / atlasSizeYF32,
Ascent: float32(ascent.Floor()),
Descent: float32(descent.Floor()),
Advance: float32(advanceRoundedF32),
}
drawer.DrawString(string(g))
charsOnLine++
if charsOnLine == charsPerLine {
charsOnLine = 0
drawer.Dot.X = 0
drawer.Dot = drawer.Dot.Add(lineDx)
}
}
return atlas
}
func SaveImgToPNG(img image.Image, file string) error {
outFile, err := os.Create(file)
if err != nil {
return err
}
defer outFile.Close()
err = png.Encode(outFile, img)
if err != nil {
return err
}
return nil
}

297
glyphs/glyphs.go Executable file
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@ -0,0 +1,297 @@
package glyphs
import (
"math/rand"
"os"
"unicode"
"github.com/bloeys/gglm/gglm"
"github.com/bloeys/nmage/assets"
"github.com/bloeys/nmage/buffers"
"github.com/bloeys/nmage/materials"
"github.com/bloeys/nmage/meshes"
"github.com/go-gl/gl/v4.1-core/gl"
"github.com/golang/freetype/truetype"
)
type GlyphRend struct {
Atlas *FontAtlas
AtlasTex *assets.Texture
GlyphMesh *meshes.Mesh
InstancedBuf buffers.Buffer
GlyphMat *materials.Material
GlyphCount int32
GlyphVBO []float32
}
//getGlyphRanges returns a list of ranges, each range is: [i][0]<=range<[i][1]
func getGlyphRanges(f *truetype.Font) (ret [][2]rune) {
rr := [2]rune{-1, -1}
for r := rune(0); r <= unicode.MaxRune; r++ {
if privateUseArea(r) {
continue
}
if f.Index(r) == 0 {
continue
}
if rr[1] == r {
rr[1] = r + 1
continue
}
if rr[0] != -1 {
ret = append(ret, rr)
}
rr = [2]rune{r, r + 1}
}
if rr[0] != -1 {
ret = append(ret, rr)
}
return ret
}
func privateUseArea(r rune) bool {
return 0xe000 <= r && r <= 0xf8ff ||
0xf0000 <= r && r <= 0xffffd ||
0x100000 <= r && r <= 0x10fffd
}
//getGlyphsFromRanges takes ranges of runes and produces an array of all the runes in these ranges
func getGlyphsFromRanges(ranges [][2]rune) []rune {
out := make([]rune, 0)
for _, rr := range ranges {
temp := make([]rune, 0, rr[1]-rr[0])
for r := rr[0]; r < rr[1]; r++ {
temp = append(temp, r)
}
out = append(out, temp...)
}
return out
}
func (gr *GlyphRend) DrawTextOpenGL(text string, startPos *gglm.Vec3, winWidth, winHeight int32) {
//The projection matrix fits the screen size. This is needed so we can size and position characters correctly.
projMtx := gglm.Ortho(0, float32(winWidth), float32(winHeight), 0, 0.1, 10)
viewMtx := gglm.LookAt(gglm.NewVec3(0, 0, -1), gglm.NewVec3(0, 0, 0), gglm.NewVec3(0, 1, 0))
projViewMtx := projMtx.Clone().Mul(viewMtx)
gr.GlyphMat.DiffuseTex = gr.AtlasTex.TexID
gr.GlyphMat.SetUnifMat4("projViewMat", &projViewMtx.Mat4)
gr.GlyphMat.Bind()
//Prepass to pre-allocate the buffer
rs := []rune(text)
const floatsPerGlyph = 18
rCol := rand.Float32()
gCol := rand.Float32()
bCol := rand.Float32()
pos := startPos.Clone()
instancedData := make([]float32, 0, len(rs)*floatsPerGlyph) //This a larger approximation than needed because we don't count spaces etc
for i := 0; i < len(rs); i++ {
r := rs[i]
g := gr.Atlas.Glyphs[r]
if r == '\n' {
startPos.SetY(startPos.Y() - float32(gr.Atlas.LineHeight))
pos = startPos.Clone()
continue
}
gr.GlyphCount++
height := float32(g.Ascent + g.Descent)
scale := gglm.NewVec3(g.Advance, height, 1)
//See: https://developer.apple.com/library/archive/documentation/TextFonts/Conceptual/CocoaTextArchitecture/Art/glyph_metrics_2x.png
//Quads are drawn from the center and so that's our baseline. But chars shouldn't be centered, they should follow ascent/decent/advance.
