/*******************************************************************************************
*
*   raylib [models] example - Draw textured cube
*
*   Example originally created with raylib 4.5, last time updated with raylib 4.5
*
*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
*   BSD-like license that allows static linking with closed source software
*
*   Copyright (c) 2022-2024 Ramon Santamaria (@raysan5)
*
********************************************************************************************/
package main

import rl "github.com/gen2brain/raylib-go/raylib"

const (
	screenWidth  = 800
	screenHeight = 450
)

func main() {
	rl.InitWindow(screenWidth, screenHeight, "raylib [models] example - draw cube texture")

	// Define the camera to look into our 3d world
	camera := rl.Camera{
		Position: rl.Vector3{
			Y: 10.0,
			Z: 10.0,
		},
		Target:     rl.Vector3{},
		Up:         rl.Vector3{Y: 1.0},
		Fovy:       45.0,
		Projection: rl.CameraPerspective,
	}

	// Load texture to be applied to the cubes sides
	texture := rl.LoadTexture("cubicmap_atlas.png")

	rl.SetTargetFPS(60) // Set our game to run at 60 frames-per-second

	// Main game loop
	for !rl.WindowShouldClose() { // Detect window close button or ESC key
		// Update
		// TODO: Update your variables here

		// Draw
		rl.BeginDrawing()
		rl.ClearBackground(rl.RayWhite)
		rl.BeginMode3D(camera)

		// Draw cube with an applied texture
		vec := rl.Vector3{
			X: -2.0,
			Y: 2.0,
		}
		DrawCubeTexture(texture, vec, 2.0, 4.0, 2.0, rl.White)

		// Draw cube with an applied texture, but only a defined rectangle piece of the texture
		rec := rl.Rectangle{
			Y:      float32(texture.Height) / 2.0,
			Width:  float32(texture.Width) / 2.0,
			Height: float32(texture.Height) / 2.0,
		}
		vec = rl.Vector3{
			X: 2.0,
			Y: 1.0,
		}
		DrawCubeTextureRec(texture, rec, vec, 2.0, 2.0, 2.0, rl.White)

		rl.DrawGrid(10, 1.0) // Draw a grid
		rl.EndMode3D()
		rl.DrawFPS(10, 10)
		rl.EndDrawing()
	}

	// De-Initialization
	rl.UnloadTexture(texture) // Unload texture
	rl.CloseWindow()          // Close window and OpenGL context
}

// DrawCubeTexture draws a textured cube
// NOTE: Cube position is the center position
func DrawCubeTexture(texture rl.Texture2D, position rl.Vector3, width, height, length float32, color rl.Color) {
	x := position.X
	y := position.Y
	z := position.Z

	// Set desired texture to be enabled while drawing following vertex data
	rl.SetTexture(texture.ID)

	// Vertex data transformation can be defined with the commented lines,
	// but in this example we calculate the transformed vertex data directly when calling rlVertex3f()
	// rl.PushMatrix()
	// NOTE: Transformation is applied in inverse order (scale -> rotate -> translate)
	//rl.Translatef(2.0, 0.0, 0.0)
	//rl.Rotatef(45, 0, 1, )
	//rl.Scalef(2.0, 2.0, 2.0)

