From 1fda9b4f42102e4319423f72de91aaaf299a4fbf Mon Sep 17 00:00:00 2001
From: ~keith <keith@keithhacks.cyou>
Date: Wed, 23 Mar 2022 18:16:40 +0000
Subject: [PATCH] stuff

---
 wh-engine.asd                                 |   2 +
 wh-engine/actor-macros.lisp                   |   1 +
 wh-engine/actor.lisp                          |   4 +-
 wh-engine/input/input-system.lisp             | 272 +++++++++++-------
 wh-engine/main.lisp                           |   8 +-
 wh-engine/render/drawable.lisp                |   8 +-
 wh-engine/render/render-system.lisp           |  48 ++--
 wh-engine/render/render-target.lisp           |  90 ++++++
 wh-engine/render/shader.lisp                  |  43 +++
 wh-engine/render/shaders/basic-frag.glsl      |  12 +
 wh-engine/render/shaders/basic-shader.lisp    |  34 +++
 wh-engine/render/shaders/basic-vert.glsl      |  15 +
 .../shaders/render-target-blit-frag.glsl      |  14 +
 .../shaders/render-target-blit-vert.glsl      |  10 +
 wh-engine/render/view.lisp                    |  83 ++----
 15 files changed, 435 insertions(+), 209 deletions(-)
 create mode 100644 wh-engine/render/render-target.lisp
 create mode 100644 wh-engine/render/shader.lisp
 create mode 100644 wh-engine/render/shaders/basic-frag.glsl
 create mode 100644 wh-engine/render/shaders/basic-shader.lisp
 create mode 100644 wh-engine/render/shaders/basic-vert.glsl
 create mode 100644 wh-engine/render/shaders/render-target-blit-frag.glsl
 create mode 100644 wh-engine/render/shaders/render-target-blit-vert.glsl

diff --git a/wh-engine.asd b/wh-engine.asd
index 65c7c81..3beec9e 100644
--- a/wh-engine.asd
+++ b/wh-engine.asd
@@ -18,7 +18,9 @@
                  (:file "serialization")
                  (:file "systems")
                  (:file "render/render-system")
+                 (:file "render/shader")
                  (:file "render/drawable")
+                 (:file "render/render-target")
                  (:file "render/view")
                  (:file "input/input-system")
                  (:file "main"))
diff --git a/wh-engine/actor-macros.lisp b/wh-engine/actor-macros.lisp
index 7cfcf3a..be08791 100644
--- a/wh-engine/actor-macros.lisp
+++ b/wh-engine/actor-macros.lisp
@@ -37,6 +37,7 @@
         finally (return (values other-forms make-params))))
 
 (define-new!-impl component (class it params)
+  (declare (ignore class))
   (loop for (key value) on params by #'cddr
         if (eq key :actor)
           collect `(o! ,value (add-component ,it)) into other-forms
diff --git a/wh-engine/actor.lisp b/wh-engine/actor.lisp
index ac6d57a..85fe0f7 100644
--- a/wh-engine/actor.lisp
+++ b/wh-engine/actor.lisp
@@ -298,8 +298,8 @@
 (defmethod world-matrix ((this actor))
   "The local-to-world-space transformation matrix for this actor."
   (if (o! this parent)
-      (m* (o! this parent world-matrix) (o! this matrix))
-      (o! this matrix)))
+      (nm* (o! this parent world-matrix) (o! this matrix))
+      (mcopy3 (o! this matrix))))
 
 (defmethod local-matrix ((this actor))
   "The world-to-local-space transformation matrix for this actor."
diff --git a/wh-engine/input/input-system.lisp b/wh-engine/input/input-system.lisp
index 9f98992..e283547 100644
--- a/wh-engine/input/input-system.lisp
+++ b/wh-engine/input/input-system.lisp
@@ -6,7 +6,8 @@
   (:import-from sb-ext
                 weak-pointer weak-pointer-p make-weak-pointer weak-pointer-value)
   (:import-from objective-lisp O!)
-  (:export))
+  (:export keypress make-keypress keypress-key keypress-controlp keypress-metap keypress-shiftp keypress-superp
+           keyspec))
 
 (in-package wh-engine/input)
 
