Initial commit

internal/render/render_framewire.go

@@ -0,0 +1,127 @@
+package render
+
+import (
+	"image/color"
+	"unsafe"
+
+	"edgaru089.ml/go/gl01/internal/asset"
+	"edgaru089.ml/go/gl01/internal/util/itype"
+	"github.com/go-gl/gl/all-core/gl"
+	"github.com/go-gl/mathgl/mgl32"
+)
+
+// framewire vertex
+type frvertex struct {
+	pos   itype.Vec3f
+	color itype.Vec4f
+}
+
+// FramewireRenderer is a renderer drawing framewires.
+//
+// It is mainly for debugging uses.
+type FramewireRenderer struct {
+	shader *Shader
+
+	vao, vbo uint32
+	vertex   []frvertex
+}
+
+// Framewire is a global FramewireRenderer managed by game logic, for debugging.
+var Framewire = &FramewireRenderer{}
+
+func (f *FramewireRenderer) Init() (err error) {
+
+	f.shader, err = NewShader(asset.FramewireShaderVert, asset.FramewireShaderFrag)
+	if err != nil {
+		return err
+	}
+
+	f.shader.SetUniformMat4("model", mgl32.Ident4())
+	gl.BindFragDataLocation(f.shader.Handle(), 0, gl.Str("outputColor\x00"))
+
+	gl.GenVertexArrays(1, &f.vao)
+	gl.BindVertexArray(f.vao)
+	gl.GenBuffers(1, &f.vbo)
+	gl.BindBuffer(gl.ARRAY_BUFFER, f.vbo)
+
+	vertAttrib := uint32(gl.GetAttribLocation(f.shader.Handle(), gl.Str("vert\x00")))
+	gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, int32(unsafe.Sizeof(frvertex{})), gl.PtrOffset(int(unsafe.Offsetof(frvertex{}.pos))))
+
+	colorAttrib := uint32(gl.GetAttribLocation(f.shader.Handle(), gl.Str("vertColor\x00")))
+	gl.VertexAttribPointer(colorAttrib, 4, gl.FLOAT, false, int32(unsafe.Sizeof(frvertex{})), gl.PtrOffset(int(unsafe.Offsetof(frvertex{}.color))))
+
+	gl.EnableVertexAttribArray(vertAttrib)
+	gl.EnableVertexAttribArray(colorAttrib)
+
+	return nil
+}
+
+func colorToVec4f(color color.Color) itype.Vec4f {
+	r, g, b, a := color.RGBA()
+	return itype.Vec4f{float32(r) / 0xffff, float32(g) / 0xffff, float32(b) / 0xffff, float32(a) / 0xffff}
+}
+
+// PushLine pushes a line from p0 to p1 into the vertex array.
+func (f *FramewireRenderer) PushLine(p0, p1 itype.Vec3f, color0, color1 color.Color) {
+	f.vertex = append(f.vertex,
+		frvertex{
+			pos:   p0,
+			color: colorToVec4f(color0),
+		},
+		frvertex{
+			pos:   p1,
+			color: colorToVec4f(color1),
+		},
+	)
+}
+
+const FramewireSizeShrink = 1e-2
+
+// PushBox pushes a 3D box into the vertex array.
+//
+// The size of the box is shrunk by a little bit so that it is not obstructed by the world.
+func (f *FramewireRenderer) PushBox(box itype.Boxf, color color.Color) {
+	box = itype.Boxf{
+		OffX:  box.OffX + FramewireSizeShrink,
+		OffY:  box.OffY + 5*FramewireSizeShrink,
+		OffZ:  box.OffZ + FramewireSizeShrink,
+		SizeX: box.SizeX - 2*FramewireSizeShrink,
+		SizeY: box.SizeY - 10*FramewireSizeShrink,
+		SizeZ: box.SizeZ - 2*FramewireSizeShrink,
+	}
+	base := box.MinPoint()
+
+	f.PushLine(base, base.Addv(box.SizeX, 0, 0), color, color)
+	f.PushLine(base, base.Addv(0, 0, box.SizeZ), color, color)
+	f.PushLine(base.Addv(box.SizeX, 0, box.SizeZ), base.Addv(box.SizeX, 0, 0), color, color)
+	f.PushLine(base.Addv(box.SizeX, 0, box.SizeZ), base.Addv(0, 0, box.SizeZ), color, color)
+
+	f.PushLine(base, base.Addv(0, box.SizeY, 0), color, color)
+	f.PushLine(base.Addv(box.SizeX, 0, 0), base.Addv(box.SizeX, box.SizeY, 0), color, color)
+	f.PushLine(base.Addv(0, 0, box.SizeZ), base.Addv(0, box.SizeY, box.SizeZ), color, color)
+	f.PushLine(base.Addv(box.SizeX, 0, box.SizeZ), base.Addv(box.SizeX, box.SizeY, box.SizeZ), color, color)
+
+	f.PushLine(base.Addv(0, box.SizeY, 0), base.Addv(box.SizeX, box.SizeY, 0), color, color)
+	f.PushLine(base.Addv(0, box.SizeY, 0), base.Addv(0, box.SizeY, box.SizeZ), color, color)
+	f.PushLine(base.Addv(box.SizeX, box.SizeY, box.SizeZ), base.Addv(box.SizeX, box.SizeY, 0), color, color)
+	f.PushLine(base.Addv(box.SizeX, box.SizeY, box.SizeZ), base.Addv(0, box.SizeY, box.SizeZ), color, color)
+}
+
+// Render renders the framewire into the current OpenGL context and clears it.
+func (f *FramewireRenderer) Render(view *View) {
+	if len(f.vertex) == 0 {
+		return
+	}
+
+	f.shader.UseProgram()
+	f.shader.SetUniformMat4("view", view.View())
+	f.shader.SetUniformMat4("projection", view.Perspective())
+
+	gl.BindVertexArray(f.vao)
+	gl.BindBuffer(gl.ARRAY_BUFFER, f.vbo)
+	gl.BufferData(gl.ARRAY_BUFFER, len(f.vertex)*int(unsafe.Sizeof(frvertex{})), gl.Ptr(f.vertex), gl.STREAM_DRAW)
+
+	gl.DrawArrays(gl.LINES, 0, int32(len(f.vertex)))
+
+	f.vertex = f.vertex[0:0]
+}