render: Merge <group> into <model>.

* sly/render/model.scm (<model>): Add 'transform' and 'children' fields.
  (model-transform, model-children): New accessors.
  (make-model): Add 'transform' and 'children' keyword arguments.
  (set-transform-identity!): New procedure.
  (draw-model): Recursively draw model and all children.
  (model-paint, model-blend): Renamed.
  (paint, blend, group, group*, move, place): New procedures.
* sly/render/group.scm: Delete.
* Makefile.am (SOURCES): Remove it.
* examples/2048/2048.scm: Update example.
* examples/animation.scm: Likewise.
* examples/font.scm: Likewise.
* examples/joystick.scm: Likewise.
* examples/mines/mines.scm: Likewise.
* examples/simple.scm: Likewise.
* examples/tilemap.scm: Likewise.
* README.org (Example): Update sample code.

7 files changed, 75 insertions, 81 deletions

diff --git a/examples/2048/2048.scm b/examples/2048/2048.scm
index 73cb5f6..7bffe0b 100755
--- a/examples/2048/2048.scm
+++ b/examples/2048/2048.scm
@@ -37,7 +37,6 @@
              (sly render color)
              (sly render context)
              (sly render font)
-             (sly render group)
              (sly render model)
              (sly render sprite)
              (sly render texture)
@@ -324,14 +323,15 @@
          (label (assoc-ref tile-label-cache n))
          (label-color (tile-text-color n))
          (bg-color (tile-bg-color n)))
-    (group-move (vector2 (* x w) (* y h))
-                (make-group
-                 (cons (model-paint bg-color tile-sprite)
-                       (if (zero? n)
-                           '()
-                           (list (group-move (vector2 (/ w 2) (/ h 2))
-                                             (group (model-paint label-color
-                                                                 label))))))))))
+    (move (vector2 (* x w) (* y h))
+          (group*
+           (cons (paint bg-color tile-sprite)
+                 (if (zero? n)
+                     '()
+                     (list (move (vector2 (/ w 2) (/ h 2))
+                                 (group
+                                  (paint label-color
+                                         label))))))))))
 
 (define window-width 640)
 (define window-height 480)
@@ -347,7 +347,7 @@
 
 (define-signal tiles
   (signal-map (lambda (board)
-                (make-group
+                (group*
                  (append-map
                   (match-lambda
                    ((y (row ...))
@@ -361,24 +361,24 @@
 (define play-again-font (load-default-font 16))
 
 (define-signal status-message
-  (let ((play-again (model-paint black (label play-again-font
-                                              "Press N to play again"
-                                              #:anchor 'top-center)))
-        (game-over (model-paint black (label font "GAME OVER"
-                                             #:anchor 'bottom-center)))
-        (you-win (model-paint black (label font "YOU WIN!"
-                                           #:anchor 'bottom-center))))
+  (let ((play-again (paint black (label play-again-font
+                                        "Press N to play again"
+                                        #:anchor 'top-center)))
+        (game-over (paint black (label font "GAME OVER"
+                                       #:anchor 'bottom-center)))
+        (you-win (paint black (label font "YOU WIN!"
+                                     #:anchor 'bottom-center))))
     (signal-map
            (lambda (board)
              (let ((message (cond
                              ((board-lose? board) game-over)
                              ((board-win? board) you-win)
                              (else #f))))
-               (group-move (vector2 (/ board-width 2)
-                                    (/ board-height 2))
-                           (make-group (if message
-                                           (list message play-again)
-                                           '())))))
+               (move (vector2 (/ board-width 2)
+                              (/ board-height 2))
+                     (group* (if message
+                                 (list message play-again)
+                                 '())))))
            board)))
 
 (define instruction-font (load-default-font 16))
@@ -387,11 +387,11 @@
   "Use the arrow keys to join the numbers and get to the 2048 tile!")
 
 (define-signal instructions
-  (group-move (vector2 (/ board-width 2) (- window-height (vy center-pos)))
-              (group
-               (model-paint text-color-1
-                            (label instruction-font instruction-text
-                                   #:anchor 'top-center)))))
+  (move (vector2 (/ board-width 2) (- window-height (vy center-pos)))
+        (group
+         (paint text-color-1
+                (label instruction-font instruction-text
+                       #:anchor 'top-center)))))
 
 (define score-header-font (load-default-font 14))
 (define score-font (load-default-font 22))
@@ -408,13 +408,13 @@
     (signal-map (lambda (score timer)
                   (let ((score (label score-font (number->string score)
                                       #:anchor 'center)))
-                    (group-move (vector2 x (- window-height 28))
-                                (group
-                                 (model-paint text-color-1 header)
-                                 (group-move (position-tween timer)
-                                             (group
-                                              (model-paint (color-tween timer)
-                                                           score)))))))
+                    (move (vector2 x (- window-height 28))
+                          (group
+                           (paint text-color-1 header)
+                           (move (position-tween timer)
+                                 (group
+                                  (paint (color-tween timer)
+                                         score)))))))
                 score
                 (signal-drop (lambda (t) (> t duration))
                              0 (signal-since 1 score)))))
@@ -427,7 +427,7 @@
                (- board-width (/ board-width 4))))
 