	rl.Begin(rl.Quads)
	rl.Color4ub(color.R, color.G, color.B, color.A)
	// Front Face
	rl.Normal3f(0.0, 0.0, 1.0) // Normal Pointing Towards Viewer
	rl.TexCoord2f(0.0, 0.0)
	rl.Vertex3f(x-width/2, y-height/2, z+length/2) // Bottom Left Of The Texture and Quad
	rl.TexCoord2f(1.0, 0.0)
	rl.Vertex3f(x+width/2, y-height/2, z+length/2) // Bottom Right Of The Texture and Quad
	rl.TexCoord2f(1.0, 1.0)
	rl.Vertex3f(x+width/2, y+height/2, z+length/2) // Top Right Of The Texture and Quad
	rl.TexCoord2f(0.0, 1.0)
	rl.Vertex3f(x-width/2, y+height/2, z+length/2) // Top Left Of The Texture and Quad
	// Back Face
	rl.Normal3f(0.0, 0.0, -1.0) // Normal Pointing Away From Viewer
	rl.TexCoord2f(1.0, 0.0)
	rl.Vertex3f(x-width/2, y-height/2, z-length/2) // Bottom Right Of The Texture and Quad
	rl.TexCoord2f(1.0, 1.0)
	rl.Vertex3f(x-width/2, y+height/2, z-length/2) // Top Right Of The Texture and Quad
	rl.TexCoord2f(0.0, 1.0)
	rl.Vertex3f(x+width/2, y+height/2, z-length/2) // Top Left Of The Texture and Quad
	rl.TexCoord2f(0.0, 0.0)
	rl.Vertex3f(x+width/2, y-height/2, z-length/2) // Bottom Left Of The Texture and Quad
	// Top Face
	rl.Normal3f(0.0, 1.0, 0.0) // Normal Pointing Up
	rl.TexCoord2f(0.0, 1.0)
	rl.Vertex3f(x-width/2, y+height/2, z-length/2) // Top Left Of The Texture and Quad.
	rl.TexCoord2f(0.0, 0.0)
	rl.Vertex3f(x-width/2, y+height/2, z+length/2) // Bottom Left Of The Texture and Quad
	rl.TexCoord2f(1.0, 0.0)
	rl.Vertex3f(x+width/2, y+height/2, z+length/2) // Bottom Right Of The Texture and Quad
	rl.TexCoord2f(1.0, 1.0)
	rl.Vertex3f(x+width/2, y+height/2, z-length/2) // Top Right Of The Texture and Quad Bottom Face
	rl.Normal3f(0.0, -1.0, 0.0)                    // Normal Pointing Down
	rl.TexCoord2f(1.0, 1.0)
	rl.Vertex3f(x-width/2, y-height/2, z-length/2) // Top Right Of The Texture and Quad
	rl.TexCoord2f(0.0, 1.0)
	rl.Vertex3f(x+width/2, y-height/2, z-length/2) // Top Left Of The Texture and Quad
	rl.TexCoord2f(0.0, 0.0)
	rl.Vertex3f(x+width/2, y-height/2, z+length/2) // Bottom Left Of The Texture and Quad
	rl.TexCoord2f(1.0, 0.0)
	rl.Vertex3f(x-width/2, y-height/2, z+length/2) // Bottom Right Of The Texture and Quad
	// Right face
	rl.Normal3f(1.0, 0.0, 0.0) // Normal Pointing Right
	rl.TexCoord2f(1.0, 0.0)
	rl.Vertex3f(x+width/2, y-height/2, z-length/2) // Bottom Right Of The Texture and Quad
	rl.TexCoord2f(1.0, 1.0)
	rl.Vertex3f(x+width/2, y+height/2, z-length/2) // Top Right Of The Texture and Quad
	rl.TexCoord2f(0.0, 1.0)
	rl.Vertex3f(x+width/2, y+height/2, z+length/2) // Top Left Of The Texture and Quad
	rl.TexCoord2f(0.0, 0.0)
	rl.Vertex3f(x+width/2, y-height/2, z+length/2) // Bottom Left Of The Texture and Quad
	// Left Face
	rl.Normal3f(-1.0, 0.0, 0.0) // Normal Pointing Left
	rl.TexCoord2f(0.0, 0.0)
	rl.Vertex3f(x-width/2, y-height/2, z-length/2) // Bottom Left Of The Texture and Quad
	rl.TexCoord2f(1.0, 0.0)
	rl.Vertex3f(x-width/2, y-height/2, z+length/2) // Bottom Right Of The Texture and Quad
	rl.TexCoord2f(1.0, 1.0)
	rl.Vertex3f(x-width/2, y+height/2, z+length/2) // Top Right Of The Texture and Quad
	rl.TexCoord2f(0.0, 1.0)
	rl.Vertex3f(x-width/2, y+height/2, z-length/2) // Top Left Of The Texture and Quad

	rl.End()
	//rl.PopMatrix()

	rl.SetTexture(0)
}

// DrawCubeTextureRec draws a cube with texture piece applied to all faces
func DrawCubeTextureRec(texture rl.Texture2D, source rl.Rectangle, position rl.Vector3, width, height,
	length float32, color rl.Color) {

	x := position.X
	y := position.Y
	z := position.Z

	texWidth := float32(texture.Width)
	texHeight := float32(texture.Height)

	// Set desired texture to be enabled while drawing following vertex data
	rl.SetTexture(texture.ID)

	// We calculate the normalized texture coordinates for the desired texture-source-rectangle
	// It means converting from (tex.width, tex.height) coordinates to [0.0f, 1.0f] equivalent
	rl.Begin(rl.Quads)
	rl.Color4ub(color.R, color.G, color.B, color.A)

