We are nearly done there. Fix Onclick widget with Size consideration,…

… Add Scale operation in imageWidget, implement SurfaceLoaders for easy extension of loading images, change loading image example for advanced drawings and controls, updates URL downloaded images. Last Step: URL With OnError/OnLoading to mimic old behavior with better extension. Linting, Documentation.

ImageWidgets.go

@@ -24,6 +24,7 @@ type ImageWidget struct {
 	texture                *Texture
 	width                  float32
 	height                 float32
+	scale                  imgui.Vec2
 	uv0, uv1               imgui.Vec2
 	tintColor, borderColor color.Color
 	onClick                func()
@@ -35,6 +36,7 @@ func Image(texture *Texture) *ImageWidget {
 		texture:     texture,
 		width:       0,
 		height:      0,
+		scale:       imgui.Vec2{X: 1, Y: 1},
 		uv0:         imgui.Vec2{X: 0, Y: 0},
 		uv1:         imgui.Vec2{X: 1, Y: 1},
 		tintColor:   color.RGBA{255, 255, 255, 255},
@@ -74,6 +76,13 @@ func (i *ImageWidget) Size(width, height float32) *ImageWidget {
 	return i
 }
 
+// Scale multiply dimensions after size
+func (i *ImageWidget) Scale(scaleX, ScaleY float32) *ImageWidget {
+	// Size image with DPI scaling
+	i.scale = imgui.Vec2{scaleX, ScaleY}
+	return i
+}
+
 // Build implements Widget interface.
 func (i *ImageWidget) Build() {
 	if i.width == 0 && i.height == 0 {
@@ -96,6 +105,9 @@ func (i *ImageWidget) Build() {
 		size.Y = rect.Y
 	}
 
+	size.X = size.X * i.scale.X
+	size.Y = size.Y * i.scale.Y
+
 	if i.texture == nil || i.texture.tex == nil {
 		Dummy(size.X, size.Y).Build()
 		return
@@ -107,7 +119,7 @@ func (i *ImageWidget) Build() {
 		mousePos := GetMousePos()
 
 		if cursorPos.X <= mousePos.X && cursorPos.Y <= mousePos.Y &&
-			cursorPos.X+int(i.width) >= mousePos.X && cursorPos.Y+int(i.height) >= mousePos.Y {
+			cursorPos.X+int(size.X) >= mousePos.X && cursorPos.Y+int(size.Y) >= mousePos.Y {
 			i.onClick()
 		}
 	}

ReflectiveBoundTexture.go

@@ -10,20 +10,19 @@ import (
 	imgui "github.com/AllenDang/cimgui-go"
 )
 
-func defaultCanvas() *image.RGBA {
-	white := color.RGBA{255, 255, 255, 255}
-	return newImage(800, 600, white)
+func defaultSurface() *image.RGBA {
+	surface, _ := UniformLoader(REFLECTIVE_SURFACE_DEFAULT_WIDTH, REFLECTIVE_SURFACE_DEFAULT_HEIGHT, REFLECTIVE_SURFACE_DEFAULT_COLOR).ServeRGBA()
+	return surface
 }
 
-func newImage(width, height int, bgColor color.Color) *image.RGBA {
-	img := image.NewRGBA(image.Rect(0, 0, width, height))
-	for y := 0; y < height; y++ {
-		for x := 0; x < width; x++ {
-			img.Set(x, y, bgColor)
-		}
-	}
-	return img
-}
+const (
+	REFLECTIVE_SURFACE_DEFAULT_WIDTH  = 128
+	REFLECTIVE_SURFACE_DEFAULT_HEIGHT = 128
+)
+
+var (
+	REFLECTIVE_SURFACE_DEFAULT_COLOR = color.RGBA{255, 255, 255, 255}
+)
 
 type ReflectiveBoundTexture struct {
 	Surface *image.RGBA
@@ -41,7 +40,7 @@ func (i *ReflectiveBoundTexture) commit() (*ReflectiveBoundTexture, bool) {
 	i.mu.Lock()
 	defer i.mu.Unlock()
 	if i.Surface == nil {
-		i.Surface = defaultCanvas()
+		i.Surface = defaultSurface()
 	}
 
 	var has_changed bool
@@ -54,24 +53,6 @@ func (i *ReflectiveBoundTexture) commit() (*ReflectiveBoundTexture, bool) {
 	return i, has_changed
 }
 