//To make them do that vertically, we raise them above the baseline (y+height/2), then since they are sitting on top of the baseline we can simply
//move them down by the decent amount to put them in the correct vertical position.
//
//Horizontally the character should be drawn from the left edge not the center, so we just move it forward by advance/2
drawPos := *pos
drawPos.SetX(drawPos.X() + g.Advance*0.5)
drawPos.SetY(drawPos.Y() + height*0.5 - g.Descent)
instancedData = append(instancedData, []float32{
g.U, g.V,
g.U + g.SizeU, g.V,
g.U, g.V + g.SizeV,
g.U + g.SizeU, g.V + g.SizeV,
rCol, gCol, bCol, 1, //Color
drawPos.X(), drawPos.Y(), drawPos.Z(), //Model pos
scale.X(), scale.Y(), scale.Z(), //Model scale
}...)
pos.SetX(pos.X() + g.Advance)
}
gr.GlyphVBO = append(gr.GlyphVBO, instancedData...)
}
func (gr *GlyphRend) Draw() {
gr.InstancedBuf.SetData(gr.GlyphVBO)
gr.InstancedBuf.Bind()
gr.GlyphMat.Bind()
gl.DrawElementsInstanced(gl.TRIANGLES, gr.GlyphMesh.Buf.IndexBufCount, gl.UNSIGNED_INT, gl.PtrOffset(0), gr.GlyphCount)
gr.InstancedBuf.UnBind()
gr.GlyphCount = 0
gr.GlyphVBO = []float32{}
}
func (gr *GlyphRend) SetFace(fontOptions *truetype.Options) {
face := truetype.NewFace(gr.Atlas.Font, fontOptions)
gr.Atlas = NewFontAtlasFromFont(gr.Atlas.Font, face, uint(fontOptions.Size))
}
func (gr *GlyphRend) SetFontFromFile(fontFile string, fontOptions *truetype.Options) error {
atlas, err := NewFontAtlasFromFile(fontFile, fontOptions)
if err != nil {
return err
}
gr.Atlas = atlas
return nil
}
func NewGlyphRend(fontFile string, fontOptions *truetype.Options) (*GlyphRend, error) {
atlas, err := NewFontAtlasFromFile(fontFile, fontOptions)
if err != nil {
return nil, err
}
//Create OpenGL texture
pngFileName := fontFile + "atlas.png"
err = SaveImgToPNG(atlas.Img, pngFileName)
if err != nil {
return nil, err
}
atlasTex, err := assets.LoadPNGTexture(pngFileName)
if err != nil {
return nil, err
}
os.Remove(pngFileName)
gl.BindTexture(gl.TEXTURE_2D, atlasTex.TexID)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.BindTexture(gl.TEXTURE_2D, 0)
//Create glyph mesh
glyphMesh := &meshes.Mesh{
Name: "glypQuad",
//VertPos, UV, Color; Instanced attributes are stored separately
Buf: buffers.NewBuffer(
buffers.Element{ElementType: buffers.DataTypeVec3},
),
}
glyphMesh.Buf.SetData([]float32{
-0.5, -0.5, 0,
0.5, -0.5, 0,
-0.5, 0.5, 0,
0.5, 0.5, 0,
})
glyphMesh.Buf.SetIndexBufData([]uint32{
0, 1, 2,
1, 3, 2,
})
//Setup material
glyphMat := materials.NewMaterial("glyphMat", "./res/shaders/glyph")
glyphMat.SetAttribute(glyphMesh.Buf)
//Create instanced buf and set its instanced attributes.
