examples,os: add an os.asset module, use it to simplify code in examples/, by removing $if android { checks (#22281)

examples/2048/2048.v

@@ -1,7 +1,7 @@
 import gg
 import gx
 import math
-import os
+import os.asset
 import rand
 import time
 
@@ -899,10 +899,6 @@ fn init(mut app App) {
 fn main() {
 	mut app := &App{}
 	app.new_game()
-	mut font_path := os.resource_abs_path(os.join_path('..', 'assets', 'fonts', 'RobotoMono-Regular.ttf'))
-	$if android {
-		font_path = 'fonts/RobotoMono-Regular.ttf'
-	}
 	app.gg = gg.new_context(
 		bg_color:     app.theme.bg_color
 		width:        default_window_width
@@ -913,7 +909,7 @@ fn main() {
 		event_fn:     on_event
 		init_fn:      init
 		user_data:    app
-		font_path:    font_path
+		font_path:    asset.get_path('../assets', 'fonts/RobotoMono-Regular.ttf')
 	)
 	app.gg.run()
 }

examples/clock/clock.v

@@ -2,7 +2,6 @@
 // This is a small V example that was based off of the fireworks example.
 // Written by Stefan Schroeder in 2021 for the v project examples.
 // See LICENSE for license information.
-import os
 import gg
 import gx
 import math
@@ -147,13 +146,7 @@ fn on_init(mut app App) {
 
 fn main() {
 	println("Press 'q' to quit.")
-	mut font_path := os.resource_abs_path(os.join_path('..', 'assets', 'fonts', 'RobotoMono-Regular.ttf'))
-	$if android {
-		font_path = 'fonts/RobotoMono-Regular.ttf'
-	}
-
 	mut app := &App{}
-
 	app.gg = gg.new_context(
 		width:        design_size
 		height:       design_size
@@ -163,8 +156,6 @@ fn main() {
 		frame_fn:     on_frame
 		event_fn:     on_event
 		init_fn:      on_init
-		font_path:    font_path
 	)
-
 	app.gg.run()
 }

examples/fireworks/fireworks.v

@@ -1,4 +1,3 @@
-import os
 import objects
 import gg
 import gx
@@ -94,14 +93,8 @@ fn (mut app App) resize() {
 }
 
 fn main() {
-	mut font_path := os.resource_abs_path(os.join_path('..', 'assets', 'fonts', 'RobotoMono-Regular.ttf'))
-	$if android {
-		font_path = 'fonts/RobotoMono-Regular.ttf'
-	}
-
 	mut app := &App{}
 	app.ui = objects.get_params()
-
 	app.gg = gg.new_context(
 		width:        app.ui.width
 		height:       app.ui.height
@@ -110,8 +103,6 @@ fn main() {
 		user_data:    app
 		frame_fn:     on_frame
 		event_fn:     on_event
-		font_path:    font_path
 	)
-
 	app.gg.run()
 }

examples/flappylearning/game.v

@@ -2,11 +2,11 @@ module main
 
 import gg
 import gx
-import os
 import time
 import math
 import rand
 import neuroevolution
+import os.asset
 
 const win_width = 500
 const win_height = 512
@@ -173,10 +173,6 @@ fn (mut app App) update() {
 
 fn main() {
 	mut app := &App{}
-	mut font_path := os.resource_abs_path(os.join_path('..', 'assets', 'fonts', 'RobotoMono-Regular.ttf'))
-	$if android {
-		font_path = 'fonts/RobotoMono-Regular.ttf'
-	}
 	app.gg = gg.new_context(
 		bg_color:      gx.white
 		width:         win_width
@@ -187,7 +183,7 @@ fn main() {
 		event_fn:      on_event
 		user_data:     app
 		init_fn:       app.init_images_wrapper
-		font_path:     font_path
+		font_path:     asset.get_path('../assets', 'fonts/RobotoMono-Regular.ttf')
 	)
 	app.nv = neuroevolution.Generations{
 		population: 50
@@ -210,21 +206,10 @@ fn (mut app App) init_images_wrapper() {
 }
 