@@ -16,22 +17,13 @@
 
 (defun input-system-update ()
   ())
-#|
-(defmacro setup-keycode-translation-table (&rest rest)
-  (let ((table (gensym)))
-    `(let ((,table (make-hash-table)))
-       (setf ,@(loop for x from #x21 to #x40
-                     nconc `((gethash ,x ,table) ,(code-char x)))
-             ,@(loop for x from #x5b to #x7a
-                     nconc `((gethash ,x ,table) ,(code-char x)))
-             ,@(loop for (k v) on rest by #'cddr
-                     nconc `((gethash ,k ,table) ,v)))
-       ,table)))
-|#
+
+(defvar *keyspec-parsing-table* nil)
 (defvar *keycode-translation-reverse-table* nil)
 (defun setup-keycode-translation-table (&rest rest)
   (let ((table (make-hash-table :size (+ (truncate (length rest) 2) 64)))
-        (reverse (make-hash-table :size (+ (truncate (length rest) 2) 64))))
+        (reverse (make-hash-table))
+        (parsing (make-hash-table :test #'equal)))
     (loop for x from #x21 to #x40
           do (setf (gethash x table) (code-char x)
                    (gethash (code-char x) reverse) x))
@@ -40,9 +32,18 @@
                    (gethash (code-char x) reverse) x))
     (loop for (k v) on rest by #'cddr
           do (setf (gethash k table) v)
+             (cond ((and (consp v) (keywordp (cdr v)))
+                    (setf (gethash (format nil "K-<~A>" (cdr v)) parsing) (cdr v)))
+                   ((and (consp v) (stringp (cdr v)))
+                    (setf (gethash (format nil "K-~A" (cdr v)) parsing) (cdr v)))
+                   ((keywordp v)
+                    (setf (gethash (format nil "<~A>" v) parsing) v))
+                   ((stringp v)
+                    (setf (gethash v parsing) v)))
           unless (gethash v reverse)
             do (setf (gethash v reverse) k))
     (setf *keycode-translation-reverse-table* reverse)
+    (setf *keyspec-parsing-table* parsing)
     table))
 (defvar *keycode-translation-table*
   (setup-keycode-translation-table #x08 :backspace
@@ -77,25 +78,25 @@
                                    #x40000051 :down
                                    #x40000052 :up
                                    #x40000053 :num-lock
-                                   #x40000054 '(:keypad #\/)
-                                   #x40000055 '(:keypad #\*)
-                                   #x40000056 '(:keypad #\-)
-                                   #x40000057 '(:keypad #\+)
-                                   #x40000058 '(:keypad :return)
-                                   #x40000059 '(:keypad #\1)
-                                   #x4000005A '(:keypad #\2)
-                                   #x4000005B '(:keypad #\3)
-                                   #x4000005C '(:keypad #\4)
-                                   #x4000005D '(:keypad #\5)
-                                   #x4000005E '(:keypad #\6)
-                                   #x4000005F '(:keypad #\7)
-                                   #x40000060 '(:keypad #\8)
-                                   #x40000061 '(:keypad #\9)
-                                   #x40000062 '(:keypad #\0)
-                                   #x40000063 '(:keypad #\.)
+                                   #x40000054 '(:keypad . #\/)
+                                   #x40000055 '(:keypad . #\*)
+                                   #x40000056 '(:keypad . #\-)
+                                   #x40000057 '(:keypad . #\+)
+                                   #x40000058 '(:keypad . :return)
+                                   #x40000059 '(:keypad . #\1)
+                                   #x4000005A '(:keypad . #\2)
+                                   #x4000005B '(:keypad . #\3)
+                                   #x4000005C '(:keypad . #\4)
+                                   #x4000005D '(:keypad . #\5)
+                                   #x4000005E '(:keypad . #\6)
+                                   #x4000005F '(:keypad . #\7)
+                                   #x40000060 '(:keypad . #\8)
+                                   #x40000061 '(:keypad . #\9)
+                                   #x40000062 '(:keypad . #\0)
+                                   #x40000063 '(:keypad . #\.)
                                    #x40000065 :application
                                    #x40000066 :power
-                                   #x40000067 '(:keypad #\=)
+                                   #x40000067 '(:keypad . #\=)
                                    #x40000068 :f13
                                    #x40000069 :f14
                                    #x4000006A :f15
@@ -122,8 +123,8 @@
                                    #x4000007F :mute
                                    #x40000080 :volume+
                                    #x40000081 :volume-
-                                   #x40000085 '(:keypad #\,)
-                                   #x40000086 '(:keypad :as400=)
+                                   #x40000085 '(:keypad . #\,)
+                                   #x40000086 '(:keypad . :as400=)
                                    #x40000099 :alt-erase
                                    #x4000009A :sys-req
                                    #x4000009B :cancel
@@ -142,46 +143,46 @@
                                    #x400000B3 :decimal-separator
                                    #x400000B4 :currency-unit
                                    #x400000B5 :currency-sub-unit
-                                   #x400000B6 '(:keypad #\()
-                                   #x400000B7 '(:keypad #\))
-                                   #x400000B8 '(:keypad #\{)
-                                   #x400000B9 '(:keypad #\})
-                                   #x400000BA '(:keypad :tab)
-                                   #x400000BB '(:keypad :backspace)
-                                   #x400000BC '(:keypad #\a)
-                                   #x400000BD '(:keypad #\b)
-                                   #x400000BE '(:keypad #\c)
-                                   #x400000BF '(:keypad #\d)
-                                   #x400000C0 '(:keypad #\e)
-                                   #x400000C1 '(:keypad #\f)
-                                   #x400000C2 '(:keypad :xor)
-                                   #x400000C3 '(:keypad #\^)
-                                   #x400000C4 '(:keypad #\%)
-                                   #x400000C5 '(:keypad #\<)
-                                   #x400000C6 '(:keypad #\>)
-                                   #x400000C7 '(:keypad #\&)
-                                   #x400000C8 '(:keypad "&&")
-                                   #x400000C9 '(:keypad #\|)
-                                   #x400000CA '(:keypad "||")
-                                   #x400000CB '(:keypad #\:)
-                                   #x400000CC '(:keypad #\#)
-                                   #x400000CD '(:keypad :space)
-                                   #x400000CE '(:keypad #\@)
-                                   #x400000CF '(:keypad #\!)
-                                   #x400000D0 '(:keypad :mem-store)
-                                   #x400000D1 '(:keypad :mem-recall)
-                                   #x400000D2 '(:keypad :mem-clear)
-                                   #x400000D3 '(:keypad :mem+)
-                                   #x400000D4 '(:keypad :mem-)
-                                   #x400000D5 '(:keypad :mem*)
-                                   #x400000D6 '(:keypad :mem/)
-                                   #x400000D7 '(:keypad #\±)
-                                   #x400000D8 '(:keypad :clear)
-                                   #x400000D9 '(:keypad :clear-entry)
-                                   #x400000DA '(:keypad :binary)
-                                   #x400000DB '(:keypad :octal)
-                                   #x400000DC '(:keypad :decimal)
-                                   #x400000DD '(:keypad :hexadecimal)
+                                   #x400000B6 '(:keypad . #\()
+                                   #x400000B7 '(:keypad . #\))
+                                   #x400000B8 '(:keypad . #\{)
+                                   #x400000B9 '(:keypad . #\})
+                                   #x400000BA '(:keypad . :tab)
+                                   #x400000BB '(:keypad . :backspace)
+                                   #x400000BC '(:keypad . #\a)
+                                   #x400000BD '(:keypad . #\b)
+                                   #x400000BE '(:keypad . #\c)
+                                   #x400000BF '(:keypad . #\d)
+                                   #x400000C0 '(:keypad . #\e)
+                                   #x400000C1 '(:keypad . #\f)
+                                   #x400000C2 '(:keypad . :xor)
+                                   #x400000C3 '(:keypad . #\^)
+                                   #x400000C4 '(:keypad . #\%)
+                                   #x400000C5 '(:keypad . #\<)
+                                   #x400000C6 '(:keypad . #\>)
+                                   #x400000C7 '(:keypad . #\&)
+                                   #x400000C8 '(:keypad . "&&")
+                                   #x400000C9 '(:keypad . #\|)
+                                   #x400000CA '(:keypad . "||")
+                                   #x400000CB '(:keypad . #\:)
+                                   #x400000CC '(:keypad . #\#)
+                                   #x400000CD '(:keypad . :space)
+                                   #x400000CE '(:keypad . #\@)
+                                   #x400000CF '(:keypad . #\!)
+                                   #x400000D0 '(:keypad . :mem-store)
+                                   #x400000D1 '(:keypad . :mem-recall)
+                                   #x400000D2 '(:keypad . :mem-clear)
+                                   #x400000D3 '(:keypad . :mem+)
+                                   #x400000D4 '(:keypad . :mem-)
+                                   #x400000D5 '(:keypad . :mem*)
+                                   #x400000D6 '(:keypad . :mem/)
+                                   #x400000D7 '(:keypad . #\±)
+                                   #x400000D8 '(:keypad . :clear)
+                                   #x400000D9 '(:keypad . :clear-entry)
+                                   #x400000DA '(:keypad . :binary)
+                                   #x400000DB '(:keypad . :octal)
+                                   #x400000DC '(:keypad . :decimal)
+                                   #x400000DD '(:keypad . :hexadecimal)
                                    ;; modifiers
                                    #x400000E0 :left-control
                                    #x400000E1 :left-shift
@@ -220,55 +221,104 @@
                                    #x4000011A :sleep
                                    ))
 