//Multiple VBOs under one VAO, one VBO for vertex data, and one VBO for instanced data.
instancedBuf := buffers.Buffer{
VAOID: glyphMesh.Buf.VAOID,
}
instancedBuf.SetLayout(
buffers.Element{ElementType: buffers.DataTypeVec2}, //UVST0
buffers.Element{ElementType: buffers.DataTypeVec2}, //UVST1
buffers.Element{ElementType: buffers.DataTypeVec2}, //UVST2
buffers.Element{ElementType: buffers.DataTypeVec2}, //UVST3
buffers.Element{ElementType: buffers.DataTypeVec4}, //Color
buffers.Element{ElementType: buffers.DataTypeVec3}, //ModelPos
buffers.Element{ElementType: buffers.DataTypeVec3}, //ModelScale
)
gl.GenBuffers(1, &instancedBuf.BufID)
if instancedBuf.BufID == 0 {
panic("Failed to create openGL buffer")
}
instancedBuf.Bind()
gl.BindBuffer(gl.ARRAY_BUFFER, instancedBuf.BufID)
layout := instancedBuf.GetLayout()
//4 UV values
uvEle := layout[0]
gl.EnableVertexAttribArray(1)
gl.VertexAttribPointer(1, uvEle.ElementType.CompCount(), uvEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(uvEle.Offset))
gl.VertexAttribDivisor(1, 1)
uvEle = layout[1]
gl.EnableVertexAttribArray(2)
gl.VertexAttribPointer(2, uvEle.ElementType.CompCount(), uvEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(uvEle.Offset))
gl.VertexAttribDivisor(2, 1)
uvEle = layout[2]
gl.EnableVertexAttribArray(3)
gl.VertexAttribPointer(3, uvEle.ElementType.CompCount(), uvEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(uvEle.Offset))
gl.VertexAttribDivisor(3, 1)
uvEle = layout[3]
gl.EnableVertexAttribArray(4)
gl.VertexAttribPointer(4, uvEle.ElementType.CompCount(), uvEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(uvEle.Offset))
gl.VertexAttribDivisor(4, 1)
//Rest of instanced attributes
colorEle := layout[4]
gl.EnableVertexAttribArray(5)
gl.VertexAttribPointer(5, colorEle.ElementType.CompCount(), colorEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(colorEle.Offset))
gl.VertexAttribDivisor(5, 1)
posEle := layout[5]
gl.EnableVertexAttribArray(6)
gl.VertexAttribPointer(6, posEle.ElementType.CompCount(), posEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(posEle.Offset))
gl.VertexAttribDivisor(6, 1)
scaleEle := layout[6]
gl.EnableVertexAttribArray(7)
gl.VertexAttribPointer(7, scaleEle.ElementType.CompCount(), scaleEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(scaleEle.Offset))
gl.VertexAttribDivisor(7, 1)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
instancedBuf.UnBind()
return &GlyphRend{
Atlas: atlas,
AtlasTex: &atlasTex,
GlyphMesh: glyphMesh,
InstancedBuf: instancedBuf,
GlyphMat: glyphMat,
GlyphCount: 0,
GlyphVBO: make([]float32, 0),
}, nil
}

515
main.go
View File

@ -2,31 +2,17 @@ package main
import (
"fmt"
"image"
"image/draw"
"image/png"
"math"
"math/rand"
"os"
"sync"
"time"
"unicode"
"github.com/bloeys/gglm/gglm"
"github.com/bloeys/nmage/assets"
"github.com/bloeys/nmage/buffers"
"github.com/bloeys/nmage/engine"
"github.com/bloeys/nmage/input"
"github.com/bloeys/nmage/materials"
"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/go-gl/gl/v4.1-core/gl"
"github.com/bloeys/nterm/glyphs"
"github.com/golang/freetype/truetype"
"github.com/veandco/go-sdl2/sdl"