 fn (mut app App) init_images() ! {
-	$if android {
-		background := os.read_apk_asset('img/background.png')!
-		app.background = app.gg.create_image_from_byte_array(background)!
-		bird := os.read_apk_asset('img/bird.png')!
-		app.bird = app.gg.create_image_from_byte_array(bird)!
-		pipetop := os.read_apk_asset('img/pipetop.png')!
-		app.pipetop = app.gg.create_image_from_byte_array(pipetop)!
-		pipebottom := os.read_apk_asset('img/pipebottom.png')!
-		app.pipebottom = app.gg.create_image_from_byte_array(pipebottom)!
-	} $else {
-		app.background = app.gg.create_image(os.resource_abs_path('assets/img/background.png'))!
-		app.bird = app.gg.create_image(os.resource_abs_path('assets/img/bird.png'))!
-		app.pipetop = app.gg.create_image(os.resource_abs_path('assets/img/pipetop.png'))!
-		app.pipebottom = app.gg.create_image(os.resource_abs_path('assets/img/pipebottom.png'))!
-	}
+	app.background = app.gg.create_image_from_byte_array(asset.read_bytes('assets', 'img/background.png')!)!
+	app.bird = app.gg.create_image_from_byte_array(asset.read_bytes('assets', 'img/bird.png')!)!
+	app.pipetop = app.gg.create_image_from_byte_array(asset.read_bytes('assets', 'img/pipetop.png')!)!
+	app.pipebottom = app.gg.create_image_from_byte_array(asset.read_bytes('assets', 'img/pipebottom.png')!)!
 }
 
 fn frame(app &App) {

examples/gg/raven_text_rendering.v

@@ -2,7 +2,7 @@ module main
 
 import gg
 import gx
-import os
+import os.asset
 import math
 
 const win_width = 600
@@ -62,10 +62,6 @@ mut:
 
 fn main() {
 	mut app := &App{}
-	mut font_path := os.resource_abs_path(os.join_path('..', 'assets', 'fonts', 'RobotoMono-Regular.ttf'))
-	$if android {
-		font_path = 'fonts/RobotoMono-Regular.ttf'
-	}
 	app.gg = gg.new_context(
 		width:         win_width
 		height:        win_height
@@ -74,7 +70,8 @@ fn main() {
 		user_data:     app
 		bg_color:      bg_color
 		frame_fn:      frame
-		font_path:     font_path // window_user_ptr: ctx
+		font_path:     asset.get_path('../assets', 'fonts/RobotoMono-Regular.ttf')
+		// window_user_ptr: ctx
 		// native_rendering: true
 	)
 	app.gg.run()

examples/gg/rectangles.v

@@ -2,7 +2,7 @@ module main
 
 import gg
 import gx
-import os
+import os.asset
 
 const win_width = 600
 const win_height = 300
@@ -23,20 +23,12 @@ fn main() {
 		window_title:  'Rectangles'
 		frame_fn:      frame
 		user_data:     app
-		init_fn:       init_images
 	)
-	mut logo_path := os.resource_abs_path(os.join_path('..', 'assets', 'logo.png'))
-	$if android {
-		logo_path = 'logo.png'
-	}
+	logo_path := asset.get_path('../assets', 'logo.png')
 	app.image = app.gg.create_image(logo_path)!.id
 	app.gg.run()
 }
 
-fn init_images(mut app App) {
-	// app.image = gg.create_image('logo.png')
-}
-
 fn frame(app &App) {
 	app.gg.begin()
 	app.draw()

examples/gg/rotating_textured_quad.v

@@ -1,6 +1,6 @@
 import gg
 import gx
-import os
+import os.asset
 import sokol.sgl
 
 pub struct Window {
@@ -10,11 +10,7 @@ pub mut:
 }
 
 pub fn (mut window Window) init() {
-	image_path := $if android {
-		'logo.png'
-	} $else {
-		os.resource_abs_path('../assets/logo.png')
-	}
+	image_path := asset.get_path('../assets', 'logo.png')
 	window.img = window.ctx.create_image(image_path) or { panic(err) }
 }
 

examples/gg/stars.v

@@ -1,6 +1,6 @@
 module main
 
-import os
+import os.asset
 import gg
 import gx
 import rand
@@ -78,10 +78,7 @@ fn main() {
 }
 
 fn init_images(mut app App) {
-	mut logo_path := os.resource_abs_path(os.join_path('..', 'assets', 'logo.png'))
-	$if android {
-		logo_path = 'logo.png'
-	}
+	logo_path := asset.get_path('../assets', 'logo.png')
 	app.image = app.gg.create_image(logo_path) or { panic(err) }
 }
 