-(defun parse-keyspec (keyspec)
-  "Parse an Emacs-style key specification."
+(defstruct keypress
+  (key nil :type (or symbol character cons string null))
+  (controlp nil :type boolean)
+  (metap nil :type boolean)
+  (shiftp nil :type boolean)
+  (superp nil :type boolean))
+
+(defmacro keyspec (keyspec expr)
+  "Compare EXPR to an Emacs-style KEYSPEC."
   (declare (type simple-string keyspec))
-  ;; 'C-': control, 'M-': meta, 'S-': shift, 'X-': super, 'K-': keypad
-  (let* ((keypad-p nil)
+  (let* ((keypadp nil)
          (ks keyspec)
-         (modifiers (loop while (and (> (length ks) 2) (char= (schar ks 1) #\-))
-                          if (char= (schar ks 0) #\K)
-                            do (setf keypad-p t)
-                               (setf ks (subseq ks 2))
-                          else
-                            if (case (schar ks 0)
-                                 (#\C :control)
-                                 (#\M :meta)
-                                 (#\S :shift)
-                                 (#\X :super))
-                              collect it
-                              and do (setf ks (subseq ks 2))
-                          else do (loop-finish)))
-         (key (cond
-                ((= (length ks) 0)
-                 (error "Invalid keyspec ~S" keyspec))
-                ((= (length ks) 1)
-                 (if (upper-case-p (schar ks 0))
-                     (progn (setf modifiers (cons :shift modifiers))
-                           (char-downcase (schar ks 0)))
-                     (schar ks 0)))
-                ((string= ks "SPC") :space)
-                ((string= ks "RET") :return)
-                ((string= ks "ESC") :escape)
-                ((string= ks "DEL") :delete)
-                ((string= ks "BS") :backspace)
-                (t (read-from-string ks)))
-              ))
-    (values (if keypad-p `(:keypad ,key) key) modifiers)))
+         (invertp nil)
+         (var (gensym))
+         (tests
+           (loop while (and (> (length ks) 2) (or (char= (schar ks 1) #\-) (char= (schar ks 0) #\^)))
+                 if (char= (schar ks 0) #\K)
+                   do (setf keypadp t)
+                      (setf ks (subseq ks 2))
+                 else
+                   if (char= (schar ks 0) #\^)
+                     do (setf invertp t)
+                        (setf ks (subseq ks 1))
+                 else
+                   if (if invertp
+                          (case (schar ks 0)
+                            (#\C `(not (keypress-controlp ,var)))
+                            (#\M `(not (keypress-metap ,var)))
+                            (#\S `(not (keypress-shiftp ,var)))
+                            (#\X `(not (keypress-superp ,var))))
+                          (case (schar ks 0)
+                            (#\C `(keypress-controlp ,var))
+                            (#\M `(keypress-metap ,var))
+                            (#\S `(keypress-shiftp ,var))
+                            (#\X `(keypress-superp ,var))))
+                     collect it
+                     and do (setf ks (subseq ks 2))
+                            (setf invertp nil)
+                 else do (loop-finish)))
+         (key
+           (cond
+             ((= (length ks) 0)
+              (error "Invalid keyspec ~S" keyspec))
+             ((= (length ks) 1)
+              (if (upper-case-p (schar ks 0))
+                  (progn (push `(keypress-shiftp ,var) tests)
+                         (char-downcase (schar ks 0)))
+                  (schar ks 0)))
+             ((string= ks "SPC") :space)
+             ((string= ks "RET") :return)
+             ((string= ks "TAB") :tab)
+             ((string= ks "ESC") :escape)
+             ((string= ks "DEL") :delete)
+             ((string= ks "BS") :backspace)
+             (t (gethash (if keypadp (concatenate 'string "K-" ks) ks) *keyspec-parsing-table*)))))
+    `(let ((,var ,expr))
+       (and ,@tests (equal (keypress-key ,var) ,(if keypadp `(cons :keypad ,key) key))))
+    ))
+
+(defun translate-sdl-key-sym (key-sym)
+  "Translate an SDL key-sym to a wh-engine keypress value."
+  (let ((sdl-mod (sdl2:mod-value key-sym)))
+    (make-keypress :key (gethash (sdl2:sym-value key-sym) *keycode-translation-table*)
+                   :controlp (/= (logand sdl-mod #x00C0) 0)
+                   :metap (/= (logand sdl-mod #x0300) 0)
+                   :shiftp (/= (logand sdl-mod #x0003) 0)
+                   :superp (/= (logand sdl-mod #x0C00) 0))))
 
