AllenDang
[bug] crashes when changing texture on a canvas (DeleteTexture / segmentation violation)
What happend?
This is possibly related to #854 and #819, but the issue still persists for me even with the latest commits:
- giu v0.9.1-0.20241007062706-7bbbc0c51774
- cimgui-go v1.0.3-0.20241007063847-1a15ba4f9967
I made a custom widget that displays a map with a bunch of countries. When I click some country, it gets highlighted and it shows in the UI. I made this using an image mask that has the countries colored with different colors, and when I click on the widget - it gets the pixel color of the clicked country at the (X, Y) and then generates a new image with the highlighted area.
After changing the displayed image a couple of times, the app crashes:
Log & stacktrace
GetCurrentTexture(): NewTextureFromRgba id={4}
GetCurrentTexture(): done, returning new texture
GetCurrentTexture(): 1) cloning image
GetCurrentTexture(): 2) creating mask
GetCurrentTexture(): 3) converting to draw.Image
GetCurrentTexture(): 4) drawing mask
GetCurrentTexture(): 5) converting back to image.Image
GetCurrentTexture(): 6) mask applied, generating texture
GetCurrentTexture(): NewTextureFromRgba id={5}
GetCurrentTexture(): done, returning new texture
GetCurrentTexture(): 1) cloning image
GetCurrentTexture(): 2) creating mask
backend/texture.go: Texture.release() -> DeleteTexture({4})
SIGSEGV: segmentation violation
PC=0x1f5bbc8f8 m=9 sigcode=2 addr=0x30
signal arrived during cgo execution
goroutine 34 gp=0x14000186380 m=9 mp=0x1400008c808 [syscall]:
runtime.cgocall(0x1006eca48, 0x14000068ca8)
/opt/homebrew/Cellar/go/1.23.2/libexec/src/runtime/cgocall.go:167 +0x44 fp=0x14000068c70 sp=0x14000068c30 pc=0x1005bba44
github.com/AllenDang/cimgui-go/backend/glfwbackend._Cfunc_igDeleteTexture(0x4)
_cgo_gotypes.go:388 +0x30 fp=0x14000068ca0 sp=0x14000068c70 pc=0x1006350a0
github.com/AllenDang/cimgui-go/backend/glfwbackend.(*GLFWBackend).DeleteTexture.func1({0x1400023c0d0?})
~/go/pkg/mod/github.com/!allen!dang/[email protected]/backend/glfwbackend/glfw_backend.go:375 +0x40 fp=0x14000068ce0 sp=0x14000068ca0 pc=0x100635ee0
github.com/AllenDang/cimgui-go/backend/glfwbackend.(*GLFWBackend).DeleteTexture(0x100a9b348?, {0x1400019c018?})
~/go/pkg/mod/github.com/!allen!dang/[email protected]/backend/glfwbackend/glfw_backend.go:375 +0x20 fp=0x14000068d00 sp=0x14000068ce0 pc=0x100635e70
github.com/AllenDang/cimgui-go/backend.(*Texture).release(0x1400001c2a0)
~/go/pkg/mod/github.com/!allen!dang/[email protected]/backend/texture.go:39 +0x98 fp=0x14000068d60 sp=0x14000068d00 pc=0x1006347b8
runtime.call16(0x0, 0x100a9a198, 0x140005c4000, 0x10, 0x10, 0x10, 0x14000068e00)
/opt/homebrew/Cellar/go/1.23.2/libexec/src/runtime/asm_arm64.s:504 +0x78 fp=0x14000068d80 sp=0x14000068d60 pc=0x1005c6838
runtime.runfinq()
/opt/homebrew/Cellar/go/1.23.2/libexec/src/runtime/mfinal.go:255 +0x3e4 fp=0x14000068fd0 sp=0x14000068d80 pc=0x10056bea4
runtime.goexit({})
/opt/homebrew/Cellar/go/1.23.2/libexec/src/runtime/asm_arm64.s:1223 +0x4 fp=0x14000068fd0 sp=0x14000068fd0 pc=0x1005c8834
created by runtime.createfing in goroutine 1
/opt/homebrew/Cellar/go/1.23.2/libexec/src/runtime/mfinal.go:163 +0x80
I tried to debug/refactor it with no success; didn't have this issue on giu v0.7.0.