examples/sokol/06_obj_viewer/modules/obj/util.v

@@ -1,52 +1,24 @@
 module obj
 
 import os
+import os.asset
 
 // read a file as single lines
 pub fn read_lines_from_file(file_path string) []string {
-	mut path := ''
-	mut rows := []string{}
-	$if android {
-		path = 'models/' + file_path
-		bts := os.read_apk_asset(path) or {
-			eprintln('File [${path}] NOT FOUND!')
-			return rows
-		}
-		rows = bts.bytestr().split_into_lines()
-	} $else {
-		path = if os.exists(file_path) {
-			file_path
-		} else {
-			os.resource_abs_path('assets/models/${file_path}')
-		}
-		rows = os.read_lines(path) or {
-			eprintln('File [${path}] NOT FOUND! file_path: ${file_path}')
-			return rows
-		}
+	if os.exists(file_path) {
+		return os.read_lines(file_path) or { [] }
 	}
-	return rows
+	return read_bytes_from_file(file_path).bytestr().split_into_lines()
 }
 
 // read a file as []u8
 pub fn read_bytes_from_file(file_path string) []u8 {
-	mut path := ''
-	mut buffer := []u8{}
-	$if android {
-		path = 'models/' + file_path
-		buffer = os.read_apk_asset(path) or {
-			eprintln('Texture file: [${path}] NOT FOUND!')
-			exit(0)
-		}
-	} $else {
-		path = if os.exists(file_path) {
-			file_path
-		} else {
-			os.resource_abs_path('assets/models/${file_path}')
-		}
-		buffer = os.read_bytes(path) or {
-			eprintln('Texture file: [${path}] NOT FOUND!')
-			exit(0)
-		}
+	if os.exists(file_path) {
+		return os.read_bytes(file_path) or { [] }
+	}
+	mpath := 'models/${file_path}'
+	return asset.read_bytes('assets', mpath) or {
+		eprintln('Model file NOT FOUND: `${mpath}`')
+		exit(0)
 	}
-	return buffer
 }

examples/tetris/tetris.v

@@ -3,7 +3,7 @@
 // that can be found in the LICENSE file.
 module main
 
-import os
+import os.asset
 import rand
 import time
 import gx
@@ -157,10 +157,6 @@ fn frame(mut game Game) {
 
 fn main() {
 	mut game := &Game{}
-	mut fpath := os.resource_abs_path(os.join_path('..', 'assets', 'fonts', 'RobotoMono-Regular.ttf'))
-	$if android {
-		fpath = 'fonts/RobotoMono-Regular.ttf'
-	}
 	game.gg = gg.new_context(
 		bg_color:      gx.white
 		width:         win_width
@@ -170,7 +166,8 @@ fn main() {
 		user_data:     game
 		frame_fn:      frame
 		event_fn:      on_event
-		font_path:     fpath // wait_events: true
+		font_path:     asset.get_path('../assets', 'fonts/RobotoMono-Regular.ttf')
+		// wait_events: true
 	)
 	game.init_game()
 	game.gg.run() // Run the render loop in the main thread

vlib/os/asset/README.md

@@ -0,0 +1,11 @@
+# Asset
+
+The `asset` module provides a cross platform way to read assets, without cluttering
+the user code with comptime conditionals, like `$if ios {` or `$if android {` etc.
+
+Currently it supports Android assets, and desktop applications, that do not use
+archived/zipped files, but could be extended to support archived files too in the future.
+
+It relies on the assumption that each platform has a way to either read files, relative
+to the location of the executable, or a platform specific way, to package all asset files
+into the application archive/package/executable, that is then distributed to the end users.

vlib/os/asset/asset.v

@@ -0,0 +1,27 @@
+module asset
+
+import os
+
+// get_path returns a platform specific path, based on the given asset base folder and relative path
+// of a resource in it. On desktop systems, it returns a path relative to the location of the executable.
+// On Android, it will return just the relative_path segment, allowing you to later use os.read_apk_asset
+// to read from it.
+pub fn get_path(base_folder string, relative_path string) string {
+	$if android {
+		return relative_path
+	} $else {
+		return os.resource_abs_path(os.join_path(base_folder, relative_path))
+	}
+}
+
+// read_bytes will read all of the given asset, specified by its base_folder and relative path in it.
+// On Android, it will use os.read_apk_asset, relying that the asset base folder has been prepared, and
+// prepackaged inside your APK. On desktop systems, it will use the base_folder and relative_path, to
+// locate the file, in a way, that is relative to the executable.
+pub fn read_bytes(base_folder string, relative_path string) ![]u8 {
+	$if android {
+		return os.read_apk_asset(get_path(base_folder, relative_path))
+	} $else {
+		return os.read_bytes(get_path(base_folder, relative_path))
+	}
+}