flan/examples/shapes-basic-shapes.flan
Joseph Ferano a4c6b996ff def re-runs its initialiser, and defvar is renamed defonce
The trio the author decided on 2026-09-20 is now all built: def is CL's
defparameter — its initialiser runs on every daemon re-run, unguarded, so
an edited initialiser repaints the same storage on C-c C-c plus re-run —
defonce (Clojure's name for CL's defvar, per the author) initialises once
behind the .init~once. flag, and defconst stays the image.

One parse arm reads both forms; the difference is Ast.reinit, carried to
Tast.global's grerun. Emit.startup_plan gives a def no guard flag, and
Check.check_global lifts every def initialiser — zero and literal
included — into global/<n>, so the host's startup reaches it through the
function cell and a re-evaluated def swaps it (Session's def_inits;
Emit.redefinition declares the cell for a non-sibling target). The old
defvar spelling is refused with the rename and both compiling spellings,
and every program, test, doc and editor list is swept — except sand.flan,
the author's live WIP, whose seven defvar lines are flagged in FIX.org
and keep its three dependent tests red on this branch.
2026-09-21 07:12:04 +07:00

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;;;; raylib [shapes] example - basic shapes drawing
;;;;
;;;; examples/shapes/shapes_basic_shapes.c. Ported first of the shapes batch
;;;; because it is the widest single file in the category: six draw families
;;;; the corpus had never called — draw-circle-gradient, the two rectangle
;;;; gradients, draw-triangle and draw-triangle-lines, and all three of the
;;;; poly draws — in one frame, beside the four the core examples already
;;;; exercise. Every one of them came out of the generated half of the
;;;; bindings and none needed a new line anywhere; that is the result worth
;;;; recording, because the whole point of a committed generated.flan is that
;;;; a build with no FLAN_RAYLIB_H set can draw with all of it.
;;;;
;;;; What it is actually a test of. The gradient calls are the first thing in
;;;; the corpus to pass *two* Colors in one call, and draw-triangle is the
;;;; first to pass three Vector2s. A struct argument crosses the FFI by
;;;; pointer into a generated shim (vendor/raylib/raylib.flan's header note),
;;;; so the arity of that copying is what a call with several small structs in
;;;; a row puts under load. Nothing here can be asserted headless — every line
;;;; needs a GL context — so the check is the link and the screen, which is
;;;; what the Shapes comment in raylib.flan already says about this family.
;;;;
;;;; The one deliberate difference from the C: the C writes `screenWidth/4*2`
;;;; and `screenWidth/4.0f*3.0f` for the same column and gets 400 and 600 out
;;;; of integer and float division respectively. Both are written here as the
;;;; arithmetic they are, in the type the call wants, rather than copied with
;;;; a cast on the end — `(/ screen-width 5)` is an i32 division for the i32
;;;; parameters of draw-circle, and the poly centre is built from f32
;;;; literals because a Vector2 holds f32.
(import rl "vendor:raylib")
(defconst screen-width 800)
(defconst screen-height 450)
;; The three columns the C lays the shapes out in. The middle one is
;; screenWidth/4*2 and the right one screenWidth/4*3, which is 400 and 600.
(defconst col-left 160) ; screen-width / 5
(defconst col-mid 400)
(defconst col-right 600)
(defonce rotation f32)
(defn main [] ()
(rl/init-window screen-width screen-height
"raylib [shapes] example - basic shapes drawing")
(defer (rl/close-window))
(set rotation 0.0)
(rl/set-target-fps 60)
(until (rl/window-should-close?)
;; Update. The polygons spin; nothing else moves.
(set rotation (+ rotation 0.2))
;; Draw
(rl/with-drawing
(rl/clear-background rl/raywhite)
(rl/draw-text "some basic shapes available on raylib" 20 20 20 rl/darkgray)
;; Circles. The gradient one takes an inner and an outer colour and is the
;; first call in the corpus to pass two Colors at once.
(rl/draw-circle col-left 120 35.0 rl/darkblue)
(rl/draw-circle-gradient col-left 220 60.0 rl/green rl/skyblue)
(rl/draw-circle-lines col-left 340 80.0 rl/darkblue)
;; Rectangles. draw-rectangle-gradient-h runs the colour left to right;
;; the -v form runs it top to bottom and the -ex form takes all four
;; corners. The C uses the horizontal one here.
(rl/draw-rectangle (- col-mid 60) 100 120 60 rl/red)
(rl/draw-rectangle-gradient-h (- col-mid 90) 170 180 130 rl/maroon rl/gold)
;; raylib draws this with quads internally rather than with lines, which
;; is why its thickness does not follow the line width anywhere.
(rl/draw-rectangle-lines (- col-mid 40) 320 80 60 rl/orange)
;; Triangles. raylib wants the three vertices in counter-clockwise order
;; and draws nothing at all for a clockwise one, so the order here is not
;; cosmetic.
(rl/draw-triangle (rl/Vector2 {.x 600.0 .y 80.0})
(rl/Vector2 {.x 540.0 .y 150.0})
(rl/Vector2 {.x 660.0 .y 150.0})
rl/violet)
(rl/draw-triangle-lines (rl/Vector2 {.x 600.0 .y 160.0})
(rl/Vector2 {.x 580.0 .y 230.0})
(rl/Vector2 {.x 620.0 .y 230.0})
rl/darkblue)
;; Polygons, all three at the same centre and the same rotation, at three
;; radii, so the filled hexagon sits inside the two outlines.
(let [centre (rl/Vector2 {.x (f32 col-right) .y 330.0})]
(rl/draw-poly centre 6 80.0 rotation rl/brown)
(rl/draw-poly-lines centre 6 90.0 rotation rl/brown)
(rl/draw-poly-lines-ex centre 6 85.0 rotation 6.0 rl/beige))
;; The C draws every LINES-based shape together so raylib can batch them
;; into one pass. This last line is part of that comment and not an
;; afterthought, so it stays where the C has it.
(rl/draw-line 18 42 (- screen-width 18) 42 rl/black))))