Ported helpful functions from Kitty-Gridlock

This is a good way to grow GameLib - by only bringing things in which
have proved useful on previous projects.

src/Math.cake

@@ -79,6 +79,43 @@
 (defun vec3-scale-add-vec3 (vec-to-scale vec3 scale float vec-to-add vec3 &return vec3)
   (return (vec3-add vec-to-add (vec3-scale vec-to-scale scale))))
 
+;; Factor 0 to 1
+(defun vec2-interpolate (factor float from vec2 to vec2 &return vec2)
+  (return (array
+           (interpolate-range (vec-x from) (vec-x to)
+                              0.f 1.f factor)
+           (interpolate-range (vec-y from) (vec-y to)
+                              0.f 1.f factor))))
+
+;; Factor 0 to 1
+(defun vec3-interpolate (factor float from vec3 to vec3 &return vec3)
+  (return
+    (array
+     (interpolate-range (vec-x from) (vec-x to)
+                        0.f 1.f factor)
+     (interpolate-range (vec-y from) (vec-y to)
+                        0.f 1.f factor)
+     (interpolate-range (vec-z from) (vec-z to)
+                        0.f 1.f factor))))
+
+(defun vec2-is-zero (vec vec2 &return bool)
+  (return (and (= 0.f (vec-x vec))
+               (= 0.f (vec-y vec)))))
+
+(defun vec3-is-zero (vec vec3 &return bool)
+  (return (and (= 0.f (vec-x vec))
+               (= 0.f (vec-y vec))
+               (= 0.f (vec-z vec)))))
+
+(defun vec2-is-within-aabb (point-to-test vec2 upper-left vec2 size vec2 &return bool)
+  (var bottom-right vec2 (vec2-add upper-left size))
+  (return
+    (and
+     (>= (vec-x point-to-test) (vec-x upper-left))
+     (>= (vec-y point-to-test) (vec-y upper-left))
+     (< (vec-x point-to-test) (vec-x bottom-right))
+     (< (vec-y point-to-test) (vec-y bottom-right)))))
+
 ;; Expand vector to each of its components
 ;; TODO: Change to any, prevent multiple eval?
 (defmacro vec-xy (vec symbol)

src/SDL.cake

@@ -7,6 +7,10 @@
           "SDL.h"
           "SDL_syswm.h")
 
+;;
+;; Core/windowing
+;;
+
 (forward-declare (struct SDL_Window)
                  (struct SDL_AudioSpec))
 
@@ -66,6 +70,65 @@
   (SDL_DestroyWindow window)
   (SDL_Quit))
 
+;;
+;; Graphics
+;;
+(defun sdl-list-2d-render-drivers (&return bool)
+  (var num-render-drivers int (SDL_GetNumRenderDrivers))
+  (unless num-render-drivers
+    (return false))
+  (var i int 0)
+  (each-in-range
+      num-render-drivers i
+    (var driver-info SDL_RendererInfo (array 0))
+    (unless (= 0 (SDL_GetRenderDriverInfo i (addr driver-info)))
+      (return false))
+    (SDL_Log "Renderer [%d]: %s\n
+\tHardware accelerated: %s\n
+\tRender to texture:    %s\n
+\tMax texture width:    %d\n
+\tMax texture height:   %d\n
+\n"
+             i (field driver-info name)
+             (? (bit-and (field driver-info flags) SDL_RENDERER_ACCELERATED) "yes" "no")
+             (? (bit-and (field driver-info flags) SDL_RENDERER_TARGETTEXTURE) "yes" "no")
+             (field driver-info max_texture_width)
+             (field driver-info max_texture_height)))
+  (return true))
+
+(defun-local sdl-texture-from-bmp (filename (* (const char)) renderer (* SDL_Renderer)
+                                            &return (* SDL_Texture))
+  (var surface (* SDL_Surface) (SDL_LoadBMP filename))
+  (unless surface
+    (SDL_Log "Failed to load surface from BMP %s\n" filename)
+    (sdl-print-error)
+    (return null))
+
+  (var texture (* SDL_Texture)
+       (SDL_CreateTextureFromSurface renderer surface))
+  ;; No need to hold on to surface after texture has been created
+  (SDL_FreeSurface surface)
+  (unless texture (sdl-print-error))
+  (return texture))
+
+(defun-local sdl-texture-from-bmp-color-to-transparent
+    (filename (* (const char)) renderer (* SDL_Renderer) r char g char b char
+              &return (* SDL_Texture))
+  (var surface (* SDL_Surface) (SDL_LoadBMP filename))
+  (unless surface
+    (SDL_Log "Failed to load surface from BMP %s\n" filename)
+    (sdl-print-error)
+    (return null))
+
+  (SDL_SetColorKey surface SDL_TRUE (SDL_MapRGB (path surface > format) r g b))
+
+  (var texture (* SDL_Texture)
+       (SDL_CreateTextureFromSurface renderer surface))
+  ;; No need to hold on to surface after texture has been created
+  (SDL_FreeSurface surface)
+  (unless texture (sdl-print-error))
+  (return texture))
+
 ;;
 ;; Audio
 ;;
@@ -101,6 +164,24 @@
     (incr i))
   (free device-names))
 
+;;
+;; Time
+;;
+
+;; Useful for getting a quick idea how long something takes, e.g.:
+;; (var start-load-ticks (const Uint64) (SDL_GetPerformanceFrequency))
+;; (do-load)
+;; (sdl-print-time-delta start-load-ticks "Loading done")
+;; ...Will print e.g. "--- Loading done at 0.94 seconds"
+(defun-local sdl-print-time-delta (start-num-perf-ticks Uint64 label (* (const char)))
+  (var performance-num-ticks-per-second (const Uint64) (SDL_GetPerformanceFrequency))
+
+  (var current-counter-ticks Uint64 (SDL_GetPerformanceCounter))
+  (var frame-diff-ticks Uint64 (- current-counter-ticks start-num-perf-ticks))
+  (var delta-time float (/ frame-diff-ticks
+                           (type-cast performance-num-ticks-per-second float)))
+
+  (SDL_Log "---  %s at %f seconds\n" label delta-time))
 
 ;;
 ;; Test