Merge pull request #870 from cjbrigato/advanced-image-usage

Add advanced image usage tools with examples

ReflectiveBoundTexture.go

@@ -0,0 +1,258 @@
+package giu
+
+import (
+	"errors"
+	"hash/crc32"
+	"image"
+	"image/color"
+	"sync"
+
+	"github.com/AllenDang/cimgui-go/imgui"
+)
+
+// ErrNilRGBA is an error that indicates the RGBA surface result is nil.
+var ErrNilRGBA = errors.New("surface RGBA Result is nil")
+
+// defaultSurface returns a default RGBA surface with a uniform color.
+func defaultSurface() *image.RGBA {
+	surface, _ := NewUniformLoader(128.0, 128.0, color.RGBA{255, 255, 255, 255}).ServeRGBA()
+	return surface
+}
+
+// ReflectiveBoundTexture represents a texture that can be dynamically updated and bound to a GPU.
+type ReflectiveBoundTexture struct {
+	Surface *image.RGBA // Surface is the RGBA image data for the texture.
+	tex     *Texture    // tex is the GPU texture resource.
+	lastSum uint32      // lastSum is the checksum of the last surface data.
+	mu      sync.Mutex  // mu is a mutex to protect concurrent access to the texture.
+	fsroot  string      // fsroot is the root filesystem path for the texture when using file scheme in URL Surface Loader
+}
+
+/* Return a waranted:
+ * - Initialized
+ * - With proper resources bindings against gpu (free old, bound new)
+ * - Up to date Texture.
+ */
+
+// commit updates the ReflectiveBoundTexture by checking if the surface has changed,
+// and if so, rebinds the texture to the GPU. It returns the updated ReflectiveBoundTexture
+// and a boolean indicating whether the texture has changed.
+//
+// The method locks the texture for concurrent access, calculates the checksum of the
+// current surface, and compares it with the last stored checksum. If the checksums differ,
+// it unbinds the old texture, binds the new one, and updates the checksum.
+//
+// Returns:
+//   - *ReflectiveBoundTexture: The updated texture object.
+//   - bool: True if the texture has changed, false otherwise.
+func (i *ReflectiveBoundTexture) commit() (*ReflectiveBoundTexture, bool) {
+	i.mu.Lock()
+	defer i.mu.Unlock()
+
+	if i.Surface == nil {
+		i.Surface = defaultSurface()
+	}
+
+	var hasChanged bool
+	if sum := crc32.ChecksumIEEE(i.Surface.Pix); sum != i.lastSum {
+		hasChanged = true
+
+		i.unbind()
+		i.bind()
+		i.lastSum = sum
+	}
+
+	return i, hasChanged
+}
+
+// SetSurfaceFromRGBA sets the surface of the ReflectiveBoundTexture from the provided RGBA image.
+// If the provided image is nil, it returns an error. If the commit flag is true, it commits the changes.
+//
+// Parameters:
+//   - img: The RGBA image to set as the surface.
+//   - commit: A boolean flag indicating whether to commit the changes.
+//
+// Returns:
+//   - error: An error if the provided image is nil, otherwise nil.
+func (i *ReflectiveBoundTexture) SetSurfaceFromRGBA(img *image.RGBA, commit bool) error {
+	if img != nil {
+		i.Surface = img
+	} else {
+		return ErrNilRGBA
+	}
+
+	if commit {
+		i.commit()
+	}
+
+	return nil
+}
+
+// ToImageWidget converts the ReflectiveBoundTexture to an ImageWidget.
+//
+// Returns:
+//   - *ImageWidget: The ImageWidget representation of the ReflectiveBoundTexture.
+func (i *ReflectiveBoundTexture) ToImageWidget() *ImageWidget {
+	return Image(i.Texture())
+}
+
+// ImguiImageVOptionStruct represents the options for rendering an image in ImGui.
+type ImguiImageVOptionStruct struct {
+	Uv0       imgui.Vec2 // The UV coordinate of the top-left corner of the image.
+	Uv1       imgui.Vec2 // The UV coordinate of the bottom-right corner of the image.
+	TintCol   imgui.Vec4 // The tint color to apply to the image.
+	BorderCol imgui.Vec4 // The border color to apply to the image.
+}
+
+// GetImGuiImageVDefaultOptionsStruct returns the default options for rendering an image in ImGui.
+//
+// Returns:
+//   - ImguiImageVOptionStruct: The default options for rendering an image.
+func (i *ReflectiveBoundTexture) GetImGuiImageVDefaultOptionsStruct() ImguiImageVOptionStruct {
+	return ImguiImageVOptionStruct{
+		Uv0:       imgui.Vec2{X: 0, Y: 0},
+		Uv1:       imgui.Vec2{X: 1, Y: 1},
+		TintCol:   imgui.Vec4{X: 1, Y: 1, Z: 1, W: 1},
+		BorderCol: imgui.Vec4{X: 0, Y: 0, Z: 0, W: 0},
+	}
+}
+
+// ImguiImage renders the ReflectiveBoundTexture as an image in ImGui.
+//
+// Parameters:
+//   - width: The width of the image. If set to -1, it will use the available content region width.
