From: Alexis Laferrière <alexis.laf@xymus.net>
Date: Tue, 6 Jun 2017 23:33:08 +0000 (-0400)
Subject: gamnit: enable dynamic window resizing on desktop
X-Git-Url: http://nitlanguage.org

gamnit: enable dynamic window resizing on desktop

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
---

diff --git a/lib/gamnit/cameras.nit b/lib/gamnit/cameras.nit
index 7183e6b..688082b 100644
--- a/lib/gamnit/cameras.nit
+++ b/lib/gamnit/cameras.nit
@@ -207,8 +207,8 @@ class UICamera
 	# Clipping wall the farthest of the camera, defaults to -100.0
 	var far: Float = -100.0 is writable
 
-	# Width in world units, defaults to the width in pixels of the screen
-	var width: Float = display.width.to_f is lazy
+	# Width in world units, calculated from `height` and the screen aspect ratio
+	fun width: Float do return height * display.aspect_ratio
 
 	# Height in world units, defaults to 1080.0
 	#
@@ -221,9 +221,7 @@ class UICamera
 	fun reset_height(height: nullable Float)
 	do
 		if height == null then height = display.height.to_f
-
 		self.height = height
-		self.width = height * display.aspect_ratio
 	end
 
 	# Convert the position `x, y` on screen, to UI coordinates
diff --git a/lib/gamnit/cameras_cache.nit b/lib/gamnit/cameras_cache.nit
index 08adc8f..852ac9b 100644
--- a/lib/gamnit/cameras_cache.nit
+++ b/lib/gamnit/cameras_cache.nit
@@ -110,12 +110,6 @@ redef class UICamera
 		mvp_matrix_cache = null
 	end
 
-	redef fun width=(value)
-	do
-		super
-		mvp_matrix_cache = null
-	end
-
 	redef fun height=(value)
 	do
 		super
diff --git a/lib/gamnit/depth/depth.nit b/lib/gamnit/depth/depth.nit
index f18f2eb..9b4be47 100644
--- a/lib/gamnit/depth/depth.nit
+++ b/lib/gamnit/depth/depth.nit
@@ -45,6 +45,7 @@ redef class App
 	# Draw all elements of `actors` and then call `frame_core_flat`
 	protected fun frame_core_depth(display: GamnitDisplay)
 	do
+		glViewport(0, 0, display.width, display.height)
 		frame_core_dynamic_resolution_before display
 
 		# Update cameras on both our programs
diff --git a/lib/gamnit/display.nit b/lib/gamnit/display.nit
index 6e7c58c..2b694c6 100644
--- a/lib/gamnit/display.nit
+++ b/lib/gamnit/display.nit
@@ -34,7 +34,7 @@ class GamnitDisplay
 	fun height: Int is abstract
 
 	# Aspect ratio of the screen, `width / height`
-	var aspect_ratio: Float is lazy do return width.to_f / height.to_f
+	fun aspect_ratio: Float do return width.to_f / height.to_f
 
 	# Is the cursor locked et the center of the screen?
 	var lock_cursor = false is writable
diff --git a/lib/gamnit/display_linux.nit b/lib/gamnit/display_linux.nit
index 634656b..15f5281 100644
--- a/lib/gamnit/display_linux.nit
+++ b/lib/gamnit/display_linux.nit
@@ -78,7 +78,7 @@ redef class GamnitDisplay
 			print_error "Failed to initialize SDL2 IMG: {sdl.error}"
 		end
 
-		var sdl_window = new SDLWindow(window_title.to_cstring, window_width, window_height, (new SDLWindowFlags).opengl)
+		var sdl_window = new SDLWindow(window_title.to_cstring, window_width, window_height, sdl_window_flags)
 		assert not sdl_window.address_is_null else
 			print_error "Failed to create SDL2 window: {sdl.error}"
 		end
@@ -97,7 +97,12 @@ redef class GamnitDisplay
 		return sdl_window
 	end
 
-	# Initialization flags passed to SDL2 mixer
+	# SDL2 window initialization flags
+	#
+	# The default value supports OpenGL and window resizing.
+	var sdl_window_flags: SDLWindowFlags = (new SDLWindowFlags).opengl.resizable is lazy, writable
+
+	# SDL2 mixer initialization flags
 	#
 	# Defaults to all available formats.
 	var mix_init_flags: MixInitFlags = mix.flac | mix.mod | mix.mp3 | mix.ogg is lazy, writable
diff --git a/lib/gamnit/flat.nit b/lib/gamnit/flat.nit
index cafac8a..5375929 100644
--- a/lib/gamnit/flat.nit
+++ b/lib/gamnit/flat.nit
@@ -41,8 +41,8 @@ import more_collections
 import performance_analysis
 
 import gamnit
-import gamnit::cameras_cache
 intrude import gamnit::cameras
+intrude import gamnit::cameras_cache
 import gamnit::dynamic_resolution
 import gamnit::limit_fps
 import gamnit::camera_control
@@ -294,7 +294,7 @@ redef class App
 	do
 		texture.load
 
-		var splash = new Sprite(texture, ui_camera.center)
+		var splash = new Sprite(texture, ui_camera.center.offset(0.0, 0.0, 0.0))
 		ui_sprites.add splash
 
 		var display = display
@@ -372,6 +372,17 @@ redef class App
 		if display != null then display.close
 	end
 
+	redef fun on_resize(display)
+	do
+		super
+
+		world_camera.mvp_matrix_cache = null
+		ui_camera.mvp_matrix_cache = null
+
+		# Update all sprites in the UI
+		for sprite in ui_sprites do sprite.needs_update
+	end
+
 	redef fun frame_core(display)
 	do
 		# Prepare to draw, clear buffers
diff --git a/lib/gamnit/gamnit.nit b/lib/gamnit/gamnit.nit
index 0d39f1e..fccf2ae 100644
--- a/lib/gamnit/gamnit.nit
+++ b/lib/gamnit/gamnit.nit
@@ -77,4 +77,9 @@ redef class App
 	# The instances passed as `event` may be freed (or overwritten),
 	# right after this method returns. They should not be preserved.
 	fun accept_event(event: InputEvent): Bool do return false
+
+	# The window has been resized by the user or system
+	#
+	# The framework handles resizing the viewport automatically.
+	fun on_resize(display: GamnitDisplay) do end
 end
diff --git a/lib/gamnit/gamnit_linux.nit b/lib/gamnit/gamnit_linux.nit
index e68ee8e..b0c4241 100644
--- a/lib/gamnit/gamnit_linux.nit
+++ b/lib/gamnit/gamnit_linux.nit
@@ -18,6 +18,7 @@ module gamnit_linux
 import sdl2::events
 
 intrude import gamnit
+intrude import display_linux
 
 redef class App
 	private var sdl_event_buffer = new SDLEventBuffer.malloc
@@ -33,6 +34,12 @@ redef class App
 
 			# Convert to an SDL event with data
 			var sdl_event = sdl_event_buffer.to_event
+			if sdl_event isa SDLWindowEvent and sdl_event.is_resized then
+				display.width = sdl_event.data1
+				display.height = sdl_event.data2
+				on_resize display
+			end
+
 			# Convert to `mnit::inputs` conforming objects
 			var gamnit_event = sdl_event.to_gamnit_event(sdl_event_buffer)
 			accept_event gamnit_event