-func (i *ReflectiveBoundTexture) SetSurfaceFn(fn func() *image.RGBA, commit bool) error {
-	img := fn()
-	return i.SetSurfaceFromRGBA(img, commit)
-}
-
-func (i *ReflectiveBoundTexture) SetSurfaceFromFillRect(width int, height int, c color.Color, commit bool) error {
-	img := newImage(width, height, c)
-	return i.SetSurfaceFromRGBA(img, commit)
-}
-
-func (i *ReflectiveBoundTexture) SetSurfaceFromFile(path string, commit bool) error {
-	img, err := LoadImage(path)
-	if err != nil {
-		return err
-	}
-	return i.SetSurfaceFromRGBA(img, commit)
-}
-
 func (i *ReflectiveBoundTexture) SetSurfaceFromRGBA(img *image.RGBA, commit bool) error {
 	if img != nil {
 		i.Surface = img
@@ -164,6 +145,18 @@ func (i *ReflectiveBoundTexture) bind() {
 	})
 }
 
+func (i *ReflectiveBoundTexture) GetSurfaceWidth() int {
+	return i.Surface.Bounds().Dx()
+}
+
+func (i *ReflectiveBoundTexture) GetSurfaceHeight() int {
+	return i.Surface.Bounds().Dy()
+}
+
+func (i *ReflectiveBoundTexture) GetSurfaceSize() image.Point {
+	return i.Surface.Bounds().Size()
+}
+
 func (i *ReflectiveBoundTexture) Texture() *Texture {
 	i.commit()
 	return i.tex

SurfaceLoaders.go

@@ -0,0 +1,124 @@
+package giu
+
+import (
+	go_ctx "context"
+	"image"
+	"image/color"
+	"image/draw"
+	"net/http"
+	"time"
+)
+
+// SurfaceLoader interface
+type SurfaceLoader interface {
+	ServeRGBA() (*image.RGBA, error)
+}
+type SurfaceLoaderFunc func() (*image.RGBA, error)
+
+func (i *ReflectiveBoundTexture) LoadSurfaceFunc(fn SurfaceLoaderFunc, commit bool) error {
+	img, err := fn()
+	if err != nil {
+		return err
+	}
+	return i.SetSurfaceFromRGBA(img, commit)
+}
+
+func (i *ReflectiveBoundTexture) LoadSurface(loader SurfaceLoader, commit bool) error {
+	img, err := loader.ServeRGBA()
+	if err != nil {
+		return err
+	}
+	return i.SetSurfaceFromRGBA(img, commit)
+}
+
+// FileLoader
+
+type fileLoader struct {
+	path string
+}
+
+func (f *fileLoader) ServeRGBA() (*image.RGBA, error) {
+	img, err := LoadImage(f.path)
+	if err != nil {
+		return nil, err
+	}
+	return img, nil
+}
+
+func FileLoader(path string) SurfaceLoader {
+	return &fileLoader{
+		path: path,
+	}
+}
+
+func (i *ReflectiveBoundTexture) SetSurfaceFromFile(path string, commit bool) error {
+	return i.LoadSurface(FileLoader(path), commit)
+}
+
+// UrlLoader
+
+type urlLoader struct {
+	url     string
+	timeout time.Duration
+}
+
+func (u *urlLoader) ServeRGBA() (*image.RGBA, error) {
+	client := &http.Client{Timeout: u.timeout}
+	req, err := http.NewRequestWithContext(go_ctx.Background(), "GET", u.url, http.NoBody)
+	if err != nil {
+		//errorFn(err)
+		return nil, err
+	}
+	resp, err := client.Do(req)
+	if err != nil {
+		//errorFn(err)
+		return nil, err
+	}
+	defer resp.Body.Close()
+	/*defer func() {
+		if closeErr := resp.Body.Close(); closeErr != nil {
+			errorFn(closeErr)
+		}
+	}()*/
+	img, _, err := image.Decode(resp.Body)
+	if err != nil {
+		//errorFn(err)
+		return nil, err
+	}
+	return ImageToRgba(img), nil
+}
+
+func URLLoader(url string, timeout time.Duration) SurfaceLoader {
+	return &urlLoader{
+		url:     url,
+		timeout: timeout,
+	}
+}
+
+func (i *ReflectiveBoundTexture) SetSurfaceFromURL(url string, timeout time.Duration, commit bool) error {
+	return i.LoadSurface(URLLoader(url, timeout), commit)
+}
+
+// UniformLoader
+type uniformLoader struct {
+	width, height int
+	color         color.Color
+}
+
+func (u *uniformLoader) ServeRGBA() (*image.RGBA, error) {
+	img := image.NewRGBA(image.Rect(0, 0, u.width, u.height))
+	draw.Draw(img, img.Bounds(), &image.Uniform{u.color}, image.ZP, draw.Src)
+	return img, nil
+}
+
+func UniformLoader(width, height int, color color.Color) SurfaceLoader {
+	return &uniformLoader{
+		width:  width,
+		height: height,
+		color:  color,
+	}
+}
+
+func (i *ReflectiveBoundTexture) SetSurfaceUniform(width int, height int, c color.Color, commit bool) error {
+	return i.LoadSurface(UniformLoader(width, height, c), commit)
+}