 (defun on-key-down (key-sym)
-  (format t "key-down: ~S (mod ~S)~%"
-          (gethash (sdl2:sym-value key-sym) *keycode-translation-table*)
-          (sdl2:mod-keywords (sdl2:mod-value key-sym))))
+  (let ((keypress (translate-sdl-key-sym key-sym)))
+    (format t "keyDN: ~S~%" keypress)
+    (when (keyspec "M-x" keypress)
+      (format t "-- Meta-x Key Detected --~%"))
+    ))
 
 (defun on-key-up (key-sym)
-  ())
+  (let ((keypress (translate-sdl-key-sym key-sym)))
+    (format t "keyUP: ~S~%" keypress)
+    ))
 
 (defun on-mouse-move (mouse-location mouse-delta mouse-state)
   ())
 
+;; FIXME slow as FUCK
 (defun on-mouse-down (mouse-location mouse-button)
-  ())
+  (let ((view (wh-engine:deref-pointer (first wh-engine/render::*world-views*))))
+    (loop for drawable-ptr in wh-engine/render::*world-drawables*
+          for drawable = (wh-engine:deref-pointer drawable-ptr)
+          when (and (o! drawable wh-engine:active-p) (o! drawable wh-engine:actor wh-engine:tree-active-p))
+            do (multiple-value-bind (box-min box-max)
+                   (wh-engine/render::transform-box (o! drawable wh-engine/render:culling-box)
+                                                    (o! drawable wh-engine:actor wh-engine:world-matrix)
+                                                    (o! view wh-engine/render:view-matrix))
+                 (if (and (v>= box-max mouse-location)
+                          (v<= box-min mouse-location))
+                     ;; click has occured.
+                     (format t "Click on: ~S with btn: ~S~%" (o! drawable wh-engine:actor) mouse-button))
+                 ))))
 
 (defun on-mouse-up (mouse-location mouse-button)
   ())
diff --git a/wh-engine/main.lisp b/wh-engine/main.lisp
index 18bb4cd..e143975 100644
--- a/wh-engine/main.lisp
+++ b/wh-engine/main.lisp
@@ -114,9 +114,9 @@
                       when handler
                         collect `(,(cdr handler)
                                   (vec2 (truncate mouse-x whe/render:*pixel-scale*)
-                                        (truncate mouse-y whe/render:*pixel-scale*))
+                                        (- wh-engine/render:*view-height* (truncate mouse-y whe/render:*pixel-scale*)))
                                   (vec2 (truncate delta-x whe/render:*pixel-scale*)
-                                        (truncate delta-y whe/render:*pixel-scale*))
+                                        (- (truncate delta-y whe/render:*pixel-scale*)))
                                   state)))
              (:mousebuttondown
               (:x mouse-x :y mouse-y :button button)
@@ -126,7 +126,7 @@
                       when handler
                         collect `(,(cdr handler)
                                   (vec2 (truncate mouse-x whe/render:*pixel-scale*)
-                                        (truncate mouse-y whe/render:*pixel-scale*))
+                                        (- wh-engine/render:*view-height* (truncate mouse-y whe/render:*pixel-scale*)))
                                   button)))
              (:mousebuttonup
               (:x mouse-x :y mouse-y :button button)
@@ -136,7 +136,7 @@
                       when handler
                         collect `(,(cdr handler)
                                   (vec2 (truncate mouse-x whe/render:*pixel-scale*)
-                                        (truncate mouse-y whe/render:*pixel-scale*))
+                                        (- wh-engine/render:*view-height* (truncate mouse-y whe/render:*pixel-scale*)))
                                   button)))
              (:joyaxismotion
               (:which joy-id :axis axis :value value)
diff --git a/wh-engine/render/drawable.lisp b/wh-engine/render/drawable.lisp
index 8be4d58..0c5535a 100644
--- a/wh-engine/render/drawable.lisp
+++ b/wh-engine/render/drawable.lisp
@@ -35,7 +35,7 @@
 (defmethod draw ((this drawable-test) view)
   (gl:color (vx4 (o! this colour)) (vy4 (o! this colour)) (vz4 (o! this colour)) (vw4 (o! this colour)))
   (gl:with-primitives :quads
-    (gl:vertex -0.5 -0.5  0.0 1.0)
-    (gl:vertex  0.5 -0.5  0.0 1.0)
-    (gl:vertex  0.5  0.5  0.0 1.0)
-    (gl:vertex -0.5  0.5  0.0 1.0)))
+    (gl:vertex -0.5 -0.5)
+    (gl:vertex  0.5 -0.5)
+    (gl:vertex  0.5  0.5)
+    (gl:vertex -0.5  0.5)))
diff --git a/wh-engine/render/render-system.lisp b/wh-engine/render/render-system.lisp
index abfa37f..2d04bd1 100644
--- a/wh-engine/render/render-system.lisp
+++ b/wh-engine/render/render-system.lisp
@@ -25,7 +25,15 @@
    ; methods
    view-point render-view render-drawable
 