Code example
main.go
package main
import (
"fmt"
"image"
"image/color"
"image/draw"
"os"
"slices"
"strings"
"github.com/AllenDang/cimgui-go/imgui"
g "github.com/AllenDang/giu"
)
var (
europe *MapWidget
)
type MapWidget struct {
img_w float32
img_h float32
img_size image.Point
current_texture *g.Texture
should_refresh bool
i_texture *g.Texture
i_image *image.Image
i_highlighted *image.RGBA
i_area *image.RGBA
palette map[color.Color]int
palette_int map[int]color.Color
selected_area_ids []int
}
func NewMapWidget() *MapWidget {
return &MapWidget{}
}
func (m *MapWidget) Init() {
fmt.Printf("Init()\n")
m.palette = map[color.Color]int{}
m.palette_int = map[int]color.Color{}
m.img_w = float32(512)
m.img_h = float32(512)
m.img_size = image.Pt(512, 512)
m.selected_area_ids = []int{}
m.should_refresh = true
m.LoadPalette()
m.LoadImage("")
m.LoadImage("highlighted")
m.LoadImage("areas")
}
func (m *MapWidget) LoadPalette() {
img_palette, _ := g.LoadImage("images/palette.png")
for x := range 24 {
col := img_palette.At(x, 0)
m.palette[col] = x + 1
m.palette_int[x+1] = color.RGBAModel.Convert(col)
}
fmt.Println()
}
func (m *MapWidget) LoadImage(suffix string) {
path := fmt.Sprintf("images/map.png")
if suffix == "" {
img, _ := open_image_file(path)
m.i_image = &img
fmt.Printf("i_image loaded: ptr=%v\n", m.i_image)
} else if suffix == "highlighted" {
path = strings.Replace(path, ".png", "_highlighted.png", 1)
img, _ := open_image_file(path)
m.i_highlighted = g.ImageToRgba(img)
fmt.Printf("i_highlighted loaded: ptr=%v\n", m.i_image)
} else if suffix == "areas" {
path = strings.Replace(path, ".png", "_areas.png", 1)
img, _ := open_image_file(path)
m.i_area = g.ImageToRgba(img)
fmt.Printf("i_area loaded: ptr=%v\n", m.i_image)
}
}
func (m *MapWidget) LoadTexture() {
path := fmt.Sprintf("images/map.png")
i, _ := g.LoadImage(path)
g.NewTextureFromRgba(i, func(tex *g.Texture) {
fmt.Printf("LoadTexture(): NewTextureFromRgba id=%v\n", tex.ID())
m.i_texture = tex
m.current_texture = tex
})
}
func (m *MapWidget) ToggleSelectAreaID(area_id int) {
if area_id == 0 {
return
}
if slices.Contains(m.selected_area_ids, area_id) {
m.selected_area_ids = slices.DeleteFunc(m.selected_area_ids, func(e int) bool { return e == area_id })
} else {
m.selected_area_ids = append(m.selected_area_ids, area_id)
}
m.should_refresh = true
}
func (m *MapWidget) clonePix(b []uint8) []byte {
// https://groups.google.com/g/golang-nuts/c/pic3Nya7DRg
c := make([]uint8, len(b))
copy(c, b)
return c
}
func (m *MapWidget) CloneImage(src image.Image) draw.Image {
// https://groups.google.com/g/golang-nuts/c/pic3Nya7DRg
switch s := src.(type) {
case *image.Alpha:
clone := *s
clone.Pix = m.clonePix(s.Pix)
return &clone
case *image.Alpha16:
clone := *s
clone.Pix = m.clonePix(s.Pix)
return &clone
case *image.Gray:
clone := *s
clone.Pix = m.clonePix(s.Pix)
return &clone
case *image.Gray16:
clone := *s
clone.Pix = m.clonePix(s.Pix)
return &clone
case *image.NRGBA:
clone := *s
clone.Pix = m.clonePix(s.Pix)
return &clone
case *image.NRGBA64:
clone := *s
clone.Pix = m.clonePix(s.Pix)
return &clone
case *image.RGBA:
clone := *s
clone.Pix = m.clonePix(s.Pix)
return &clone
case *image.RGBA64:
clone := *s
clone.Pix = m.clonePix(s.Pix)
return &clone
}
return nil
}
func (m *MapWidget) CreateMask(img image.Image) image.Image {
black := color.RGBA{0, 0, 0, 0}
white := color.RGBA{255, 0, 255, 255}
var cols []color.Color
for _, area_id := range m.selected_area_ids {
cols = append(cols, m.palette_int[int(area_id)])
