scene: Simplify scene nodes and meshes.

* sly/scene.scm (scene-node-positin, scene-node-scale,
  scene-node-rotation, interpolate): Delete.
  (with-texture-maybe): New macro.
  (draw-scene-node): Remove interpolation logic.  Add texture binding.
* sly/mesh.scm (mesh-texture): Delete.
  (make-mesh): Remove texture parameter.
  (draw-mesh): Remove texture binding.
* sly/shape.scm (make-cube): Wrap mesh in a scene node.
* sly/sprite.scm (make-sprite): Likewise.

4 files changed, 130 insertions, 129 deletions

diff --git a/sly/mesh.scm b/sly/mesh.scm
index c00d602..89e700c 100644
--- a/sly/mesh.scm
+++ b/sly/mesh.scm
@@ -17,8 +17,7 @@
 
 ;;; Commentary:
 ;;
-;; A mesh is a 2D/3D model comprised of a texture, shader, and vertex
-;; buffers.
+;; A mesh is a 2D/3D model comprised of a shader and vertex buffers.
 ;;
 ;;; Code:
 
@@ -157,14 +156,13 @@
 ;;;
 
 (define-record-type <mesh>
-  (%make-mesh vao length shader texture)
+  (%make-mesh vao length shader)
   mesh?
   (vao mesh-vao)
   (length mesh-length)
-  (shader mesh-shader)
-  (texture mesh-texture))
+  (shader mesh-shader))
 
-(define* (make-mesh #:optional #:key shader texture indices data)
+(define* (make-mesh #:optional #:key shader indices data)
   (let ((vao (generate-vertex-array)))
     (with-vertex-array vao
       (let loop ((data data))
@@ -175,7 +173,7 @@
            (loop rest))
           (() #f)))
       (bind-vertex-buffer (make-vertex-buffer indices #t)))
-    (%make-mesh vao (vector-length indices) shader texture)))
+    (%make-mesh vao (vector-length indices) shader)))
 
 (define (draw-mesh mesh uniforms)
   (define (draw)
@@ -192,6 +190,4 @@
                                  (signal-ref-maybe value)))))
               uniforms)
     (with-vertex-array (mesh-vao mesh)
-      (if (texture? (mesh-texture mesh))
-          (with-texture (mesh-texture mesh) (draw))
-          (draw)))))
+      (draw))))
diff --git a/sly/scene.scm b/sly/scene.scm
index a8b90b4..a06efd9 100644
--- a/sly/scene.scm
+++ b/sly/scene.scm
@@ -22,19 +22,21 @@
 ;;; Code:
 
 (define-module (sly scene)
+  #:use-module (ice-9 match)
   #:use-module (srfi srfi-9)
   #:use-module (srfi srfi-26)
   #:use-module (sly camera)
   #:use-module (sly mesh)
   #:use-module (sly quaternion)
   #:use-module (sly signal)
+  #:use-module (sly texture)
   #:use-module (sly transform)
   #:use-module (sly transition)
   #:use-module (sly math vector)
   #:export (scene-node
             make-scene-node
             scene-node?
-            scene-node-position scene-node-scale scene-node-rotation
+            scene-node-transform scene-node-texture
             scene-node-uniforms scene-node-children
             update-scene-node draw-scene-node
             make-scene
@@ -43,32 +45,32 @@
             update-scene draw-scene))
 
 (define-record-type <scene-node>
-  (%make-scene-node position scale rotation uniforms children)
+  (%make-scene-node transform texture uniforms children)
   scene-node?
-  (position scene-node-position)
-  (scale scene-node-scale)
-  (rotation scene-node-rotation)
+  (transform scene-node-transform)
+  (texture scene-node-texture)
   (uniforms scene-node-uniforms)
   (children scene-node-children))
 
 (define* (make-scene-node #:optional #:key
-                           (position (vector2 0 0))
-                           (scale 1)
-                           (rotation identity-quaternion)
-                           (uniforms '())
-                           (children '())
-                           #:allow-other-keys)
-  (%make-scene-node position scale rotation uniforms children))
+                          (transform identity-transform)
+                          (texture #f)
+                          (uniforms '())
+                          (children '())
+                          #:allow-other-keys)
+  (match children
+    ((or (children ...)
+         (= list children))
+     (%make-scene-node transform texture uniforms children))))
 
 (define-syntax-rule (scene-node (field val) ...)
   (apply make-scene-node
          (append (list (symbol->keyword 'field) val) ...)))
 
-(define (interpolate current prev alpha)
-  (if (or (not prev)
-          (equal? current prev))
-      current
-      (vector-interpolate prev current alpha)))
+(define-syntax-rule (with-texture-maybe texture body ...)
+  (if (texture? texture)
+      (with-texture texture body ...)
+      (begin body ...)))
 