-   *view-width* *view-height* *view-ppu* *pixel-scale*))
+   *view-width* *view-height* *view-ppu* *pixel-scale*
+
+   ;; render/render-target.lisp
+   render-target
+   ; properties
+   width height framebuffer renderbuffer render-texture
+   ; methods
+   bind-for-rendering
+   ))
 
 (in-package wh-engine/render)
 
@@ -58,40 +66,18 @@
   "Re-sort the *world-views* list by render pass."
   (sort *world-views* #'< :key (lambda (v) (o! (deref-pointer v) render-pass))))
 
-(let (framebuf renderbuf render-texture win-width win-height)
+(let (render-target win-width win-height)
   (defun render-system-init ()
     (setf win-width (* *view-width* *pixel-scale*)
           win-height (* *view-height* *pixel-scale*)
-          framebuf (gl:gen-framebuffer)
-          renderbuf (gl:gen-renderbuffer)
-          render-texture (gl:gen-texture))
+          render-target (make-instance 'render-target :width *view-width* :height *view-height*))
 
-    ;; set up framebuffer
-    (gl:bind-framebuffer :framebuffer framebuf)
-
-    (gl:bind-texture :texture-2d render-texture)
-    (gl:tex-image-2d :texture-2d 0 :rgba *view-width* *view-height* 0 :rgba :unsigned-byte (cffi:null-pointer))
-    (gl:tex-parameter :texture-2d :texture-wrap-s :clamp-to-edge)
-    (gl:tex-parameter :texture-2d :texture-wrap-t :clamp-to-edge)
+    ;; change render target mode
+    (gl:bind-texture :texture-2d (o! render-target render-texture))
     (gl:tex-parameter :texture-2d :texture-min-filter :nearest)
     (gl:tex-parameter :texture-2d :texture-mag-filter :nearest)
     (gl:bind-texture :texture-2d 0)
 
-    (gl:framebuffer-texture-2d :framebuffer :color-attachment0 :texture-2d render-texture 0)
-
-    (gl:bind-renderbuffer :renderbuffer renderbuf)
-    (gl:renderbuffer-storage :renderbuffer :depth24-stencil8 *view-width* *view-height*)
-    (gl:bind-renderbuffer :renderbuffer 0)
-
-    (gl:framebuffer-renderbuffer :framebuffer :depth-stencil-attachment :renderbuffer renderbuf)
-
-    ;; make sure it's valid
-    (let ((result (gl:check-framebuffer-status :framebuffer)))
-      (unless (gl::enum= result :framebuffer-complete)
-        (error "Failed to create framebuffer: ~S" result)))
-
-    (format t "texture-resident-p: ~S~%" (gl:texture-resident-p render-texture))
-
     ;; set up gl
     (gl:matrix-mode :projection)
     (gl:ortho 0 *view-width*
@@ -100,13 +86,11 @@
     (gl:matrix-mode :modelview)
     (gl:load-identity)
     (gl:clear-color 0.0 0.0 0.0 1.0)
-    (gl:clear :color-buffer)
-    (gl:clear :depth-buffer))
+    (gl:clear :color-buffer :depth-buffer :stencil-buffer))
 
   (defun render-system-update ()
     ;; draw to render texture
-    (gl:bind-framebuffer :framebuffer framebuf)
-    (gl:viewport 0 0 *view-width* *view-height*)
+    (o! render-target (bind-for-rendering))
     (gl:clear :color-buffer)
     (gl:enable :depth-test)
     (let ((render-pass nil))
@@ -126,7 +110,7 @@
     (gl:clear :color-buffer)
     (gl:disable :depth-test)
     (gl:enable :texture-2d)
-    (gl:bind-texture :texture-2d render-texture)
+    (gl:bind-texture :texture-2d (o! render-target render-texture))
     (gl:matrix-mode :modelview)
     (gl:load-identity)
 