}
b := img.Bounds()
img_new := image.NewRGBA(b)
for y := 0; y < b.Max.Y; y++ {
for x := 0; x < b.Max.X; x++ {
px_col := img.At(x, y)
px_col_rgba := color.RGBAModel.Convert(px_col)
if slices.Contains(cols, px_col_rgba) {
img_new.Set(x, y, white)
} else {
img_new.Set(x, y, black)
}
}
}
return img_new
}
func (m *MapWidget) GetCurrentTexture() *g.Texture {
if m.should_refresh {
fmt.Printf("GetCurrentTexture(): 1) cloning image\n")
img := m.CloneImage(*m.i_image)
img_highlighted := m.i_highlighted
img_area := m.i_area
fmt.Printf("GetCurrentTexture(): 2) creating mask\n")
img_mask := m.CreateMask(img_area)
fmt.Printf("GetCurrentTexture(): 3) converting to draw.Image\n")
img_final, _ := img.(draw.Image)
fmt.Printf("GetCurrentTexture(): 4) drawing mask\n")
draw.DrawMask(img_final, img.Bounds(), img_highlighted, image.Point{0, 0}, img_mask, img_mask.Bounds().Min, draw.Over)
fmt.Printf("GetCurrentTexture(): 5) converting back to image.Image\n")
img_final_image := img_final.(image.Image)
fmt.Printf("GetCurrentTexture(): 6) mask applied, generating texture\n")
g.NewTextureFromRgba(img_final_image, func(tex *g.Texture) {
fmt.Printf("GetCurrentTexture(): NewTextureFromRgba id=%v\n", tex.ID())
m.current_texture = tex
})
m.should_refresh = false
fmt.Printf("GetCurrentTexture(): done, returning new texture\n")
}
return m.current_texture
}
func (m *MapWidget) Widget() *g.CustomWidget {
return g.Custom(func() {
canvas := g.GetCanvas()
start_pos := g.GetCursorScreenPos()
end_pos := start_pos.Add(m.img_size)
id_str := g.GenAutoID("canvas_invisible_button").String()
// fmt.Printf("[Widget()] id=%s\n", id_str)
imgui.InvisibleButton(id_str, imgui.Vec2{X: float32(m.img_w), Y: float32(m.img_h)})
if m.i_texture == nil {
fmt.Printf("Widget(): loading texture\n")
m.LoadTexture()
} else {
// fmt.Printf("Widget(): getting current texture\n")
cur_tex := m.GetCurrentTexture()
// fmt.Printf("Widget(): cur_tex=%v, adding image to canvas\n", cur_tex)
canvas.AddImage(cur_tex, start_pos, end_pos)
}
if g.IsMouseClicked(g.MouseButtonLeft) && g.IsWindowFocused(0) {
mouse_pos := g.GetMousePos()
rel_mouse_pos := mouse_pos.Sub(start_pos)
if rel_mouse_pos.X >= 0 && rel_mouse_pos.X < m.img_size.X && rel_mouse_pos.Y >= 0 && rel_mouse_pos.Y < m.img_size.Y {
mask_color := m.i_area.At(rel_mouse_pos.X, rel_mouse_pos.Y)
area_id := m.palette[mask_color]
m.ToggleSelectAreaID(area_id)
}
}
})
}
func loop() {
map_thumbnail := europe.Widget()
g.SingleWindow().Layout(
g.Label("dummy label"),
map_thumbnail,
)
}
func open_image_file(filepath string) (image.Image, error) {
f, err := os.Open(filepath)
if err != nil {
fmt.Printf("open_image_file open err: %v\n", err)
return nil, err
}
defer f.Close()
img, _, err := image.Decode(f)
if err != nil {
fmt.Printf("open_image_file decode err: %v\n", err)
return nil, err
}
return img, nil
}
func main() {
europe = NewMapWidget()
europe.Init()
wnd := g.NewMasterWindow("Canvas", 600, 600, 0)
wnd.Run(loop)
}
To Reproduce
Put these images in the "images" directory (relative to main.go):
map_areas.png: https://github.com/user-attachments/assets/a5c3b998-aaff-4257-9fcc-ca59b8517b26
map.png: https://github.com/user-attachments/assets/dd4aacb1-785c-416c-bbcd-18a8f155997c
map_highlighted.png: https://github.com/user-attachments/assets/e8b974fe-2789-446d-983d-dc23e585ff57
palette.png https://github.com/user-attachments/assets/653203e3-d09a-4d47-817b-bd7a9a22e297
Run the main.go and try clicking on a several countries.