+//   - height: The height of the image. If set to -1, it will use the available content region height.
+//   - options: The options for rendering the image.
+func (i *ReflectiveBoundTexture) ImguiImage(width, height float32) {
+	size := imgui.Vec2{X: width, Y: height}
+
+	if size.X == -1 {
+		rect := imgui.ContentRegionAvail()
+		size.X = rect.X
+	}
+
+	if size.Y == -1 {
+		rect := imgui.ContentRegionAvail()
+		size.Y = rect.Y
+	}
+
+	imgui.Image(i.Texture().ID(), size)
+}
+
+// ImguiImageV renders the ReflectiveBoundTexture as an image in ImGui with additional options.
+//
+// Parameters:
+//   - width: The width of the image. If set to -1, it will use the available content region width.
+//   - height: The height of the image. If set to -1, it will use the available content region height.
+//   - options: The options for rendering the image, including UV coordinates, tint color, and border color.
+func (i *ReflectiveBoundTexture) ImguiImageV(width, height float32, options ImguiImageVOptionStruct) {
+	size := imgui.Vec2{X: width, Y: height}
+
+	if size.X == -1 {
+		rect := imgui.ContentRegionAvail()
+		size.X = rect.X
+	}
+
+	if size.Y == -1 {
+		rect := imgui.ContentRegionAvail()
+		size.Y = rect.Y
+	}
+
+	imgui.ImageV(i.Texture().ID(), size, options.Uv0, options.Uv1, options.TintCol, options.BorderCol)
+}
+
+// ImguiImageButtonV renders the ReflectiveBoundTexture as an image button in ImGui with additional options.
+//
+// Parameters:
+//   - id: The ID of the image button.
+//   - width: The width of the image button. If set to -1, it will use the available content region width.
+//   - height: The height of the image button. If set to -1, it will use the available content region height.
+//   - options: The options for rendering the image button, including UV coordinates, tint color, and border color.
+func (i *ReflectiveBoundTexture) ImguiImageButtonV(id string, width, height float32, options ImguiImageVOptionStruct) {
+	size := imgui.Vec2{X: width, Y: height}
+
+	if size.X == -1 {
+		rect := imgui.ContentRegionAvail()
+		size.X = rect.X
+	}
+
+	if size.Y == -1 {
+		rect := imgui.ContentRegionAvail()
+		size.Y = rect.Y
+	}
+
+	imgui.ImageButtonV(id, i.Texture().ID(), size, options.Uv0, options.Uv1, options.TintCol, options.BorderCol)
+}
+
+// unbind releases the texture associated with the ReflectiveBoundTexture from the backend.
+func (i *ReflectiveBoundTexture) unbind() {
+	if i.tex != nil {
+		Context.Backend().DeleteTexture(i.tex.ID())
+		i.tex = nil
+	}
+}
+
+// bind creates a new texture from the RGBA surface and assigns it to the ReflectiveBoundTexture.
+func (i *ReflectiveBoundTexture) bind() {
+	NewTextureFromRgba(i.Surface, func(tex *Texture) {
+		i.tex = tex
+	})
+}
+
+// GetSurfaceWidth returns the width of the RGBA surface.
+func (i *ReflectiveBoundTexture) GetSurfaceWidth() int {
+	return i.Surface.Bounds().Dx()
+}
+
+// GetSurfaceHeight returns the height of the RGBA surface.
+func (i *ReflectiveBoundTexture) GetSurfaceHeight() int {
+	return i.Surface.Bounds().Dy()
+}
+
+// GetSurfaceSize returns the size of the RGBA surface as an image.Point.
+func (i *ReflectiveBoundTexture) GetSurfaceSize() image.Point {
+	return i.Surface.Bounds().Size()
+}
+
+// Texture commits any pending changes to the RGBA surface and returns the associated texture.
+func (i *ReflectiveBoundTexture) Texture() *Texture {
+	i.commit()
+	return i.tex
+}
+
+// TextureID commits any pending changes and returns the ImGui TextureID of the associated texture.
+func (i *ReflectiveBoundTexture) TextureID() imgui.TextureID {
+	return i.Texture().ID()
+}
+
+// GetRGBA returns the RGBA surface of the ReflectiveBoundTexture.
+// If the commit parameter is true, it commits any pending changes before returning the surface.
+//
+// Parameters:
+//   - commit: A boolean indicating whether to commit any pending changes.
+//
+// Returns:
+//   - *image.RGBA: The RGBA surface of the ReflectiveBoundTexture.
+func (i *ReflectiveBoundTexture) GetRGBA(commit bool) *image.RGBA {
+	if commit {
+		i.commit()
+	}
+
+	return i.Surface
+}
+
+// ForceRelease forces releasing resources against all finalizers,
+// effectively losing the object but ensuring both RAM and VRAM
+// are freed.
+func (i *ReflectiveBoundTexture) ForceRelease() {
+	i.unbind()
+	i.Surface = nil
+
+	var u uint32
+	i.lastSum = u
+}
+
+// ForceCommit forces committing.
+func (i *ReflectiveBoundTexture) ForceCommit() (*ReflectiveBoundTexture, bool) {
+	return i.commit()
+}