"golang.org/x/image/font"
"golang.org/x/image/math/fixed"
)
var _ engine.Game = &program{}
@ -39,9 +25,11 @@ type program struct {
}
//nMage TODO:
//* Assert that engine is inited
//* Create VAO struct independent from VBO to support multi-VBO use cases (e.g. instancing)
//* Move SetAttribute away from material struct
// * Assert that engine is inited
// * Create VAO struct independent from VBO to support multi-VBO use cases (e.g. instancing)
// * Move SetAttribute away from material struct
// * Fix FPS counter
// * Allow texture loading without cache
func main() {
@ -68,158 +56,16 @@ func main() {
engine.Run(p)
}
type FontTexAtlas struct {
Img *image.RGBA
Glyphs map[rune]FontTexAtlasGlyph
LineHeight int
}
type FontTexAtlasGlyph struct {
U float32
V float32
SizeU float32
SizeV float32
Ascent float32
Descent float32
Advance float32
}
var fontPointSize uint = 32
var atlas *FontTexAtlas
var atlasTex assets.Texture
var glyphRend *GlyphRend
var glyphRend *glyphs.GlyphRend
func (p *program) Init() {
var err error
atlas, err = createAtlasFromFontFile("./res/fonts/Consolas.ttf", &truetype.Options{Size: float64(fontPointSize), DPI: 72})
glyphRend, err = glyphs.NewGlyphRend("./res/fonts/Consolas.ttf", &truetype.Options{Size: float64(fontPointSize), DPI: 72})
if err != nil {
panic("Failed to create atlas from font file. Err: " + err.Error())
}
glyphRend = NewGlyphRend()
}
func createAtlasFromFontFile(fontFile string, faceOptions *truetype.Options) (*FontTexAtlas, error) {
fBytes, err := os.ReadFile(fontFile)
if err != nil {
return nil, err
}
f, err := truetype.Parse(fBytes)
if err != nil {
return nil, err
}
face := truetype.NewFace(f, faceOptions)
atlas := genTextureAtlasFromFace(f, face, uint(faceOptions.Size))
return atlas, nil
}
func genTextureAtlasFromFace(f *truetype.Font, face font.Face, pointSize uint) *FontTexAtlas {
const maxAtlasSize = 8192
glyphs := getGlyphsFromRanges(getGlyphRanges(f))
assert.T(len(glyphs) > 0, "no glyphs")
//Choose atlas size
atlasSizeX := 512
atlasSizeY := 512
_, charWidthFixed, _ := face.GlyphBounds(glyphs[0])
charWidth := charWidthFixed.Floor()
lineHeight := face.Metrics().Height.Floor()
maxLinesInAtlas := atlasSizeY/lineHeight - 1
charsPerLine := atlasSizeX / charWidth
linesNeeded := int(math.Ceil(float64(len(glyphs)) / float64(charsPerLine)))
for linesNeeded > maxLinesInAtlas {
atlasSizeX *= 2
atlasSizeY *= 2
maxLinesInAtlas = atlasSizeY/lineHeight - 1
charsPerLine = atlasSizeX / charWidth
linesNeeded = int(math.Ceil(float64(len(glyphs)) / float64(charsPerLine)))
}
assert.T(atlasSizeX <= maxAtlasSize, "Atlas size went beyond maximum")
//Create atlas
atlas := &FontTexAtlas{
Img: image.NewRGBA(image.Rect(0, 0, atlasSizeX, atlasSizeY)),
Glyphs: make(map[rune]FontTexAtlasGlyph, len(glyphs)),
LineHeight: lineHeight,
}
//Clear background to black
draw.Draw(atlas.Img, atlas.Img.Bounds(), image.Black, image.Point{}, draw.Src)
drawer := &font.Drawer{
Dst: atlas.Img,
Src: image.White,
Face: face,
}
//Put glyphs on atlas
charsOnLine := 0
lineDx := fixed.P(0, lineHeight)
drawer.Dot = fixed.P(0, lineHeight)
for _, g := range glyphs {