 (define-signal 2048-scene
-  (signal-map (cut group-move center-pos <>)
+  (signal-map (cut move center-pos <>)
               (signal-map group instructions tiles score
                           best-score status-message)))
 
@@ -438,7 +438,7 @@
 
 (define (draw-2048 dt alpha)
   (signal-let ((scene 2048-scene))
-    (draw-group scene camera)))
+    (draw-model scene camera)))
 
 ;;;
 ;;; Initialization
diff --git a/examples/animation.scm b/examples/animation.scm
index cc84c27..ef736d2 100644
--- a/examples/animation.scm
+++ b/examples/animation.scm
@@ -22,7 +22,7 @@
              (sly math tween)
              (sly math vector)
              (sly render camera)
-             (sly render group)
+             (sly render model)
              (sly render sprite)
              (sly render tileset))
 
@@ -45,18 +45,15 @@
     (tween (compose floor lerp) (compose ease-linear ease-loop)
            0 frame-count (* frame-count frame-rate))))
 
-(define-signal timer
-  (signal-fold + 0 (signal-every 1)))
-
 (define-signal scene
   (signal-map (lambda (time)
-                (group-move (position-tween time)
-                            (group (vector-ref walk-cycle (frame-tween time)))))
-              timer))
+                (move (position-tween time)
+                      (vector-ref walk-cycle (frame-tween time))))
+              (signal-timer)))
 
 (define camera (orthographic-camera 640 480))
 
-(add-hook! draw-hook (lambda _ (draw-group (signal-ref scene) camera)))
+(add-hook! draw-hook (lambda _ (draw-model (signal-ref scene) camera)))
 
 (with-window (make-window #:title "Animation")
   (start-game-loop))
diff --git a/examples/font.scm b/examples/font.scm
index 177879e..b3fcfc3 100644
--- a/examples/font.scm
+++ b/examples/font.scm
@@ -24,7 +24,7 @@
              (sly render color)
              (sly render font)
              (sly render model)
-             (sly render group)
+             (sly render model)
              (sly input mouse))
 
 (load "common.scm")
@@ -34,21 +34,20 @@
 (define font (load-default-font 18))
 
 (define-signal message-label
-  (group-move (vector2 320 240)
-              (group
-               (label font "The quick brown fox jumped over the lazy dog."
-                      #:anchor 'center))))
+  (move (vector2 320 240)
+        (label font "The quick brown fox jumped over the lazy dog."
+               #:anchor 'center)))
 
 (define-signal fps-label
   (signal-map (lambda (fps)
                 (let ((text (format #f "FPS: ~d" fps)))
-                  (group-move (vector2 0 480) (group (label font text)))))
+                  (move (vector2 0 480) (label font text))))
               fps))
 
 (define-signal mouse-label
   (signal-map (lambda (p)
                 (let ((text (format #f "Mouse: (~d, ~d)" (vx p) (vy p))))
-                  (group-move (vector2 0 460) (group (label font text)))))
+                  (move (vector2 0 460) (label font text))))
               (signal-throttle 5 mouse-position)))
 
 (define-signal scene
@@ -56,7 +55,7 @@
 
 (define camera (orthographic-camera 640 480))
 
-(add-hook! draw-hook (lambda _ (draw-group (signal-ref scene) camera)))
+(add-hook! draw-hook (lambda _ (draw-model (signal-ref scene) camera)))
 
 (with-window (make-window #:title "Fonts")
   (start-game-loop))
diff --git a/examples/joystick.scm b/examples/joystick.scm
index 57955c9..7aa83c7 100644
--- a/examples/joystick.scm
+++ b/examples/joystick.scm
@@ -28,7 +28,6 @@
              (sly input joystick)
              (sly render camera)
              (sly render model)
-             (sly render group)
              (sly render sprite)
              (sly render texture)
              (sly render font))
@@ -56,8 +55,7 @@
 
 (define-signal caption
   (signal-map (lambda (text)
-                (group-move (vector2 -76 -90)
-                            (group (label font text))))
+                (move (vector2 -76 -90) (label font text)))
               (signal-merge
                (make-signal "Press a button")
                (button-caption-signal "Hello there" 0)
@@ -67,13 +65,12 @@
 
 (define-signal scene
   (signal-map (lambda (position caption)
-                (group-move position
-                            (group player caption)))
+                (move position (group player caption)))
               player-position caption))
 
 (define camera (orthographic-camera (vx resolution) (vy resolution)))
 