Version
master
OS
darwin / arm64 (macOS 14.6.1)
I'm sorry, I seem to have fixed it.
Just noticed the new examples (asyncimage.go specifically) that use ReflectiveBoundTexture, so I rewrote my code by replacing g.Texture with g.ReflectiveBoundTexture.
(also, g.NewTextureFromRgba() -> rb_texture.SetSurfaceFromRGBA())
(and now I'm using rb_texture.Texture()to put it on the canvas).
@ioxenus if you use ReflectiveBoundTexture please use master branch, not 0.9.0 release as it contains important fixe to avoid double freeing texture against glfw (see https://github.com/AllenDang/giu/commit/1f8aaafc321c69e8f5515ea6db7b93c6df453490#diff-7771525abe6cc9f582453f4e0b2c6ad87be391fd8b3cb6743c9a5d04d5be90b2)
Yeah, I use the master branch, thanks!
After fixing my own custom widget, I noticed that it still crashes. Turned out I was still using the g.ImageWithRgba widget somewhere else. Managed to fix that, too, by adding ReflectiveBoundTexture (with SetSurfaceFromRGBA) and using tex.ToImageWidget() instead of g.ImageWithRgba()
before:
var img_icon image.Image
// load image from file (skipping error handling just for the sake of readability)
f, _ := embed_fs.Open("icon.png")
defer f.Close()
img_icon, _, _ := image.Decode(f)
// somewhere in window layout (added some context)
cell := g.Style().SetStyle(g.StyleVarItemSpacing, 4, 4).To(
g.ImageWithRgba(img_icon).Size(20, 20), // was working in giu v0.7
)
table_row := g.TreeTableRow("foobar", cell)
table := g.TreeTable().Rows(...) // etc
The example above crashes after a while when the TreeTable gets updated (some rows are added/removed). The stacktrace was the same as above - something about releasing/deleting the texture.
after:
var img_icon *image.RGBA
var tex_icon = &g.ReflectiveBoundTexture{}
// load image from file
f, _ := embed_fs.Open("icon.png")
defer f.Close()
img, _, _ := image.Decode(f)
img_icon = g.ImageToRgba(img)
// initialize texture
tex_icon.SetSurfaceFromRGBA(img_icon, false)
// somewhere in window layout (skipped context)
tex_icon.ToImageWidget().Size(20, 20)
The code above seems to work fine with the current master branch of giu (f64eda1) & cimgui-go (1a15ba4).
I have no idea if this issue should stay opened since I found the solution, but it took me some struggling to pinpoint the issue, and, I guess, it may break compatibility after upgrading from giu v0.7 to a newer version of giu/cimgui-go.
I'm also pretty new with Go, so it could be that I was doing (and maybe still doing) something wrong. If that's the case - would really appreciate the feedback!
@ioxenus we'll take a look at this since ImageWithRgba was thought to be (at last) fixed.
Aside from that, a quick advice: you do not need to do the image.Decode and g.ImageToRgba if you use g.ReflectiveBoundTexture as SetSurfaceFromFsFile takes a File object :)
- Taken from there: https://github.com/AllenDang/giu/blob/f64eda1a265477ed3079fbc07054346a70aaea75/examples/paint/toolbar.go#L43 you can change:
img, _, _ := image.Decode(f)
img_icon = g.ImageToRgba(img)
// initialize texture
tex_icon.SetSurfaceFromRGBA(img_icon, false)
to
err = tex_icon.SetSurfaceFromFsFile(f, false)
if err != nil {
return fmt.Errorf("error while Setting surface from File: %w", err)
}
You can take a look at SurfaceLoaders for more advanced cases that may be relevant:
- https://github.com/AllenDang/giu/blob/master/SurfaceLoaders.go#L166