examples/loadimage/loadimage.go

@@ -1,45 +1,70 @@
 package main
 
 import (
-	"context"
 	"fmt"
 	"image"
 	_ "image/jpeg"
 	_ "image/png"
 	"log"
-	"net/http"
 	"time"
 
+	imgui "github.com/AllenDang/cimgui-go"
 	g "github.com/AllenDang/giu"
 )
 
 var (
-	fallback      = &g.ReflectiveBoundTexture{}
-	gopher        = &g.ReflectiveBoundTexture{}
-	urlWidgetLike = &g.ReflectiveBoundTexture{}
-	rgba          *image.RGBA
+	fromrgba     = &g.ReflectiveBoundTexture{}
+	fromfile     = &g.ReflectiveBoundTexture{}
+	fromurl      = &g.ReflectiveBoundTexture{}
+	rgba         *image.RGBA
+	sonicOffsetX = int32(1180)
+	sonicOffsetY = int32(580)
 )
 
 func loop() {
-
-	urlWidgetLike.SetSurfaceFn(downloadUrlFn("https://static.wikia.nocookie.net/smashbros/images/0/0e/Art_Sonic_TSR.png/revision/latest?cb=20200210122913&path-prefix=fr", time.Second*10), true)
+	var start_pos image.Point
+	var window_size imgui.Vec2
 	g.SingleWindow().Layout(
-		g.Label("Display image from texture"),
-		gopher.ToImageWidget(),
-		g.Label("Display image from fallback"),
-		fallback.ToImageWidget().OnClick(func() {
+		g.Custom(func() {
+			start_pos = g.GetCursorScreenPos()
+			window_size = imgui.WindowSize()
+		}),
+		g.Label("Display wich has size of contentAvaiable (stretch)"),
+		fromfile.ToImageWidget().OnClick(func() {
+			fmt.Println("contentAvailable image was clicked")
+		}).Size(-1, -1),
+
+		g.Label("Display image from preloaded rgba"),
+		fromrgba.ToImageWidget().OnClick(func() {
 			fmt.Println("rgba image was clicked")
-		}).Size(600, 400),
-		g.Label("Display image from gopher"),
-		gopher.ToImageWidget().OnClick(func() {
+		}),
+
+		g.Label("Display image from file"),
+		fromfile.ToImageWidget().OnClick(func() {
 			fmt.Println("image from file was clicked")
-		}).Size(860, 561),
+		}),
 
