render: sprite: Improve argument names to draw-sprite.

1 files changed, 59 insertions, 51 deletions

diff --git a/chickadee/render/sprite.scm b/chickadee/render/sprite.scm
index 8dabd07..2288edf 100644
--- a/chickadee/render/sprite.scm
+++ b/chickadee/render/sprite.scm
@@ -72,12 +72,12 @@ void main (void) {
          (tmp-matrix (make-null-matrix4))
          (mvp (make-null-matrix4))
          (position (vec2 0 0)))
-    (lambda (texture dimensions scale rotation blend-mode shader texture-rect)
+    (lambda (texture region scale rotation blend-mode shader texture-region)
       (with-mapped-vertex-buffer (force vertex-buffer)
         (let* ((x1 0)
                (y1 0)
-               (x2 (rect-width dimensions))
-               (y2 (rect-height dimensions))
+               (x2 (rect-width region))
+               (y2 (rect-height region))
                (bv (vertex-buffer-data (force vertex-buffer))))
           (f32vector-set! bv 0 x1)
           (f32vector-set! bv 1 y1)
@@ -88,10 +88,10 @@ void main (void) {
           (f32vector-set! bv 6 x1)
           (f32vector-set! bv 7 y2)))
       (with-mapped-vertex-buffer (force texcoord-buffer)
-        (let ((s1 (rect-left texture-rect))
-              (t1 (rect-bottom texture-rect))
-              (s2 (rect-right texture-rect))
-              (t2 (rect-top texture-rect))
+        (let ((s1 (rect-left texture-region))
+              (t1 (rect-bottom texture-region))
+              (s2 (rect-right texture-region))
+              (t2 (rect-top texture-region))
               (bv (vertex-buffer-data (force texcoord-buffer))))
           (f32vector-set! bv 0 s1)
           (f32vector-set! bv 1 t1)
@@ -108,8 +108,8 @@ void main (void) {
       (when scale
         (matrix4-scale! tmp-matrix scale)
         (matrix4-mult! mvp mvp tmp-matrix))
-      (set-vec2-x! position (rect-x dimensions))
-      (set-vec2-y! position (rect-y dimensions))
+      (set-vec2-x! position (rect-x region))
+      (set-vec2-y! position (rect-y region))
       (matrix4-translate! tmp-matrix position)
       (matrix4-mult! mvp mvp tmp-matrix)
       (matrix4-mult! mvp mvp (current-projection))
@@ -213,8 +213,8 @@ void main (void) {
       (u32vector-set! offset-bv 0 offset))
     (define (offset)
       (u32vector-ref offset-bv 0))
-    (lambda (batch texture dimensions scale rotation blend-mode
-                   shader texture-rect)
+    (lambda (batch texture region scale rotation blend-mode
+                   shader texture-region)
       ;; Expand the buffers when necessary.
       (when (sprite-batch-full? batch)
         (double-sprite-batch-size! batch))
@@ -237,12 +237,12 @@ void main (void) {
                (texcoords (vertex-buffer-data (sprite-batch-texture-buffer batch)))
                (local-x1 0.0)
                (local-y1 0.0)
-               (local-x2 (rect-width dimensions))
-               (local-y2 (rect-height dimensions))
-               (s1 (rect-left texture-rect))
-               (t1 (rect-bottom texture-rect))
-               (s2 (rect-right texture-rect))
-               (t2 (rect-top texture-rect)))
+               (local-x2 (rect-width region))
+               (local-y2 (rect-height region))
+               (s1 (rect-left texture-region))
+               (t1 (rect-bottom texture-region))
+               (s2 (rect-right texture-region))
+               (t2 (rect-top texture-region)))
           (matrix4-identity! matrix)
           (when rotation
             (matrix4-rotate-z! tmp-matrix rotation)
@@ -250,8 +250,8 @@ void main (void) {
           (when scale
             (matrix4-scale! tmp-matrix scale)
             (matrix4-mult! matrix matrix tmp-matrix))
-          (set-vec2-x! position (rect-x dimensions))
-          (set-vec2-y! position (rect-y dimensions))
+          (set-vec2-x! position (rect-x region))
+          (set-vec2-y! position (rect-y region))
           (matrix4-translate! tmp-matrix position)
           (matrix4-mult! matrix matrix tmp-matrix)
           (set-vec2-x! world1 local-x1)
@@ -307,14 +307,15 @@ void main (void) {
 (define *batch?* #f)
 (define %batch (delay (make-sprite-batch 256)))
 
-(define (draw-sprite-batched texture dimensions
+(define (draw-sprite-batched texture region
                              scale rotation blend-mode shader
-                             texture-rect)
-  (sprite-batch-add! (force %batch) texture dimensions
+                             texture-region)
+  (sprite-batch-add! (force %batch) texture region
                      scale rotation blend-mode shader
-                     texture-rect))
+                     texture-region))
 
