examples: add gizmo usage example

examples/common/common.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/AllenDang/cimgui-go/backend"
 	"github.com/AllenDang/cimgui-go/imgui"
+	"github.com/AllenDang/cimgui-go/imguizmo"
 	_ "github.com/AllenDang/cimgui-go/imguizmo"
 	_ "github.com/AllenDang/cimgui-go/immarkdown"
 	_ "github.com/AllenDang/cimgui-go/imnodes"
@@ -60,9 +61,11 @@ func BeforeDestroyContext() {
 }
 
 func Loop() {
+	imguizmo.BeginFrame()
 	ShowWidgetsDemo()
 	ShowPictureLoadingDemo()
 	ShowImPlotDemo()
+	ShowGizmoDemo()
 }
 
 func ShowWidgetsDemo() {

examples/common/gizmo.go

@@ -0,0 +1,171 @@
+// Example of using imguizmo.
+package common
+
+import (
+	"github.com/AllenDang/cimgui-go/imgui"
+	"github.com/AllenDang/cimgui-go/imguizmo"
+)
+
+var (
+	// here are some 4x4 matries. Generally IDK what are they doing - figure it yourself :-)
+	// Well, This one is parsed in an editor below.
+	View = []float32{
+		1, 0, 0, 0,
+		0, 1, 0, 0,
+		0, 0, 1, 0,
+		0, 0, -7, 1,
+	}
+
+	Projection = []float32{
+		2.3787, 0, 0, 0,
+		0, 3.1716, 0, 0,
+		0, 0, -1.0002, -1,
+		0, 0, -0.2, 0,
+	}
+
+	Ident = []float32{
+		1, 0, 0, 0,
+		0, 1, 0, 0,
+		0, 0, 1, 0,
+		0, 0, 0, 1,
+	}
+
+	MOmo = []float32{
+		1, 0, 0, 0,
+		0, 1, 0, 0,
+		0, 0, 1, 0,
+		0.5, 0.5, 0.5, 1,
+	}
+
+	zmoOP   = int32(imguizmo.TRANSLATE)
+	zmoMODE = int32(imguizmo.LOCAL)
+
+	Bounds = []float32{-0.5, -0.5, -0.5, 0.5, 0.5, 0.5}
+
+	// GizmoControls can be enabled in editor and allows mouse control over gizmo
+	GizmoControls bool
+	UsingGizmo    bool
+)
+
+func ShowGizmoDemo() {
+	basePos := imgui.MainViewport().Pos()
+	imgui.SetNextWindowPosV(imgui.NewVec2(basePos.X+400, basePos.Y+460), imgui.CondOnce, imgui.NewVec2(0, 0))
+	if imgui.Begin("Gizmo editor") {
+		imgui.Checkbox("Enable controls", &GizmoControls)
+		imgui.RadioButtonIntPtr("trans", &zmoOP, int32(imguizmo.TRANSLATE))
+		imgui.SameLine()
+		imgui.RadioButtonIntPtr("rot", &zmoOP, int32(imguizmo.ROTATE))
+		imgui.SameLine()
+		imgui.RadioButtonIntPtr("scale", &zmoOP, int32(imguizmo.SCALE))
+		imgui.SameLine()
+		imgui.RadioButtonIntPtr("bounds", &zmoOP, int32(imguizmo.BOUNDS))
+		imgui.RadioButtonIntPtr("local", &zmoMODE, int32(imguizmo.LOCAL))
+		imgui.SameLine()
+		imgui.RadioButtonIntPtr("world", &zmoMODE, int32(imguizmo.WORLD))
+
+		imgui.Separator()
+		imgui.Text("View:")
+		// float matrixTranslation[3], matrixRotation[3], matrixScale[3];
+		// ImGuizmo::DecomposeMatrixToComponents(gizmoMatrix.m16, matrixTranslation, matrixRotation, matrixScale);
+		// ImGui::InputFloat3("Tr", matrixTranslation, 3);
+		// ImGui::InputFloat3("Rt", matrixRotation, 3);
+		// ImGui::InputFloat3("Sc", matrixScale, 3);
+		// ImGuizmo::RecomposeMatrixFromComponents(matrixTranslation, matrixRotation, matrixScale, gizmoMatrix.m16);