gBounds, gAdvanceFixed, _ := face.GlyphBounds(g)
descent := gBounds.Max.Y
advanceRounded := gAdvanceFixed.Floor()
ascent := -gBounds.Min.Y
heightRounded := (ascent + descent).Floor()
atlas.Glyphs[g] = FontTexAtlasGlyph{
U: float32(drawer.Dot.X.Floor()) / float32(atlasSizeX),
V: (float32(atlasSizeY-(drawer.Dot.Y+descent).Floor()) / float32(atlasSizeY)),
SizeU: float32(advanceRounded) / float32(atlasSizeX),
SizeV: (float32(heightRounded) / float32(atlasSizeY)),
Ascent: float32(ascent.Floor()),
Descent: float32(descent.Floor()),
Advance: float32(advanceRounded),
}
drawer.DrawString(string(g))
charsOnLine++
if charsOnLine == charsPerLine {
charsOnLine = 0
drawer.Dot.X = 0
drawer.Dot = drawer.Dot.Add(lineDx)
}
}
// fmt.Println(atlas.Glyphs)
saveImgToDisk(atlas.Img, "atlas.png")
return atlas
}
func saveImgToDisk(img image.Image, file string) {
outFile, err := os.Create(file)
if err != nil {
panic(err)
}
defer outFile.Close()
err = png.Encode(outFile, img)
if err != nil {
panic(err)
}
}
func (p *program) Start() {
@ -239,39 +85,17 @@ func (p *program) Update() {
p.shouldRun = false
}
fontSizeChanged := false
if input.KeyClicked(sdl.K_KP_PLUS) {
fontPointSize += 2
var err error
atlas, err = createAtlasFromFontFile("./res/fonts/Consolas.ttf", &truetype.Options{Size: float64(fontPointSize), DPI: 72})
if err != nil {
panic("Failed to create atlas from font file. Err: " + err.Error())
}
//Delete old opengl texture
gl.DeleteTextures(1, &atlasTex.TexID)
delete(assets.TexturePaths, "./res/fonts/Consolas.ttf")
delete(assets.Textures, atlasTex.TexID)
atlasTex.TexID = 0
fontSizeChanged = true
} else if input.KeyClicked(sdl.K_KP_MINUS) {
fontPointSize -= 2
fontSizeChanged = true
}
if input.KeyClicked(sdl.K_KP_MINUS) {
fontPointSize -= 2
var err error
atlas, err = createAtlasFromFontFile("./res/fonts/Consolas.ttf", &truetype.Options{Size: float64(fontPointSize), DPI: 72})
if err != nil {
panic("Failed to create atlas from font file. Err: " + err.Error())
}
//Delete old opengl texture
gl.DeleteTextures(1, &atlasTex.TexID)
delete(assets.TexturePaths, "./res/fonts/Consolas.ttf")
delete(assets.Textures, atlasTex.TexID)
atlasTex.TexID = 0
if fontSizeChanged {
glyphRend.SetFace(&truetype.Options{Size: float64(fontPointSize), DPI: 72})
}
}
@ -286,22 +110,22 @@ func (p *program) Render() {
if frameTime.Milliseconds() > 0 {
fps = 1 / float32(frameTime.Milliseconds()) * 1000
}
startFromTop := float32(h) - float32(atlas.LineHeight)
glyphRend.drawTextOpenGL(atlas, fmt.Sprintf("FPS=%f", fps), gglm.NewVec3(float32(w)*0.7, startFromTop, 0), w, h)
startFromTop := float32(h) - float32(glyphRend.Atlas.LineHeight)
glyphRend.DrawTextOpenGL(fmt.Sprintf("FPS=%f", fps), gglm.NewVec3(float32(w)*0.7, startFromTop, 0), w, h)
//Draw point and texture sizes
startFromTop -= float32(atlas.LineHeight)
glyphRend.drawTextOpenGL(atlas, fmt.Sprintf("Point size=%d", fontPointSize), gglm.NewVec3(float32(w)*0.7, startFromTop, 0), w, h)
startFromTop -= float32(glyphRend.Atlas.LineHeight)
glyphRend.DrawTextOpenGL(fmt.Sprintf("Point size=%d", fontPointSize), gglm.NewVec3(float32(w)*0.7, startFromTop, 0), w, h)