diff --git a/wh-engine/render/render-target.lisp b/wh-engine/render/render-target.lisp
new file mode 100644
index 0000000..89d643b
--- /dev/null
+++ b/wh-engine/render/render-target.lisp
@@ -0,0 +1,90 @@
+;;;; wh-engine/render/render-target.lisp
+;;;; Render targets - structures that store a GL framebuffer, renderbuffer, and texture.
+(in-package wh-engine/render)
+
+(defclass render-target ()
+  ((width :documentation "The width in pixels of this render target."
+          :reader width
+          :type fixnum
+          :initarg :width
+          :initform *view-width*)
+   (height :documentation "The height in pixels of this render target."
+           :reader height
+           :type fixnum
+           :initarg :height
+           :initform *view-height*)
+   (depth-texture-p :documentation "Whether or not to render depth (and stencil) information to a texture."
+                    :reader depth-texture-p
+                    :type boolean
+                    :initarg :depth-texture-p
+                    :initform nil)
+   (framebuffer :documentation "The GL framebuffer associated with this render target."
+                :reader framebuffer
+                :type (or fixnum null)
+                :initform nil)
+   (renderbuffer :documentation "The GL renderbuffer associated with this render target."
+                 :reader renderbuffer
+                 :type (or fixnum null)
+                 :initform nil)
+   (depth-texture :documentation "The GL texture containing the depth and stencil output for this render target."
+                  :reader depth-texture
+                  :type (or fixnum null)
+                  :initform nil)
+   (render-texture :documentation "The GL render texture containing the output of this render target."
+                   :reader render-texture
+                   :type (or fixnum null)
+                   :initform nil))
+  (:documentation "Stores a GL framebuffer, and its associated renderbuffer and output texture."))
+
+(defmethod make-load-form ((this render-target) &optional environment)
+  (declare (ignore environment))
+  `(make-instance ',(class-name (class-of this))
+                  :width ,(o! this width) :height ,(o! this height)
+                  :depth-texture-p ,(o! this depth-texture-p)))
+
+(defmethod initialize-instance :after ((this render-target) &key)
+  ;; create render texture
+  (setf (o! this :slot render-texture) (gl:gen-texture))
+  (gl:bind-texture :texture-2d (o! this :slot render-texture))
+  (gl:tex-image-2d :texture-2d 0 :rgba
+                   (o! this :slot width) (o! this :slot height)
+                   0 :rgba :unsigned-byte (cffi:null-pointer))
+  (gl:tex-parameter :texture-2d :texture-wrap-s :clamp-to-edge)
+  (gl:tex-parameter :texture-2d :texture-wrap-t :clamp-to-edge)
+  (gl:tex-parameter :texture-2d :texture-min-filter :linear)
+  (gl:tex-parameter :texture-2d :texture-mag-filter :linear)
+  (gl:bind-texture :texture-2d 0)
+
+  (if (o! this depth-texture-p)
+      (progn
+        ;; create depth texture
+        (setf (o! this :slot depth-texture) (gl:gen-texture))
+        (gl:bind-texture :texture-2d (o! this :slot depth-texture))
+        (gl:tex-image-2d :texture-2d 0 :depth24-stencil8
+                         (o! this :slot width) (o! this :slot height)
+                         0 :depth-stencil :unsigned-int-24-8 (cffi:null-pointer))
+        (gl:tex-parameter :texture-2d :texture-wrap-s :clamp-to-edge)
+        (gl:tex-parameter :texture-2d :texture-wrap-t :clamp-to-edge)
+        (gl:tex-parameter :texture-2d :texture-min-filter :linear)
+        (gl:tex-parameter :texture-2d :texture-mag-filter :linear)
+        (gl:bind-texture :texture-2d 0))
+      (progn
+        ;; create renderbuffer
+        (setf (o! this :slot renderbuffer) (gl:gen-renderbuffer))
+        (gl:bind-renderbuffer :renderbuffer (o! this :slot renderbuffer))
+        (gl:renderbuffer-storage :renderbuffer :depth24-stencil8 (o! this :slot width) (o! this :slot height))
+        (gl:bind-renderbuffer :renderbuffer 0)))
+
+  ;; create framebuffer
+  (setf (o! this :slot framebuffer) (gl:gen-framebuffer))
+  (gl:bind-framebuffer :framebuffer (o! this :slot framebuffer))
+  (gl:framebuffer-texture-2d :framebuffer :color-attachment0 :texture-2d (o! this :slot render-texture) 0)
+  (if (o! this depth-texture-p)
+      (gl:framebuffer-texture-2d :framebuffer :depth-stencil-attachment :texture-2d (o! this :slot depth-texture) 0)
+      (gl:framebuffer-renderbuffer :framebuffer :depth-stencil-attachment :renderbuffer (o! this :slot renderbuffer)))
+
+  (gl:bind-framebuffer :framebuffer 0))
+
+(defmethod bind-for-rendering ((this render-target))
+  (gl:bind-framebuffer :framebuffer (o! this framebuffer))
+  (gl:viewport 0 0 (o! this width) (o! this height)))
diff --git a/wh-engine/render/shader.lisp b/wh-engine/render/shader.lisp
new file mode 100644
index 0000000..1347452
--- /dev/null
+++ b/wh-engine/render/shader.lisp
@@ -0,0 +1,43 @@
+;;;; wh-engine/render/shader.lisp
+;;;; Lisp class for holding & handling shaders.
+;; (in-package wh-engine/render)
+
+(defun replace-cross-referenced-vars (forms vars replace-fun)
+  (loop for elt on forms
+        for form = (car elt)
+        if (symbolp form)
+          do (let ((var-entry (find form vars :key #'car)))
+               (when var-entry
+                 (rplaca elt (funcall replace-fun var-entry))))
+        else if (consp form)
+               do (collect-cross-referenced-vars (cdr form))))
+
+(defun transpile-shader (name &key
+                                version
+                                ((:in vert-inputs))
+                                ((:inter inter-vars))
