Move animations into data and function, do slides

data/DrivingCodeWithData.cakedata

@@ -3,4 +3,49 @@
  (array
   (slide-data :heading "Driving code with data" :body "Macoy Madson")
   (slide-data :heading "Setting the stage")
-  (slide-data :heading "Slide 2" :body "More blah")))
+  (slide-data :heading "First pass"
+              :body "if shouldShootFireball():
+{
+    makeFireball();
+}
+
+for each fireball:
+{
+    updateFireballs();
+}")
+  (slide-data :heading "What about ice storms?" :body "if shouldShootFireball():
+{
+    makeFireball();
+}
+else if shouldShootIceStore():
+{
+    makeIceStorm();
+}
+
+for each fireball in fireballs:
+{
+    updateFireball(fireball);
+}
+for each iceStorm in iceStorms:
+{
+    updateIceStorm(iceStorm);
+}")
+  (slide-data :heading "We want" :body "slime sling
+laser blast
+heat seeker
+...")
+  (slide-data :heading "We have a problem")
+  (slide-data :heading "Second pass: sharing code"
+              :body "for each projectile in projectiles:
+{
+    updateProjectile(projectile);
+}")
+  (slide-data :heading "It works, but..."
+              :body "The code is a mess:
+- Special cases everywhere
+- No easy way to add new types or classes of things
+- No clear centralization of functionality
+- Complexity spreads")
+  (slide-data :heading "What are computers good at?")
+  (slide-data :heading "Storing and manipulating data")
+  (slide-data :heading "Describe the behavior in data")))

src/Presentation.cake

@@ -66,6 +66,73 @@
 (bundle-file s-start-boar-spritesheet s-end-boar-spritesheet
              (unsigned char) "/home/macoy/Documents/boar.bmp")
 
+(defstruct-local spritesheet
+  texture (* SDL_Texture)
+  width uint16_t
+  height uint16_t
+  frame-width uint16_t
+  frame-height uint16_t
+  scale-factor (unsigned char))
+
+(defstruct-local animation
+  start-frame-index (unsigned char)
+  end-frame-index (unsigned char)
+  flip SDL_RendererFlip)
+
+(var spritesheet-wizard spritesheet (array null
+                                           966 636
+                                           6 6
+                                           2))
+(var anim-wizard-idle animation (array 0 5 SDL_FLIP_HORIZONTAL))
+
+(var spritesheet-boar spritesheet (array null
+                                         1434 1068
+                                         6 6
+                                         2))
+(var anim-boar-idle animation (array 0 6 SDL_FLIP_HORIZONTAL))
+(var anim-boar-damage animation (array (+ (* 3 6) 3) (+ (* 3 6) 5) SDL_FLIP_HORIZONTAL))
+
+(var c-animation-frame-rate (const float) 0.1f)
+
+(defun-local render-animation (renderer (* SDL_Renderer)
+                               sprite (* spritesheet) anim (* animation)
+                               animation-start-ticks Uint64
+                               frame-rate float
+                               x int y int)
+  (var num-frames int (- (+ 1 (path anim > end-frame-index)) ;; TODO: Off by one?
+                         (path anim > start-frame-index)))
+  (var loop-rate float (* frame-rate num-frames))
+  (var sprite-width int (/ (path sprite > width) (path sprite > frame-width)))
+  (var sprite-height int (/ (path sprite > height) (path sprite > frame-height)))
+
+  (var animation-time-seconds float
+    (/ (- (SDL_GetPerformanceCounter) animation-start-ticks)
+       (type-cast (SDL_GetPerformanceFrequency) float)))
+  (var-cast-to current-frame int
+               (interpolate-range
+                0.f (type-cast num-frames float)
+                0.f loop-rate
+                (- animation-time-seconds
+                   (* loop-rate (truncf (/ animation-time-seconds loop-rate))))))
+  (var frame-x int (mod (+ current-frame (path anim > start-frame-index))
+                        (path sprite > frame-width)))
+  (var frame-y int (/ (+ current-frame (path anim > start-frame-index))
+                      (path sprite > frame-width)))
+
+  (var source-rectangle SDL_Rect
+    (array (* frame-x sprite-width) (* frame-y sprite-height)
+           sprite-width
+           sprite-height))
+  (var destination-rectangle SDL_Rect
+    (array x y
+           (* (path sprite > scale-factor) sprite-width)
+           (* (path sprite > scale-factor) sprite-height)))
+  (unless (= 0 (SDL_RenderCopyEx renderer (path sprite > texture)
+                                 (addr source-rectangle) (addr destination-rectangle)
+                                 0.f null ;; no rotation
+                                 (path anim > flip)))
+    (sdl-print-error)))
+
 ;;
 ;; Text rendering
 ;;
@@ -217,22 +284,21 @@
                                        code-font-size-points)
     (return 1))
 
