Optimise cpu particle property upload to minimal set.

Shirakumo · Oct 5, 2023 · db94bea · db94bea
1 parent 6cb9475
commit db94bea
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Showing 2 changed files with 15 additions and 4 deletions.
diff --git a/renderer/cpu-particle.lisp b/renderer/cpu-particle.lisp
@@ -248,19 +248,27 @@
   (when orientation (setf (orientation emitter) orientation))
   (when vertex-array (setf (vertex-array emitter) vertex-array))
   (with-all-slots-bound (emitter cpu-particle-emitter)
-    (let ((mat (tmat (tf emitter))))
+    (let ((mat (tmat (tf emitter)))
+          (min-prop most-positive-fixnum)
+          (max-prop 0))
       (declare (dynamic-extent mat))
       (dotimes (i (min count (length free-list)))
         (let ((pos (* 8 live-particles))
               (prop (vector-pop free-list)))
+          (when (< prop min-prop) (setf min-prop prop))
+          (when (< max-prop prop) (setf max-prop prop))
           (%emit-particle particles properties pos prop (vrand (vec 0.5 0.5 0.5))
                           particle-randomness particle-lifespan-randomness mat
                           particle-velocity particle-rotation particle-lifespan
                           particle-size particle-scaling particle-full-color
                           vertex-data vertex-stride index-data)
-          (incf live-particles))))
-    (when (< 0 live-particles)
-      (update-buffer-data particle-property-buffer T :width (* live-particles (/ 24 4))))))
+          (incf live-particles)))
+      (when (< 0 live-particles)
+        (let ((src (first (sources particle-property-buffer))))
+          (setf (nth 0 (texture-source-src src)) (truncate min-prop 4))
+          (setf (nth 3 (texture-source-dst src)) (truncate (- (+ 24 max-prop) min-prop) 4))
+          (activate particle-property-buffer)
+          (upload-texture-source src particle-property-buffer))))))
 
 (defmethod clear ((emitter cpu-particle-emitter))
   (setf (live-particles emitter) 0)

diff --git a/resources/texture.lisp b/resources/texture.lisp
@@ -278,6 +278,9 @@
       (%gl:get-tex-image (target source) level format type (memory-region-pointer region))
       (apply #'save-image region target type :width (width source) :height (height source) :pixel-type type :pixel-format format args))))
 
+(defmethod activate ((source texture))
+  (gl:bind-texture (target source) (gl-name source)))
+
 ;;;; Texture spec wrangling
 ;; The idea of this is that, in order to maximise sharing of texture resources
 ;; between independent parts, we need to join (in the lattice sense) two texture