examples: simpify text rendering examples

examples/gg/raven_text_rendering.v

@@ -0,0 +1,93 @@
+module main
+
+import gg
+import gx
+import os
+
+const (
+	win_width = 600
+	win_height = 700
+	bg_color = gx.white
+)
+
+const (
+text = '
+Once upon a midnight dreary, while I pondered, weak and weary,
+Over many a quaint and curious volume of forgotten lore—
+    While I nodded, nearly napping, suddenly there came a tapping,
+As of some one gently rapping, rapping at my chamber door.
+“’Tis some visitor,” I muttered, “tapping at my chamber door—
+            Only this and nothing more.”
+
+    Ah, distinctly I remember it was in the bleak December;
+And each separate dying ember wrought its ghost upon the floor.
+    Eagerly I wished the morrow;—vainly I had sought to borrow
+    From my books surcease of sorrow—sorrow for the lost Lenore—
+For the rare and radiant maiden whom the angels name Lenore—
+            Nameless here for evermore.
+
+    And the silken, sad, uncertain rustling of each purple curtain
+Thrilled me—filled me with fantastic terrors never felt before;
+    So that now, to still the beating of my heart, I stood repeating
+    “’Tis some visitor entreating entrance at my chamber door—
+Some late visitor entreating entrance at my chamber door;—
+            This it is and nothing more.”
+
+    Presently my soul grew stronger; hesitating then no longer,
+“Sir,” said I, “or Madam, truly your forgiveness I implore;
+    But the fact is I was napping, and so gently you came rapping,
+    And so faintly you came tapping, tapping at my chamber door,
+That I scarce was sure I heard you”—here I opened wide the door;—
+            Darkness there and nothing more.
+
+Deep into that darkness peering, long I stood there wondering, fearing,
+Doubting, dreaming dreams no mortal ever dared to dream before;
+    But the silence was unbroken, and the stillness gave no token,
+    And the only word there spoken was the whispered word, “Lenore?”
+This I whispered, and an echo murmured back the word, “Lenore!”—
+            Merely this and nothing more.
+
+    Back into the chamber turning, all my soul within me burning,
+Soon again I heard a tapping somewhat louder than before.
+    “Surely,” said I, “surely that is something at my window lattice;
+      Let me see, then, what thereat is, and this mystery explore—
+Let my heart be still a moment and this mystery explore;—
+            ’Tis the wind and nothing more!”
+'
+lines = text.split('\n')
+)
+
+
+struct App {
+mut:
+	gg &gg.Context
+}
+
+fn main() {
+	mut app := &App{}
+	app.gg = gg.new_context({
+		width: win_width
+		height: win_height
+		use_ortho: true // This is needed for 2D drawing
+		create_window: true
+		window_title: 'Empty window'
+		user_data: app
+		bg_color: bg_color
+		init_fn: init_gui
+		frame_fn: frame
+		font_path: os.resource_abs_path('../assets/fonts/RobotoMono-Regular.ttf')
+		//window_user_ptr: ctx
+	})
+	app.gg.run()
+}
+
+fn frame(mut app App) {
+	app.gg.begin()
+	mut y := 10
+	for line in lines {
+		app.gg.draw_text_def(10, y, line)
+		y += 30
+	}
+	app.gg.end()
+}
+