 (define* (draw-scene-node node alpha transform #:optional (uniforms '()))
   (signal-let ((node node))
@@ -76,17 +78,14 @@
         (draw-mesh node `(("mvp" ,transform)
                           ,@uniforms))
         (signal-let ((children (scene-node-children node))
-                     (position (scene-node-position node))
-                     (%scale (scene-node-scale node))
-                     (rotation (scene-node-rotation node)))
-          (let ((node-transform (transform*
-                                 (translate position)
-                                 (scale %scale)
-                                 (quaternion->transform rotation))))
-            (for-each (cut draw-scene-node <> alpha
-                           (transform* transform node-transform)
-                           (scene-node-uniforms node))
-                      children))))))
+                     (local-transform (scene-node-transform node))
+                     (texture (scene-node-texture node)))
+          (with-texture-maybe texture
+            (let ((transform (transform* transform local-transform))
+                  ;; FIXME: properly merge uniform alists together.
+                  (uniforms (append uniforms (scene-node-uniforms node))))
+              (for-each (cut draw-scene-node <> alpha transform uniforms)
+                        children)))))))
 
 ;;;
 ;;; Scene
diff --git a/sly/shape.scm b/sly/shape.scm
index 8283875..b71f59c 100644
--- a/sly/shape.scm
+++ b/sly/shape.scm
@@ -24,6 +24,7 @@
 (define-module (sly shape)
   #:use-module (sly math)
   #:use-module (sly mesh)
+  #:use-module (sly scene)
   #:use-module (sly shader)
   #:use-module (sly texture)
   #:use-module (sly math vector)
@@ -32,88 +33,90 @@
 (define* (make-cube size #:optional #:key (texture #f)
                     (shader (load-default-shader)))
   (let ((half-size (half size)))
-    (make-mesh
-     #:shader shader
+    (make-scene-node
      #:texture texture
-     #:indices #(
-                 ;; Front
-                 0 3 2 0 2 1
-                   ;; Back
-                   4 6 7 4 5 6
-                   ;; Top
-                   8 11 10 8 10 9
-                   ;; Bottom
-                   12 14 15 12 13 14
-                   ;; Left
-                   16 19 18 16 18 17
-                   ;; Right
-                   20 22 23 20 21 22)
-     #:data `(("position" ,(vector
+     #:children
+     (make-mesh
+      #:shader shader
+      #:indices #(
+                  ;; Front
+                  0 3 2 0 2 1
+                  ;; Back
+                  4 6 7 4 5 6
+                  ;; Top
+                  8 11 10 8 10 9
+                  ;; Bottom
+                  12 14 15 12 13 14
+                  ;; Left
+                  16 19 18 16 18 17
+                  ;; Right
+                  20 22 23 20 21 22)
+      #:data `(("position" ,(vector
+                             ;; Front
+                             (vector3 (- half-size) (- half-size) (- half-size))
+                             (vector3 half-size (- half-size) (- half-size))
+                             (vector3 half-size half-size (- half-size))
+                             (vector3 (- half-size) half-size (- half-size))
+                             ;; Back
+                             (vector3 (- half-size) (- half-size) half-size)
+                             (vector3 half-size (- half-size) half-size)
+                             (vector3 half-size half-size half-size)
+                             (vector3 (- half-size) half-size half-size)
+                             ;; Top
+                             (vector3 (- half-size) half-size (- half-size))
+                             (vector3 half-size half-size (- half-size))
+                             (vector3 half-size half-size half-size)
+                             (vector3 (- half-size) half-size half-size)
+                             ;; Bottom
+                             (vector3 (- half-size) (- half-size) (- half-size))
+                             (vector3 half-size (- half-size) (- half-size))
+                             (vector3 half-size (- half-size) half-size)
+                             (vector3 (- half-size) (- half-size) half-size)
+                             ;; Left
+                             (vector3 (- half-size) (- half-size) (- half-size))
+                             (vector3 (- half-size) half-size (- half-size))
+                             (vector3 (- half-size) half-size half-size)
+                             (vector3 (- half-size) (- half-size) half-size)
+                             ;; Right
+                             (vector3 half-size (- half-size) (- half-size))
+                             (vector3 half-size half-size (- half-size))
+                             (vector3 half-size half-size half-size)
+                             (vector3 half-size (- half-size) half-size)))
+               ,@(if texture
+                     (let ((s1 (texture-s1 texture))
+                           (t1 (texture-t1 texture))
+                           (s2 (texture-s2 texture))
+                           (t2 (texture-t2 texture)))
+                       `(("tex"
+                          ,(vector
                             ;; Front
-                            (vector3 (- half-size) (- half-size) (- half-size))
-                            (vector3 half-size (- half-size) (- half-size))
-                            (vector3 half-size half-size (- half-size))
-                            (vector3 (- half-size) half-size (- half-size))
+                            (vector2 s1 t1)
+                            (vector2 s2 t1)
+                            (vector2 s2 t2)
+                            (vector2 s1 t2)
                             ;; Back