-  (var wizard-width int 161)
-  (var wizard-height int 106)
   (var wizard-texture (* SDL_Texture)
     (sdl-texture-from-bmp-data renderer s-start-wizard-spritesheet s-end-wizard-spritesheet))
   (unless wizard-texture
     (return 1))
   (defer (SDL_DestroyTexture wizard-texture))
 
-  (var boar-width int 239)
-  (var boar-height int 178)
   (var boar-texture (* SDL_Texture)
     (sdl-texture-from-bmp-data renderer s-start-boar-spritesheet s-end-boar-spritesheet))
   (unless boar-texture
     (return 1))
   (defer (SDL_DestroyTexture boar-texture))
 
+  (set (field spritesheet-wizard texture) wizard-texture)
+  (set (field spritesheet-boar texture) boar-texture)
+
   ;; current-key-states is owned by SDL, but we own last-frame-states
   (defer (dynarray-free (field s-key-states last-frame-states)))
 
@@ -355,50 +421,20 @@
 	;; 	return 1;
 	;; }#"#)
 
-    (var animation-time-seconds float
-      (/ (- (SDL_GetPerformanceCounter) animation-start-ticks)
-         (type-cast (SDL_GetPerformanceFrequency) float)))
-    (var loop-rate float 0.7f)
-    (var num-frames int 6)
-    (var-cast-to current-frame int
-                 (interpolate-range
-                  0.f (type-cast num-frames float)
-                  0.f loop-rate
-                  (- animation-time-seconds
-                     (* loop-rate (truncf (/ animation-time-seconds loop-rate))))))
-    (when (> current-slide-index 0)
-      (var source-rectangle SDL_Rect
-        (array (* current-frame wizard-width) 0
-               wizard-width
-               wizard-height))
-      (var destination-rectangle SDL_Rect
-        (array (type-cast (* window-width 0.08f) int)
-               (type-cast (* window-height 0.77f) int)
-               (* 2 wizard-width)
-               (* 2 wizard-height)))
-      (unless (= 0 (SDL_RenderCopyEx renderer wizard-texture
-                                     (addr source-rectangle) (addr destination-rectangle)
-                                     0.f null ;; no rotation
-                                     SDL_FLIP_HORIZONTAL))
-        (sdl-print-error)
-        (set exit-reason "SDL failed to render wizard")))
-
-    (when (> current-slide-index 0)
-      (var source-rectangle SDL_Rect
-        (array (* current-frame boar-width) 0
-               boar-width
-               boar-height))
-      (var destination-rectangle SDL_Rect
-        (array (type-cast (* window-width 0.70f) int)
-               (type-cast (* window-height 0.63f) int)
-               (* 2 boar-width)
-               (* 2 boar-height)))
-      (unless (= 0 (SDL_RenderCopyEx renderer boar-texture
-                                     (addr source-rectangle) (addr destination-rectangle)
-                                     0.f null ;; no rotation
-                                     SDL_FLIP_HORIZONTAL))
-        (sdl-print-error)
-        (set exit-reason "SDL failed to render boar")))
+    (when (>= current-slide-index 1)
+      (render-animation
+       renderer (addr spritesheet-wizard) (addr anim-wizard-idle)
+       animation-start-ticks c-animation-frame-rate
+       (type-cast (* window-width 0.08f) int)
+       (type-cast (* window-height 0.77f) int))
+
+      (var-static boar-state (* animation) (addr anim-boar-idle))
+      ;; (when (> current-slide-index 1) (set boar-state (addr anim-boar-damage)))
+      (render-animation
+       renderer (addr spritesheet-boar) boar-state
+       animation-start-ticks c-animation-frame-rate
+       (type-cast (* window-width 0.70f) int)
+       (type-cast (* window-height 0.63f) int)))
 
     (SDL_RenderPresent renderer)
     (SDL_UpdateWindowSurface window)