+                                ((:out frag-outputs))
+                                ((:uniform uniform-vars))
+                                ((:vert vert-body))
+                                ((:frag frag-body)))
+  "Translate Lisp shader code to GLSL."
+  (list (collect-shader-vars vert-body)
+        (collect-shader-vars frag-body)))
+
+(defmacro define-shader (name (&key
+                                 ((:in (&rest vert-inputs)) ())
+                                 ((:inter (&rest inter-vars)) ())
+                                 ((:out (&rest frag-outputs)) ())
+                                 ((:uniform (&rest uniform-vars)) ()))
+                         &key
+                           ((:vert (&body vert-body)))
+                           ((:frag (&body frag-body)))
+                           version)
+  "Define a GLSL shader with Lisp code."
+  `(defparameter ,name (transpile-shader ',name
+                                         :version ,version
+                                         :in ',vert-inputs
+                                         :inter ',inter-vars
+                                         :out ',frag-outputs
+                                         :uniform ',uniform-vars
+                                         :vert ',vert-body :frag ',frag-body)))
diff --git a/wh-engine/render/shaders/basic-frag.glsl b/wh-engine/render/shaders/basic-frag.glsl
new file mode 100644
index 0000000..fd8db03
--- /dev/null
+++ b/wh-engine/render/shaders/basic-frag.glsl
@@ -0,0 +1,12 @@
+#version 330 core
+
+in vec2 uv;
+
+out vec4 FragColour;
+
+uniform sampler2D mainTex;
+uniform vec4 colour;
+
+void main() {
+	FragColour = texture(mainTex, uv) * colour;
+}
diff --git a/wh-engine/render/shaders/basic-shader.lisp b/wh-engine/render/shaders/basic-shader.lisp
new file mode 100644
index 0000000..9cd64d1
--- /dev/null
+++ b/wh-engine/render/shaders/basic-shader.lisp
@@ -0,0 +1,34 @@
+;;;; basic-shader.lisp (Lisp shader code)
+
+#|
+(define-shader basic-shader
+  (:version 330)
+  (:vertex-shader
+   :in ((vert-pos :type :vec3 :location 0)
+        (vert-uv :type :vec2 :location 1))
+   :out ((uv :type :vec2))
+   :uniform ((model :type :mat4)
+             (view :type :mat4)
+             (proj :type :mat4))
+   :main ((setf *position* (* proj view model (vec4 vert-pos 1.0)))
+          (setf uv vert-uv)))
+  (:fragment-shader
+   :in ((uv :type :vec2))
+   :out ((*frag-colour* :type :vec4))
+   :uniform ((main-tex :type :sampler-2d)
+             (colour :type :vec4))
+   :main ((setf *frag-colour* (* (sample-texture main-tex uv) colour)))))
+|#
+
+(define-shader basic-shader
+    (:in ((vert-pos :type :vec3 :location 0)
+          (vert-uv :type :vec2 :location 1))
+     :out ((*frag-colour* :type :vec4))
+     :uniform ((model :type :mat4)
+               (view :type :mat4)
+               (proj :type :mat4)
+               (main-tex :type :sampler-2d)
+               (colour :type :vec4)))
+  :version 330
+  :vert ((setf *position* (* proj view model (vec4 vert-pos 1.0))))
+  :frag ((setf *frag-colour* (* (sample-texture main-tex vert-uv) colour))))
diff --git a/wh-engine/render/shaders/basic-vert.glsl b/wh-engine/render/shaders/basic-vert.glsl
new file mode 100644
index 0000000..016881c
--- /dev/null
+++ b/wh-engine/render/shaders/basic-vert.glsl
@@ -0,0 +1,15 @@
+#version 330 core
+
+layout (location = 0) in vec3 vert_pos;
+layout (location = 1) in vec2 vert_uv;
+
+out vec2 uv;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 proj;
+
+void main() {
+	gl_Position = proj * view * model * vec4(vert_pos, 1.0);
+	uv = vert_uv;
+}
diff --git a/wh-engine/render/shaders/render-target-blit-frag.glsl b/wh-engine/render/shaders/render-target-blit-frag.glsl
new file mode 100644
index 0000000..c39320b
--- /dev/null
+++ b/wh-engine/render/shaders/render-target-blit-frag.glsl
@@ -0,0 +1,14 @@
+#version 330 core
+
+in vec2 uv;
+
+out vec4 FragColour;
+out float gl_FragDepth;
+
+uniform sampler2D mainTex;
+uniform sampler2DShadow depthTex;
+
+void main() {
+	FragColour = texture(mainTex, uv);
+	gl_FragDepth = texture(depthTex, uv);
+}
diff --git a/wh-engine/render/shaders/render-target-blit-vert.glsl b/wh-engine/render/shaders/render-target-blit-vert.glsl
new file mode 100644
index 0000000..f66d6f8
--- /dev/null
+++ b/wh-engine/render/shaders/render-target-blit-vert.glsl
@@ -0,0 +1,10 @@
+#version 330 core
+
+layout (location = 0) in vec2 vert_pos;
+
+out vec2 uv;
+
+void main() {
+	gl_Position = vec4(vert_pos, 0.0, 1.0);
+	uv = vert_pos;
+}
diff --git a/wh-engine/render/view.lisp b/wh-engine/render/view.lisp
index d5b53ea..85cdf8d 100644
--- a/wh-engine/render/view.lisp
+++ b/wh-engine/render/view.lisp
@@ -17,18 +17,10 @@
            :type boolean
            :initarg :cull-p
            :initform t)
-   (framebuffer :documentation "The GL framebuffer this view renders to."
-                :reader framebuffer
-                :type (or fixnum null)
-                :initform nil)
-   (renderbuffer :documentation "The GL renderbuffer this view renders depth & stencil data to."
-                 :reader renderbuffer
-                 :type (or fixnum null)
-                 :initform nil)
-   (render-texture :documentation "The GL render texture this view renders color data to."
-                   :reader render-texture
-                   :type (or fixnum null)
-                   :initform nil))
+   (render-target :documentation "The render target this view renders to."
+                  :reader render-target
+                  :type (or render-target null)
+                  :initform nil))
   (:documentation "Defines a view into the scene, and rendering settings for objects drawn by the view."))
 