+		matrixTranslation, matrixRotation, matrixScale := make([]float32, 3), make([]float32, 3), make([]float32, 3)
+		imguizmo.DecomposeMatrixToComponents(
+			&(View[0]),
+			&(matrixTranslation[0]),
+			&(matrixRotation[0]),
+			&(matrixScale[0]),
+		)
+
+		imgui.PushItemWidth(80)
+		imgui.DragFloatV("TrX", &matrixTranslation[0], .1, 0.0, 0.0, "%.3f", 0)
+		imgui.SameLine()
+		imgui.DragFloatV("TrY", &matrixTranslation[1], .1, 0.0, 0.0, "%.3f", 0)
+		imgui.SameLine()
+		imgui.DragFloatV("TrZ", &matrixTranslation[2], .1, 0.0, 0.0, "%.3f", 0)
+		imgui.PopItemWidth()
+
+		imgui.Separator()
+		imgui.Text("Projection:")
+		imgui.PushItemWidth(80)
+		imgui.DragFloatV("PrX", &matrixRotation[0], .1, 0.0, 0.0, "%.3f", 0)
+		imgui.SameLine()
+		imgui.DragFloatV("PrY", &matrixRotation[1], .1, 0.0, 0.0, "%.3f", 0)
+		imgui.SameLine()
+		imgui.DragFloatV("PrZ", &matrixRotation[2], .1, 0.0, 0.0, "%.3f", 0)
+		imgui.PopItemWidth()
+
+		imgui.Separator()
+		imgui.Text("Scale:")
+		imgui.PushItemWidth(80)
+		imgui.DragFloatV("ScX", &matrixScale[0], .1, 0.0, 0.0, "%.3f", 0)
+		imgui.SameLine()
+		imgui.DragFloatV("ScY", &matrixScale[1], .1, 0.0, 0.0, "%.3f", 0)
+		imgui.SameLine()
+		imgui.DragFloatV("ScZ", &matrixScale[2], .1, 0.0, 0.0, "%.3f", 0)
+		imgui.PopItemWidth()
+
+		if GizmoControls && !imgui.IsWindowFocused() && !UsingGizmo {
+			io := imgui.CurrentIO()
+			matrixTranslation[2] += io.MouseWheel()
+			if leftMouseButton := io.MouseDown()[0]; leftMouseButton {
+				const scale = 0.01
+				d := io.MouseDelta()
+				matrixTranslation[0] += d.X * scale
+				matrixTranslation[1] -= d.Y * scale
+			}
+			if rightMouseButton := io.MouseDown()[1]; rightMouseButton {
+				const scale = 0.1
+				d := io.MouseDelta()
+				matrixRotation[1] += d.X * scale
+				/*
+					matrixRotation[0] = Clamp(matrixRotation[0]+d.Y*scale*(1-matrixRotation[1]/90), 0, 90)
+					matrixRotation[2] = Clamp(matrixRotation[2]+d.Y*scale*matrixRotation[1]/90, 0, 90)
+				*/
+			}
+		}
+
+		imguizmo.RecomposeMatrixFromComponents(
+			&(matrixTranslation[0]),
+			&(matrixRotation[0]),
+			&(matrixScale[0]),
+			&(View[0]),
+		)
+	}
+	imgui.End()
+
+	gio := imgui.CurrentIO()
+	imguizmo.SetRect(0, 0, gio.DisplaySize().X, gio.DisplaySize().Y)
+	imguizmo.SetOrthographic(false)
+	imguizmo.DrawGrid(
+		&(View[0]),
+		&(Projection[0]),
+		&(Ident[0]),
+		10)
+
+	imguizmo.DrawCubes(
+		&(View[0]),
+		&(Projection[0]),
+		&(MOmo[0]),
+		1)
+
+	imguizmo.ManipulateV(
+		&(View[0]), &(Projection[0]),
+		imguizmo.OPERATION(zmoOP),
+		imguizmo.MODE(zmoMODE),
+		&(MOmo[0]),
+		nil, nil,
+		func() *float32 {
+			if imguizmo.OPERATION(zmoOP) == imguizmo.BOUNDS {
+				return &(Bounds[0])
+			}
+
+			return nil
+		}(),
+		nil)
+
+	imguizmo.ViewManipulateFloat(&(View[0]), 7, imgui.Vec2{0, 0}, imgui.Vec2{128, 128}, 0x01010101)
+	UsingGizmo = imguizmo.IsUsingAny()
+}