package render

import (
	"github.com/pnx/go-raytracer/graphics"
	"github.com/pnx/go-raytracer/math"
	"github.com/pnx/go-raytracer/world"
)

func DrawColumn(ctx *graphics.Context, x int32, wall_h int32, color byte) {
	if wall_h < ctx.Height() {
		y1 := (ctx.Height() - wall_h) / 2
		y2 := (ctx.Height() + wall_h) / 2

		// Top
		// renderer.SetDrawColor(90, 90, 0, 255)
		ctx.DrawLine(x, 0, int32(x), y1, 0x1D)

		// // Middle
		// renderer.SetDrawColor(color.R, color.G, color.B, color.A)
		ctx.DrawLine(x, y1, int32(x), y2, color)

		// Bottom
		if y2 < ctx.Height() {
			// renderer.SetDrawColor(50, 50, 50, 255)
			ctx.DrawLine(x, y2, int32(x), ctx.Height(), 0x19)
		}
		return
	}

	// ctx.SetDrawColor(color.R, color.G, color.B, color.A)
	ctx.DrawLine(x, 0, int32(x), ctx.Height(), color)
}

func DrawScene(ctx *graphics.Context, camera math.Transform, level *world.Level) {
	for x := range ctx.Width() {
		result := CastRay(camera, level, int(x), int(ctx.Width()))
		lineHeight := int(float64(ctx.Height()) / result.Distance)

		color := level.Cell(int(result.Cell.X), int(result.Cell.Y))

		if result.Side > 0 {
			color += 0x8
		}

		DrawColumn(ctx, int32(x), int32(lineHeight), color)
	}
}