 (defmethod (setf render-pass) (new-val (this view))
@@ -37,45 +29,14 @@
   (sort-world-views))
 
 (defmethod resume :after ((this view))
-  ;; create render texture & framebuffer
-  (unless (and (o! this render-texture) (gl:texture-resident-p (o! this render-texture))
-               (o! this renderbuffer) (gl:is-renderbuffer (o! this renderbuffer))
-               (o! this framebuffer) (gl:is-framebuffer (o! this framebuffer)))
-    ;; ensure the old ones are deleted if they exist
-    (when (o! this framebuffer)
-      (gl:delete-framebuffers (list (o! this framebuffer))))
-    (when (o! this render-texture)
-      (gl:delete-texture (o! this render-texture)))
-    (when (o! this renderbuffer)
-      (gl:delete-renderbuffers (list (o! this renderbuffer))))
-    ;; create render texture
-    (setf (o! this :slot render-texture) (gl:gen-texture))
-    (gl:bind-texture :texture-2d (o! this render-texture))
-    (gl:tex-image-2d :texture-2d 0 :rgba
-                     *view-width* *view-height*
-                     0 :rgba :unsigned-byte (cffi:null-pointer))
-    (gl:tex-parameter :texture-2d :texture-wrap-s :clamp-to-edge)
-    (gl:tex-parameter :texture-2d :texture-wrap-t :clamp-to-edge)
-    (gl:tex-parameter :texture-2d :texture-min-filter :linear)
-    (gl:tex-parameter :texture-2d :texture-mag-filter :linear)
-    (gl:bind-texture :texture-2d 0)
-    ;; create renderbuffer
-    (setf (o! this :slot renderbuffer) (gl:gen-renderbuffer))
-    (gl:bind-renderbuffer :renderbuffer (o! this renderbuffer))
-    (gl:renderbuffer-storage :renderbuffer :depth24-stencil8 *view-width* *view-height*)
-    (gl:bind-renderbuffer :renderbuffer 0)
-    ;; create framebuffer
-    (setf (o! this :slot framebuffer) (gl:gen-framebuffer))
-    (gl:bind-framebuffer :framebuffer (o! this framebuffer))
-    (gl:framebuffer-texture-2d :framebuffer :color-attachment0 :texture-2d (o! this render-texture) 0)
-    (gl:framebuffer-renderbuffer :framebuffer :depth-stencil-attachment :renderbuffer (o! this renderbuffer))
-    (gl:bind-framebuffer :framebuffer 0)
-    ))
+  (unless (o! this render-target)
+    (setf (o! this :slot render-target) (new! render-target :width *view-width* :height *view-height*))))
 
 (defmethod activate :after ((this view) &key)
   ; Register
-  (pushnew (make-weak-pointer this) *world-views*)
-  (sort-world-views))
+  (when (o! this actor tree-active-p)
+    (pushnew (make-weak-pointer this) *world-views*)
+    (sort-world-views)))
 
 (defmethod destroy :before ((this view))
   (unless (o! this destroyed-p)
@@ -123,18 +84,28 @@
               do (o! this (render-drawable drawable view-matrix)))
     ))
 
+(defun transform-box (box drawable-matrix view-matrix)
+  (with-vec2 (ax ay) (car box)
+    (with-vec2 (bx by) (cdr box)
+      (let ((box-a (vxy-trunc (n*m view-matrix
+                                   (m* drawable-matrix (vec3 ax ay 1)))))
+            (box-b (vxy-trunc (n*m view-matrix
+                                   (m* drawable-matrix (vec3 bx by 1)))))
+            (box-ab (vxy-trunc (n*m view-matrix
+                                    (m* drawable-matrix (vec3 ax by 1)))))
+            (box-ba (vxy-trunc (n*m view-matrix
+                                    (m* drawable-matrix (vec3 bx ay 1))))))
+        (values (vmin box-a box-b box-ab box-ba)
+                (vmax box-a box-b box-ab box-ba))))))
+
 (defun in-view-p (drawable drawable-matrix view-matrix view-box)
   "Determine if drawable is in the view defined by view-matrix and view-box."
-  (let ((drawable-culling-box (o! drawable culling-box))
-        box-a box-b)
-    (setf box-a (vxy-trunc (m* view-matrix
-                               (m* drawable-matrix (vxy1 (car drawable-culling-box))))))
-    (setf box-b (vxy-trunc (m* view-matrix
-                               (m* drawable-matrix (vxy1 (cdr drawable-culling-box))))))
+  (multiple-value-bind (box-min box-max)
+      (transform-box (o! drawable culling-box) drawable-matrix view-matrix)
     ;; If it's in view at all, either its top-right corner is >= bottom-left of view,
     ;; or its bottom-left is <= top-right of view
-    (or (v>= (vmax box-a box-b) (car view-box))
-        (v<= (vmin box-a box-b) (cdr view-box)))))
+    (or (v>= box-max (car view-box))
+        (v<= box-min (cdr view-box)))))
 
 (defmethod render-drawable ((this view) drawable view-matrix)
   "Render drawable with the precomputed view-matrix."