startFromTop -= float32(atlas.LineHeight)
glyphRend.drawTextOpenGL(atlas, fmt.Sprintf("Texture size=%d*%d", atlasTex.Width, atlasTex.Height), gglm.NewVec3(float32(w)*0.7, startFromTop, 0), w, h)
startFromTop -= float32(glyphRend.Atlas.LineHeight)
glyphRend.DrawTextOpenGL(fmt.Sprintf("Texture size=%d*%d", glyphRend.Atlas.Img.Rect.Max.X, glyphRend.Atlas.Img.Rect.Max.Y), gglm.NewVec3(float32(w)*0.7, startFromTop, 0), w, h)
//Draw all other
count := 1000
startFromBot := float32(atlas.LineHeight)
startFromBot := float32(glyphRend.Atlas.LineHeight)
for i := 0; i < count; i++ {
glyphRend.drawTextOpenGL(atlas, "Hello friend, how are you?\n", gglm.NewVec3(0, startFromBot, 0), w, h)
startFromBot += float32(atlas.LineHeight) * 2
glyphRend.DrawTextOpenGL("Hello friend, how are you?\n", gglm.NewVec3(0, startFromBot, 0), w, h)
startFromBot += float32(glyphRend.Atlas.LineHeight) * 2
}
gg.Do(func() {
@ -330,294 +154,3 @@ func (p *program) ShouldRun() bool {
func (p *program) Deinit() {
}
//getGlyphRanges returns a list of ranges, each range is: [i][0]<=range<[i][1]
func getGlyphRanges(f *truetype.Font) (ret [][2]rune) {
rr := [2]rune{-1, -1}
for r := rune(0); r <= unicode.MaxRune; r++ {
if privateUseArea(r) {
continue
}
if f.Index(r) == 0 {
continue
}
if rr[1] == r {
rr[1] = r + 1
continue
}
if rr[0] != -1 {
ret = append(ret, rr)
}
rr = [2]rune{r, r + 1}
}
if rr[0] != -1 {
ret = append(ret, rr)
}
return ret
}
func privateUseArea(r rune) bool {
return 0xe000 <= r && r <= 0xf8ff ||
0xf0000 <= r && r <= 0xffffd ||
0x100000 <= r && r <= 0x10fffd
}
//getGlyphsFromRanges takes ranges of runes and produces an array of all the runes in these ranges
func getGlyphsFromRanges(ranges [][2]rune) []rune {
out := make([]rune, 0)
for _, rr := range ranges {
temp := make([]rune, 0, rr[1]-rr[0])
for r := rr[0]; r < rr[1]; r++ {
temp = append(temp, r)
}
out = append(out, temp...)
}
return out
}
var glyphMat *materials.Material
func (gr *GlyphRend) drawTextOpenGL(atlas *FontTexAtlas, text string, startPos *gglm.Vec3, winWidth, winHeight int32) {
// if glyphMesh == nil {
// glyphMesh = &meshes.Mesh{
// Name: "glypQuad",
// //VertPos, UV, Color
// Buf: buffers.NewBuffer(
// buffers.Element{ElementType: buffers.DataTypeVec3},
// buffers.Element{ElementType: buffers.DataTypeVec2},
// buffers.Element{ElementType: buffers.DataTypeVec4},
// ),
// }
// glyphMesh.Buf.SetData([]float32{
// -0.5, -0.5, 0,
// 0, 0,
// 1, 1, 1, 1,
// 0.5, -0.5, 0,
// 1, 0,
// 1, 1, 1, 1,
// -0.5, 0.5, 0,
// 0, 1,
// 1, 1, 1, 1,
// 0.5, 0.5, 0,
// 1, 1,
// 1, 1, 1, 1,
// })
// glyphMesh.Buf.SetIndexBufData([]uint32{
// 0, 1, 2,
// 1, 3, 2,
// })
// }
if glyphMat == nil {
glyphMat = materials.NewMaterial("glyphMat", "./res/shaders/glyph")
}
if atlasTex.TexID == 0 {
var err error
atlasTex, err = assets.LoadPNGTexture("./atlas.png")
if err != nil {
panic(err.Error())
}
gl.BindTexture(gl.TEXTURE_2D, atlasTex.TexID)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.BindTexture(gl.TEXTURE_2D, 0)
}
//Prepare to draw
// glyphMesh.Buf.Bind()
//The projection matrix fits the screen size. This is needed so we can size and position characters correctly.