 (define-syntax-rule (with-batched-sprites body ...)
+  "Use batched rendering for all draw-sprite calls within BODY."
   (if *batch?*
       (begin body ...)
       (dynamic-wind
@@ -327,29 +328,36 @@ void main (void) {
         (lambda ()
           (set! *batch?* #f)))))
 
-(define %default-texture-rect (make-rect 0.0 0.0 1.0 1.0))
+(define %default-texture-region (make-rect 0.0 0.0 1.0 1.0))
 
 (define draw-sprite
   (let ((rect (make-rect 0.0 0.0 0.0 0.0)))
-    (lambda* (texture dimensions #:key
+    (lambda* (texture region #:key
                       scale rotation (blend-mode 'alpha)
-                      texture-rect
+                      texture-region
                       (shader (force default-shader)))
-      (let ((dimensions (if (vec2? dimensions)
-                            (begin
-                              (rect-move-vec2! rect dimensions)
-                              (set-rect-width! rect (texture-width texture))
-                              (set-rect-height! rect (texture-height texture))
-                              rect)
-                            dimensions))
-            (texture-rect (or texture-rect %default-texture-rect)))
+      "Draw TEXTURE over the area defined by the rect REGION.  If
+TEXTURE-REGION is specified, the subset of the texture defined by it
+will be drawn rather than the entire texture.  ROTATION specifies by
+how many radians the sprite will be rotated.  SCALE specifies the
+scaling factor.  By default, alpha blending is used but can be changed
+by setting BLEND-MODE.  Finally, advanced users may pass SHADER to
+change the way the sprite is rendered entirely."
+      (let ((region (if (vec2? region)
+                        (begin
+                          (rect-move-vec2! rect region)
+                          (set-rect-width! rect (texture-width texture))
+                          (set-rect-height! rect (texture-height texture))
+                          rect)
+                        region))
+            (texture-region (or texture-region %default-texture-region)))
         (if *batch?*
-            (draw-sprite-batched texture dimensions
+            (draw-sprite-batched texture region
                                  scale rotation blend-mode shader
-                                 texture-rect)
-            (draw-sprite-unbatched texture dimensions
+                                 texture-region)
+            (draw-sprite-unbatched texture region
                                    scale rotation blend-mode shader
-                                   texture-rect))))))
+                                   texture-region))))))
 
 
 ;;;
@@ -359,10 +367,10 @@ void main (void) {
 (define draw-nine-patch
   (let ((rect (make-rect 0.0 0.0 0.0 0.0))
         (trect (make-rect 0.0 0.0 0.0 0.0)))
-    (lambda* (texture dimensions #:key (margin 0)
+    (lambda* (texture region #:key (margin 0)
                       (top-margin margin) (bottom-margin margin)
                       (left-margin margin) (right-margin margin)
-                      (texture-rect %default-texture-rect)
+                      (texture-region %default-texture-region)
                       scale rotation (blend-mode 'alpha)
                       (shader (force default-shader)))
       "Draw a \"nine patch\" sprite.  A nine patch sprite renders
@@ -377,22 +385,22 @@ graphical user interfaces.
 MARGIN specifies the margin size for all sides of the nine patch.  To
 make margins of differing sizes, the TOP-MARGIN, BOTTOM-MARGIN,
 LEFT-MARGIN, and RIGHT-MARGIN arguments may be used."
-      (let* ((w (rect-width dimensions))
-             (h (rect-height dimensions))
-             (border-x1 (rect-left dimensions))
-             (border-y1 (rect-bottom dimensions))
-             (border-x2 (rect-right dimensions))
-             (border-y2 (rect-top dimensions))
+      (let* ((w (rect-width region))
+             (h (rect-height region))
+             (border-x1 (rect-left region))
+             (border-y1 (rect-bottom region))
+             (border-x2 (rect-right region))
+             (border-y2 (rect-top region))
              (fill-x1 (+ border-x1 left-margin))
              (fill-y1 (+ border-y1 bottom-margin))
              (fill-x2 (- border-x2 right-margin))
              (fill-y2 (- border-y2 top-margin))
              (tw (texture-width texture))
              (th (texture-width texture))
-             (border-s1 (rect-left texture-rect))
-             (border-t1 (rect-bottom texture-rect))
-             (border-s2 (rect-right texture-rect))
-             (border-t2 (rect-top texture-rect))
+             (border-s1 (rect-left texture-region))
+             (border-t1 (rect-bottom texture-region))
+             (border-s2 (rect-right texture-region))
+             (border-t2 (rect-top texture-region))
              (fill-s1 (+ border-s1 (/ left-margin tw)))
              (fill-t1 (+ border-t1 (/ bottom-margin th)))
              (fill-s2 (- border-s2 (/ right-margin tw)))
@@ -407,7 +415,7 @@ LEFT-MARGIN, and RIGHT-MARGIN arguments may be used."
           (set-rect-width! trect (- s2 s1))
           (set-rect-height! trect (- t2 t1))
           (draw-sprite texture rect
-                       #:texture-rect trect
+                       #:texture-region trect
                        #:scale scale
                        #:rotation rotation
                        #:blend-mode blend-mode