From e98c2e0535b6baf1691cff53996ecfd02121899f Mon Sep 17 00:00:00 2001
From: Jonas Kulla <Nyocurio@gmail.com>
Date: Wed, 27 Jul 2016 11:59:08 +0200
Subject: [PATCH] Bitmap: Don't throw away cached surface in setPixel()
Instead, update the surface with the same change. For many
consecutive getPixel() -> setPixel() calls on the same bitmap,
this avoids calling glReadPixels at every iteration.
---
src/bitmap.cpp | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/src/bitmap.cpp b/src/bitmap.cpp
index b2d1f3d..a677207 100644
--- a/src/bitmap.cpp
+++ b/src/bitmap.cpp
@@ -221,9 +221,9 @@ struct BitmapPrivate
surf = surfConv;
}
- void onModified()
+ void onModified(bool freeSurface = true)
{
- if (surface)
+ if (surface && freeSurface)
{
SDL_FreeSurface(surface);
surface = 0;
@@ -825,7 +825,16 @@ void Bitmap::setPixel(int x, int y, const Color &color)
p->addTaintedArea(IntRect(x, y, 1, 1));
- p->onModified();
+ /* Setting just a single pixel is no reason to throw away the
+ * whole cached surface; we can just apply the same change */
+
+ if (p->surface)
+ {
+ uint32_t &surfPixel = getPixelAt(p->surface, p->format, x, y);
+ surfPixel = SDL_MapRGBA(p->format, pixel[0], pixel[1], pixel[2], pixel[3]);
+ }
+
+ p->onModified(false);
}
void Bitmap::hueChange(int hue)