-                            (vector3 (- half-size) (- half-size) half-size)
-                            (vector3 half-size (- half-size) half-size)
-                            (vector3 half-size half-size half-size)
-                            (vector3 (- half-size) half-size half-size)
+                            (vector2 s1 t1)
+                            (vector2 s2 t1)
+                            (vector2 s2 t2)
+                            (vector2 s1 t2)
                             ;; Top
-                            (vector3 (- half-size) half-size (- half-size))
-                            (vector3 half-size half-size (- half-size))
-                            (vector3 half-size half-size half-size)
-                            (vector3 (- half-size) half-size half-size)
+                            (vector2 s1 t1)
+                            (vector2 s2 t1)
+                            (vector2 s2 t2)
+                            (vector2 s1 t2)
                             ;; Bottom
-                            (vector3 (- half-size) (- half-size) (- half-size))
-                            (vector3 half-size (- half-size) (- half-size))
-                            (vector3 half-size (- half-size) half-size)
-                            (vector3 (- half-size) (- half-size) half-size)
+                            (vector2 s1 t1)
+                            (vector2 s2 t1)
+                            (vector2 s2 t2)
+                            (vector2 s1 t2)
                             ;; Left
-                            (vector3 (- half-size) (- half-size) (- half-size))
-                            (vector3 (- half-size) half-size (- half-size))
-                            (vector3 (- half-size) half-size half-size)
-                            (vector3 (- half-size) (- half-size) half-size)
+                            (vector2 s1 t1)
+                            (vector2 s2 t1)
+                            (vector2 s2 t2)
+                            (vector2 s1 t2)
                             ;; Right
-                            (vector3 half-size (- half-size) (- half-size))
-                            (vector3 half-size half-size (- half-size))
-                            (vector3 half-size half-size half-size)
-                            (vector3 half-size (- half-size) half-size)))
-              ,@(if texture
-                   (let ((s1 (texture-s1 texture))
-                         (t1 (texture-t1 texture))
-                         (s2 (texture-s2 texture))
-                         (t2 (texture-t2 texture)))
-                     `(("tex"
-                        ,(vector
-                          ;; Front
-                          (vector2 s1 t1)
-                          (vector2 s2 t1)
-                          (vector2 s2 t2)
-                          (vector2 s1 t2)
-                          ;; Back
-                          (vector2 s1 t1)
-                          (vector2 s2 t1)
-                          (vector2 s2 t2)
-                          (vector2 s1 t2)
-                          ;; Top
-                          (vector2 s1 t1)
-                          (vector2 s2 t1)
-                          (vector2 s2 t2)
-                          (vector2 s1 t2)
-                          ;; Bottom
-                          (vector2 s1 t1)
-                          (vector2 s2 t1)
-                          (vector2 s2 t2)
-                          (vector2 s1 t2)
-                          ;; Left
-                          (vector2 s1 t1)
-                          (vector2 s2 t1)
-                          (vector2 s2 t2)
-                          (vector2 s1 t2)
-                          ;; Right
-                          (vector2 s1 t1)
-                          (vector2 s2 t1)
-                          (vector2 s2 t2)
-                          (vector2 s1 t2)))))
-                   '())))))
+                            (vector2 s1 t1)
+                            (vector2 s2 t1)
+                            (vector2 s2 t2)
+                            (vector2 s1 t2)))))
+                     '()))))))
diff --git a/sly/sprite.scm b/sly/sprite.scm
index 5b4ee81..644d766 100644
--- a/sly/sprite.scm
+++ b/sly/sprite.scm
@@ -34,6 +34,7 @@
   #:use-module (sly helpers)
   #:use-module (sly math)
   #:use-module (sly mesh)
+  #:use-module (sly scene)
   #:use-module (sly shader)
   #:use-module (sly signal)
   #:use-module (sly texture)
@@ -62,20 +63,22 @@ custom SHADER can be specified."
          (t1 (texture-t1 texture))
          (s2 (texture-s2 texture))
          (t2 (texture-t2 texture)))
-    (make-mesh
-     #:shader shader
+    (make-scene-node
      #:texture texture
-     #:indices #(0 3 2 0 2 1)
-     #:data `(("position" ,(vector
-                            (vector3 x1 y1 0)
-                            (vector3 x2 y1 0)
-                            (vector3 x2 y2 0)
-                            (vector3 x1 y2 0)))
-              ("tex" ,(vector
-                       (vector2 s1 t1)
-                       (vector2 s2 t1)
-                       (vector2 s2 t2)
-                       (vector2 s1 t2)))))))
+     #:children
+     (make-mesh
+      #:shader shader
+      #:indices #(0 3 2 0 2 1)
+      #:data `(("position" ,(vector
+                             (vector3 x1 y1 0)
+                             (vector3 x2 y1 0)
+                             (vector3 x2 y2 0)
+                             (vector3 x1 y2 0)))
+               ("tex" ,(vector
+                        (vector2 s1 t1)
+                        (vector2 s2 t1)
+                        (vector2 s2 t2)
+                        (vector2 s1 t2))))))))
 
 (define* (load-sprite file-name #:optional #:key (shader (load-default-shader))
                       (anchor 'center) (color white))