projMtx := gglm.Ortho(0, float32(winWidth), float32(winHeight), 0, 0.1, 10)
viewMtx := gglm.LookAt(gglm.NewVec3(0, 0, -1), gglm.NewVec3(0, 0, 0), gglm.NewVec3(0, 1, 0))
projViewMtx := projMtx.Clone().Mul(viewMtx)
glyphMat.DiffuseTex = atlasTex.TexID
glyphMat.SetUnifMat4("projViewMat", &projViewMtx.Mat4)
glyphMat.Bind()
//Prepass to pre-allocate the buffer
rs := []rune(text)
const floatsPerGlyph = 18
rCol := rand.Float32()
gCol := rand.Float32()
bCol := rand.Float32()
pos := startPos.Clone()
instancedData := make([]float32, 0, len(rs)*floatsPerGlyph) //This a larger approximation than needed because we don't count spaces etc
for i := 0; i < len(rs); i++ {
r := rs[i]
g := atlas.Glyphs[r]
if r == '\n' {
startPos.SetY(startPos.Y() - float32(atlas.LineHeight))
pos = startPos.Clone()
continue
}
gr.GlyphCount++
height := float32(g.Ascent + g.Descent)
scale := gglm.NewVec3(g.Advance, height, 1)
//See: https://developer.apple.com/library/archive/documentation/TextFonts/Conceptual/CocoaTextArchitecture/Art/glyph_metrics_2x.png
//Quads are drawn from the center and so that's our baseline. But chars shouldn't be centered, they should follow ascent/decent/advance.
//To make them do that vertically, we raise them above the baseline (y+height/2), then since they are sitting on top of the baseline we can simply
//move them down by the decent amount to put them in the correct vertical position.
//
//Horizontally the character should be drawn from the left edge not the center, so we just move it forward by advance/2
drawPos := *pos
drawPos.SetX(drawPos.X() + g.Advance*0.5)
drawPos.SetY(drawPos.Y() + height*0.5 - g.Descent)
instancedData = append(instancedData, []float32{
g.U, g.V,
g.U + g.SizeU, g.V,
g.U, g.V + g.SizeV,
g.U + g.SizeU, g.V + g.SizeV,
rCol, gCol, bCol, 1, //Color
drawPos.X(), drawPos.Y(), drawPos.Z(), //Model pos
scale.X(), scale.Y(), scale.Z(), //Model scale
}...)
pos.SetX(pos.X() + g.Advance)
}
gr.GlyphVBO = append(gr.GlyphVBO, instancedData...)