-		// TODO Rewrite via func (i *ReflectiveBoundTexture) SetSurfaceFn(fn func() *image.RGBA, commit bool) error {
-		g.Label("Display image from url (wait few seconds to download)"),
-		g.ImageWithURL("https://png.pngitem.com/pimgs/s/3-36108_gopher-golang-hd-png-download.png").OnClick(func() {
+		g.Label("Display image from url + 0.25 scale"),
+		fromurl.ToImageWidget().OnClick(func() {
 			fmt.Println("image from url clicked")
-		}).Size(300, 200),
+		}).Scale(0.25, 0.25),
+
+		g.Label("Advanced Drawing manipulation"),
+		g.DragInt("Sonic Offset X", &sonicOffsetX, 0, 1280),
+		g.DragInt("Sonic Offset Y", &sonicOffsetY, 0, 720),
+		g.Custom(func() {
+			size := fromurl.GetSurfaceSize()
+			sonicOffset := image.Point{int(sonicOffsetX), int(sonicOffsetY)}
+			pos_with_offset := start_pos.Add(sonicOffset)
+			computed_posX := (float32(pos_with_offset.X)) + imgui.ScrollX()
+			computed_posY := (float32(pos_with_offset.Y)) + imgui.ScrollY()
+			//cur_pos := g.GetCursorPos()
+			scale := imgui.Vec2{0.10, 0.10}
+			p_min := imgui.Vec2{computed_posX, computed_posY}
+			p_max := imgui.Vec2{computed_posX + float32(size.X)*scale.X, computed_posY + float32(size.Y)*scale.Y}
+			imgui.ForegroundDrawList().AddImage(fromurl.Texture().ID(), p_min, p_max)
+		}),
+
 		/*
 			g.Label("Display images from url with loading and fallback"),
 			g.Label("Display image from url without placeholder (no size when loading)"),
@@ -76,39 +101,10 @@ func main() {
 	if err != nil {
 		log.Fatalf("Cannot loadIamge fallback.png")
 	}
-	gopher.SetSurfaceFromFile("gopher.png", false)
-	fallback.SetSurfaceFromRGBA(rgba, false)
+	fromfile.SetSurfaceFromFile("gopher.png", false)
+	fromrgba.SetSurfaceFromRGBA(rgba, false)
+	fromurl.SetSurfaceFromURL("https://static.wikia.nocookie.net/smashbros/images/0/0e/Art_Sonic_TSR.png/revision/latest?cb=20200210122913&path-prefix=fr", time.Second*5, false)
 
-	wnd := g.NewMasterWindow("Load Image", 600, 500, g.MasterWindowFlagsNotResizable)
-	//wnd.SetIcon(rgba)
+	wnd := g.NewMasterWindow("Load Image", 1280, 720, 0)
 	wnd.Run(loop)
 }
-
-func downloadUrlFn(imgUrl string, timeout time.Duration) func() *image.RGBA {
-	return func() *image.RGBA {
-		client := &http.Client{Timeout: timeout}
-		req, err := http.NewRequestWithContext(context.Background(), "GET", imgUrl, http.NoBody)
-		if err != nil {
-			//errorFn(err)
-			return nil
-		}
-		resp, err := client.Do(req)
-		if err != nil {
-			//errorFn(err)
-			return nil
-		}
-		defer resp.Body.Close()
-		/*defer func() {
-			if closeErr := resp.Body.Close(); closeErr != nil {
-				errorFn(closeErr)
-			}
-		}()*/
-		img, _, err := image.Decode(resp.Body)
-		if err != nil {
-			//errorFn(err)
-			return nil
-		}
-		return g.ImageToRgba(img)
-
-	}
-}

go.mod

@@ -24,3 +24,5 @@ require (
 	golang.org/x/sys v0.5.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
+
+