-(add-hook! draw-hook (lambda _ (draw-group (signal-ref scene) camera)))
+(add-hook! draw-hook (lambda _ (draw-model (signal-ref scene) camera)))
 
 (add-hook! joystick-axis-hook
            (lambda (which axis value)
diff --git a/examples/mines/mines.scm b/examples/mines/mines.scm
index 97d77b0..663e146 100644
--- a/examples/mines/mines.scm
+++ b/examples/mines/mines.scm
@@ -37,7 +37,6 @@
              (sly render camera)
              (sly render color)
              (sly render font)
-             (sly render group)
              (sly render model)
              (sly render sprite)
              (sly input keyboard)
@@ -332,24 +331,24 @@
     (lambda (tile)
       ;; A tile may or may not have an overlay, so we do a little
       ;; quasiquoting magic to build the right list.
-      (make-group
+      (group*
        `(,(tile-base-sprite tile)
          ,@(let ((overlay (tile-overlay-sprite tile)))
             (if overlay
-                (list (group-place offset (group overlay)))
+                (list (place offset (group overlay)))
                 '())))))))
 
 (define-signal board-view
   (signal-map (lambda (board)
                 (define (draw-column tile x)
-                  (group-move (vector2 (* x tile-size) 0)
-                              (draw-tile tile)))
+                  (move (vector2 (* x tile-size) 0)
+                        (draw-tile tile)))
 
                 (define (draw-row row y)
-                  (group-move (vector2 0 (* y tile-size))
-                              (make-group (enumerate-map draw-column row))))
+                  (move (vector2 0 (* y tile-size))
+                        (group* (enumerate-map draw-column row))))
 
-                (make-group (enumerate-map draw-row board)))
+                (group* (enumerate-map draw-row board)))
               board))
 
 (define-signal status-message
@@ -357,9 +356,9 @@
                 (define (make-message message)
                   (label font message #:anchor 'center))
 
-                (group-move
+                (move
                  (vector2 (/ (vx resolution) 2) (- (vy resolution) 64))
-                 (make-group
+                 (group*
                   (cond
                    ((board-lose? board)
                     (list (make-message "GAME OVER - Press N to play again")))
@@ -372,7 +371,7 @@
   (signal-map (lambda (board-view status center-position)
                 (group
                  status
-                 (group-move center-position board-view)))
+                 (move center-position board-view)))
               board-view status-message center-position))
 
 (define camera
@@ -382,7 +381,7 @@
                              #:clear-color tango-dark-plum)))
 
 (define (draw-scene dt alpha)
-  (draw-group (signal-ref scene) camera))
+  (draw-model (signal-ref scene) camera))
 
 ;;;
 ;;; Initialization
diff --git a/examples/simple.scm b/examples/simple.scm
index 9560f6f..1596cfe 100644
--- a/examples/simple.scm
+++ b/examples/simple.scm
@@ -17,20 +17,23 @@
 
 (use-modules (sly game)
              (sly window)
+             (sly utils)
              (sly math vector)
              (sly render camera)
-             (sly render group)
-             (sly render sprite))
+             (sly render model)
+             (sly render sprite)
+             (sly render color))
 
 (load "common.scm")
 
 (define scene
-  (group-move (vector2 320 240)
-              (group (load-sprite "images/p1_front.png"))))
+  (chain (load-sprite "images/p1_front.png")
+    (paint red)
+    (move (vector2 320 240))))
 
 (define camera (orthographic-camera 640 480))
 
-(add-hook! draw-hook (lambda _ (draw-group scene camera)))
+(add-hook! draw-hook (lambda _ (draw-model scene camera)))
 
 (with-window (make-window #:title "Simple Sprite Demo")
   (start-game-loop))
diff --git a/examples/tilemap.scm b/examples/tilemap.scm
index 1615c88..5e54bde 100644
--- a/examples/tilemap.scm
+++ b/examples/tilemap.scm
@@ -26,7 +26,6 @@
              (sly utils)
              (sly render camera)
              (sly render color)
-             (sly render group)
              (sly render model)
              (sly render mesh)
              (sly render shader)
@@ -91,15 +90,15 @@
      (225 225 176 242 65 65 65 65 65 65 65 65 65 65 65 65 65 65 65 65))))
 
 (define scene
-  (group-move (v- (vector2 320 240)
-                  (v* (vector2 tile-width tile-height)
-                      (vector2 10 15/2)))
-              (apply group (compile-tile-layer map-tiles 32 32))))
+  (move (v- (vector2 320 240)
+            (v* (vector2 tile-width tile-height)
+                (vector2 10 15/2)))
+        (group* (compile-tile-layer map-tiles 32 32))))
 
 (define camera
   (orthographic-camera 640 480))
 
-(add-hook! draw-hook (lambda _ (draw-group scene camera)))
+(add-hook! draw-hook (lambda _ (draw-model scene camera)))
 
 (with-window (make-window #:title "Tilemap")
   (start-game-loop))