v/vlib/gg/image.v

// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license that can be found in the LICENSE file.
module gg

import gx
import os
import sokol
import sokol.sapp
import sokol.sgl
import sokol.gfx
import stbi

pub struct Image {
pub mut:
	id int
	width       int
	height      int
	nr_channels int
	ok          bool
	data        voidptr
	ext         string
	simg_ok     bool
	simg        C.sg_image
	path string
}

fn C.sg_isvalid() bool

pub fn (mut ctx Context) create_image(file string) Image {
	if !C.sg_isvalid() {
		//ctx.image_queue << file
		stb_img := stbi.load(file)
		img := Image{
			width: stb_img.width
			height: stb_img.height
			nr_channels: stb_img.nr_channels
			ok: false
			data: stb_img.data
			ext: stb_img.ext
			path: file
			id: ctx.image_cache.len
		}
		ctx.image_cache << img
		return img
	}
	mut img := create_image(file)
	img.id = ctx.image_cache.len
	ctx.image_cache << img
	return img
}

// TODO remove this
fn create_image(file string) Image {
	if !os.exists(file) {
		println('gg.create_image(): file not found: $file')
		return Image{} // none
	}
	stb_img := stbi.load(file)
	mut img := Image{
		width: stb_img.width
		height: stb_img.height
		nr_channels: stb_img.nr_channels
		ok: stb_img.ok
		data: stb_img.data
		ext: stb_img.ext
		path: file
	}
	img.init_sokol_image()
	return img
}

pub fn create_image_from_memory(buf byteptr, bufsize int) Image {
	stb_img := stbi.load_from_memory(buf, bufsize)
	mut img := Image{
		width: stb_img.width
		height: stb_img.height
		nr_channels: stb_img.nr_channels
		ok: stb_img.ok
		data: stb_img.data
		ext: stb_img.ext
	}
	return img
}

pub fn create_image_from_byte_array(b []byte) Image {
	return create_image_from_memory(b.data, b.len)
}

pub fn (mut img Image) init_sokol_image() &Image {
	//println('\n init sokol image $img.path ok=$img.simg_ok')
	mut img_desc := C.sg_image_desc{
		width: img.width
		height: img.height
		num_mipmaps: 0
		wrap_u: .clamp_to_edge
		wrap_v: .clamp_to_edge
		label: &byte(0)
		d3d11_texture: 0
	}
	img_desc.content.subimage[0][0] = C.sg_subimage_content{
		ptr: img.data
		size: img.nr_channels * img.width * img.height
	}
	img.simg = C.sg_make_image(&img_desc)
	img.simg_ok = true
	img.ok = true
	return img
}

pub fn (ctx &Context) draw_image(x, y, width, height f32, img_ &Image) {
	img := ctx.image_cache[img_.id] // fetch the image from cache
	if !img.simg_ok {
		return
	}
	u0 := f32(0.0)
	v0 := f32(0.0)
	u1 := f32(1.0)
	v1 := f32(1.0)
	x0 := f32(x) * ctx.scale
	y0 := f32(y) * ctx.scale
	x1 := f32(x + width) * ctx.scale
	y1 := f32(y + height) * ctx.scale
	//
	sgl.load_pipeline(ctx.timage_pip)
	sgl.enable_texture()
	sgl.texture(img.simg)
	sgl.begin_quads()
	sgl.c4b(255, 255, 255, 255)
	sgl.v2f_t2f(x0, y0,	  u0, v0)
	sgl.v2f_t2f(x1, y0,	  u1, v0)
	sgl.v2f_t2f(x1, y1,	  u1, v1)
	sgl.v2f_t2f(x0, y1,	  u0, v1)
	sgl.end()
	sgl.disable_texture()
}

pub fn (ctx &Context) draw_image_by_id(x, y, width, height f32, id int) {
	img := ctx.image_cache[id]
	ctx.draw_image(x,y,width,height,img)
}