	// Front face
	rl.Normal3f(0.0, 0.0, 1.0)
	rl.TexCoord2f(source.X/texWidth, (source.Y+source.Height)/texHeight)
	rl.Vertex3f(x-width/2, y-height/2, z+length/2)
	rl.TexCoord2f((source.X+source.Width)/texWidth, (source.Y+source.Height)/texHeight)
	rl.Vertex3f(x+width/2, y-height/2, z+length/2)
	rl.TexCoord2f((source.X+source.Width)/texWidth, source.Y/texHeight)
	rl.Vertex3f(x+width/2, y+height/2, z+length/2)
	rl.TexCoord2f(source.X/texWidth, source.Y/texHeight)
	rl.Vertex3f(x-width/2, y+height/2, z+length/2)

	// Back face
	rl.Normal3f(0.0, 0.0, -1.0)
	rl.TexCoord2f((source.X+source.Width)/texWidth, (source.Y+source.Height)/texHeight)
	rl.Vertex3f(x-width/2, y-height/2, z-length/2)
	rl.TexCoord2f((source.X+source.Width)/texWidth, source.Y/texHeight)
	rl.Vertex3f(x-width/2, y+height/2, z-length/2)
	rl.TexCoord2f(source.X/texWidth, source.Y/texHeight)
	rl.Vertex3f(x+width/2, y+height/2, z-length/2)
	rl.TexCoord2f(source.X/texWidth, (source.Y+source.Height)/texHeight)
	rl.Vertex3f(x+width/2, y-height/2, z-length/2)

	// Top face
	rl.Normal3f(0.0, 1.0, 0.0)
	rl.TexCoord2f(source.X/texWidth, source.Y/texHeight)
	rl.Vertex3f(x-width/2, y+height/2, z-length/2)
	rl.TexCoord2f(source.X/texWidth, (source.Y+source.Height)/texHeight)
	rl.Vertex3f(x-width/2, y+height/2, z+length/2)
	rl.TexCoord2f((source.X+source.Width)/texWidth, (source.Y+source.Height)/texHeight)
	rl.Vertex3f(x+width/2, y+height/2, z+length/2)
	rl.TexCoord2f((source.X+source.Width)/texWidth, source.Y/texHeight)
	rl.Vertex3f(x+width/2, y+height/2, z-length/2)

	// Bottom face
	rl.Normal3f(0.0, -1.0, 0.0)
	rl.TexCoord2f((source.X+source.Width)/texWidth, source.Y/texHeight)
	rl.Vertex3f(x-width/2, y-height/2, z-length/2)
	rl.TexCoord2f(source.X/texWidth, source.Y/texHeight)
	rl.Vertex3f(x+width/2, y-height/2, z-length/2)
	rl.TexCoord2f(source.X/texWidth, (source.Y+source.Height)/texHeight)
	rl.Vertex3f(x+width/2, y-height/2, z+length/2)
	rl.TexCoord2f((source.X+source.Width)/texWidth, (source.Y+source.Height)/texHeight)
	rl.Vertex3f(x-width/2, y-height/2, z+length/2)

	// Right face
	rl.Normal3f(1.0, 0.0, 0.0)
	rl.TexCoord2f((source.X+source.Width)/texWidth, (source.Y+source.Height)/texHeight)
	rl.Vertex3f(x+width/2, y-height/2, z-length/2)
	rl.TexCoord2f((source.X+source.Width)/texWidth, source.Y/texHeight)
	rl.Vertex3f(x+width/2, y+height/2, z-length/2)
	rl.TexCoord2f(source.X/texWidth, source.Y/texHeight)
	rl.Vertex3f(x+width/2, y+height/2, z+length/2)
	rl.TexCoord2f(source.X/texWidth, (source.Y+source.Height)/texHeight)
	rl.Vertex3f(x+width/2, y-height/2, z+length/2)

	// Left face
	rl.Normal3f(-1.0, 0.0, 0.0)
	rl.TexCoord2f(source.X/texWidth, (source.Y+source.Height)/texHeight)
	rl.Vertex3f(x-width/2, y-height/2, z-length/2)
	rl.TexCoord2f((source.X+source.Width)/texWidth, (source.Y+source.Height)/texHeight)
	rl.Vertex3f(x-width/2, y-height/2, z+length/2)
	rl.TexCoord2f((source.X+source.Width)/texWidth, source.Y/texHeight)
	rl.Vertex3f(x-width/2, y+height/2, z+length/2)
	rl.TexCoord2f(source.X/texWidth, source.Y/texHeight)
	rl.Vertex3f(x-width/2, y+height/2, z-length/2)

	rl.End()

	rl.SetTexture(0)
}