}
type GlyphRend struct {
InstancedBuf buffers.Buffer
GlyphMesh *meshes.Mesh
GlyphCount int32
GlyphVBO []float32
}
func (gr *GlyphRend) Draw() {
gr.InstancedBuf.SetData(gr.GlyphVBO)
gr.InstancedBuf.Bind()
glyphMat.Bind()
// gl.DrawElements(gl.TRIANGLES, mesh.Buf.IndexBufCount, gl.UNSIGNED_INT, gl.PtrOffset(0))
gl.DrawElementsInstanced(gl.TRIANGLES, gr.GlyphMesh.Buf.IndexBufCount, gl.UNSIGNED_INT, gl.PtrOffset(0), gr.GlyphCount)
gr.InstancedBuf.UnBind()
gr.GlyphCount = 0
gr.GlyphVBO = []float32{}
}
func NewGlyphRend() *GlyphRend {
//Create glyph mesh
glyphMesh := &meshes.Mesh{
Name: "glypQuad",
//VertPos, UV, Color; Instanced attributes are stored separately
Buf: buffers.NewBuffer(
buffers.Element{ElementType: buffers.DataTypeVec3},
),
}
glyphMesh.Buf.SetData([]float32{
-0.5, -0.5, 0,
0.5, -0.5, 0,
-0.5, 0.5, 0,
0.5, 0.5, 0,
})
glyphMesh.Buf.SetIndexBufData([]uint32{
0, 1, 2,
1, 3, 2,
})
(*materials.Material).SetAttribute(nil, glyphMesh.Buf)
//Create instanced buf and set its instanced attributes.
//Multiple VBOs under one VAO, one VBO for vertex data, and one VBO for instanced data.
instancedBuf := buffers.Buffer{
VAOID: glyphMesh.Buf.VAOID,
}
instancedBuf.SetLayout(
buffers.Element{ElementType: buffers.DataTypeVec2}, //UVST0
buffers.Element{ElementType: buffers.DataTypeVec2}, //UVST1
buffers.Element{ElementType: buffers.DataTypeVec2}, //UVST2
buffers.Element{ElementType: buffers.DataTypeVec2}, //UVST3
buffers.Element{ElementType: buffers.DataTypeVec4}, //Color
buffers.Element{ElementType: buffers.DataTypeVec3}, //ModelPos
buffers.Element{ElementType: buffers.DataTypeVec3}, //ModelScale
)
gl.GenBuffers(1, &instancedBuf.BufID)
if instancedBuf.BufID == 0 {
panic("Failed to create openGL buffer")
}
instancedBuf.Bind()
gl.BindBuffer(gl.ARRAY_BUFFER, instancedBuf.BufID)
layout := instancedBuf.GetLayout()
//4 UV values
uvEle := layout[0]
gl.EnableVertexAttribArray(1)
gl.VertexAttribPointer(1, uvEle.ElementType.CompCount(), uvEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(uvEle.Offset))
gl.VertexAttribDivisor(1, 1)
uvEle = layout[1]
gl.EnableVertexAttribArray(2)
gl.VertexAttribPointer(2, uvEle.ElementType.CompCount(), uvEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(uvEle.Offset))
gl.VertexAttribDivisor(2, 1)
uvEle = layout[2]
gl.EnableVertexAttribArray(3)
gl.VertexAttribPointer(3, uvEle.ElementType.CompCount(), uvEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(uvEle.Offset))
gl.VertexAttribDivisor(3, 1)
uvEle = layout[3]
gl.EnableVertexAttribArray(4)
gl.VertexAttribPointer(4, uvEle.ElementType.CompCount(), uvEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(uvEle.Offset))
gl.VertexAttribDivisor(4, 1)
//Rest of instanced attributes
colorEle := layout[4]
gl.EnableVertexAttribArray(5)
gl.VertexAttribPointer(5, colorEle.ElementType.CompCount(), colorEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(colorEle.Offset))
gl.VertexAttribDivisor(5, 1)
posEle := layout[5]
gl.EnableVertexAttribArray(6)
gl.VertexAttribPointer(6, posEle.ElementType.CompCount(), posEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(posEle.Offset))
gl.VertexAttribDivisor(6, 1)
scaleEle := layout[6]
gl.EnableVertexAttribArray(7)
gl.VertexAttribPointer(7, scaleEle.ElementType.CompCount(), scaleEle.ElementType.GLType(), false, instancedBuf.Stride, gl.PtrOffset(scaleEle.Offset))
gl.VertexAttribDivisor(7, 1)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
instancedBuf.UnBind()
return &GlyphRend{
GlyphMesh: glyphMesh,
InstancedBuf: instancedBuf,
GlyphCount: 0,
GlyphVBO: make([]float32, 0),
}
}