render

type Light struct {
	X, Y, Z float32  // Light position.
	Ld      data.Rgb // Light colour.
}

type M3 struct {
	X0, Y0, Z0 float32 // row 1 : indicies 0, 1, 2 [00, 01, 02]
	X1, Y1, Z1 float32 // row 2 : indicies 3, 4, 5 [10, 11, 12]
	X2, Y2, Z2 float32 // row 3 : indicies 6, 7, 8 [20, 21, 22]
}

type M4 struct {
	X0, Y0, Z0, W0 float32 // row 1 : indicies 0, 1, 2, 3 [00, 01, 02, 03]
	X1, Y1, Z1, W1 float32 // row 2 : indicies 4, 5, 6, 7 [10, 11, 12, 13]
	X2, Y2, Z2, W2 float32 // row 3 : indicies 8, 9, a, b [20, 21, 22, 23]
	X3, Y3, Z3, W3 float32 // row 4 : indicies c, d, e, f [30, 31, 32, 33]
}

type Renderer interface {
	Init() (err error)                    // Init must be called first and only once.
	Clear()                               // Clear all buffers before rendering.
	Color(r, g, b, a float32)             // Set the default render clear colour
	Enable(attribute uint32, enable bool) // Enable or disable graphic state.
	Viewport(width int, height int)       // Set the available screen real estate.
	MapTexture(tid int, t *data.Texture)  // Link textures with texture units.

	// BindModel makes mesh model data available to the graphics card.
	// This copies the model data into the graphics card memory.
	// Note that the model data is no longer needed in the CPU memory.
	BindModel(mesh *data.Mesh) (err error)

	// BindGlyphs makes bitmap font data available to the graphics card.
	BindGlyphs(mesh *data.Mesh) (err error)

	// BindTexture makes texture data available to the graphics card. This
	// copies the texture data into the graphics card memory. Note that the
	// texture data is no longer needed in the CPU memory.
	BindTexture(texture *data.Texture) (err error)

	// BindShader combines a vertex and fragment shader into a program.
	// Error information is returned when there are compile or link problems.
	BindShader(shader *data.Shader) (programRef uint32, err error)

	// Render draws 3D data. Render is expected to be called by a Mesh to render
	// itself. This will be called frequently as each Scene draws its parts
	// multiple times a second.
	Render(v *Vis)
}

type V3 struct {
	X, Y, Z float32
}

type Vis struct {
	Mv         *M4            // Model view.
	Mvp        *M4            // Model view projection.
	Scale      *V3            // Model scaling.
	L          *Light         // Light information.
	Alpha      float32        // Model alpha value.
	RotSpeed   float32        // Rotation speed.
	Fade       float32        // Fade value.
	Is2D       bool           // 2D or 3D.
	MeshName   string         // Mesh resource identifier.
	ShaderName string         // Shader identifier.
	MatName    string         // Material resource identifier.
	TexName    string         // Texture resource identifier.
	GlyphName  string         // Glyph resource identifier.
	GlyphText  string         // Banner text.
	GlyphPrev  string         // Previous banner text.
	GlyphWidth int            // Banner size.
	Mesh       *data.Mesh     // Mesh resource.
	Shader     *data.Shader   // Shader resource.
	Mat        *data.Material // Material resource.
	Tex        *data.Texture  // Texture resource.
	Glyph      *data.Glyphs   // Glyph resource.
}