From 92e5d8214d2e59913354898529322f4d4a624bee Mon Sep 17 00:00:00 2001
From: helixhorned <helixhorned@1a8010ca-5511-0410-912e-c29ae57300e0>
Date: Wed, 28 Dec 2011 20:34:57 +0000
Subject: [PATCH] SDL layer: don't call SDL_SetGammaRamp() if there would be no
 change.

This is in the similar vein as the set-palette deferring and it's this
that fixes the low FPS in the radioactively contaminated area in AMC TC:
Megabase (since setgamma() is called from setbrightness()).

Again, update issues might be expected, but changing focus between EDuke32
and the desktop and back seems to restore the gamma settings properly on
Kubuntu. Looks like X (or whatever above handles this stuff) maintains it
on a per-application basis.

git-svn-id: https://svn.eduke32.com/eduke32@2222 1a8010ca-5511-0410-912e-c29ae57300e0
---
 polymer/eduke32/build/src/sdlayer.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/polymer/eduke32/build/src/sdlayer.c b/polymer/eduke32/build/src/sdlayer.c
index 2fec77572..47157e4f6 100644
--- a/polymer/eduke32/build/src/sdlayer.c
+++ b/polymer/eduke32/build/src/sdlayer.c
@@ -11,7 +11,7 @@
 #include "compat.h"
 #include "sdlayer.h"
 #include "cache1d.h"
-#include "pragmas.h"
+//#include "pragmas.h"
 #include "a.h"
 #include "build.h"
 #include "osd.h"
@@ -77,6 +77,9 @@ char nogl=0;
 #endif
 int32_t vsync=0;
 
+// last gamma, contrast, brightness
+static float lastvidgcb[3];
+
 //#define KEY_PRINT_DEBUG
 
 #if (SDL_MAJOR_VERSION == 1 && SDL_MINOR_VERSION < 3)
@@ -998,6 +1001,9 @@ int32_t setvideomode(int32_t x, int32_t y, int32_t c, int32_t fs)
     if (bpp > 8 && sdl_surface) polymost_glreset();
 #endif
 
+    // clear last gamma/contrast/brightness so that it will be set anew
+    lastvidgcb[0] = lastvidgcb[1] = lastvidgcb[2] = 0.0f;
+
     // restore gamma before we change video modes if it was changed
     if (sdl_surface && gammabrightness)
     {
@@ -1524,6 +1530,9 @@ int32_t setgamma(void)
 
     if (novideo) return 0;
 
+    if (lastvidgcb[0]==gamma && lastvidgcb[1]==contrast && lastvidgcb[2]==bright)
+        return 0;
+
     // This formula is taken from Doomsday
 
     for (i = 0; i < 256; i++)
@@ -1534,7 +1543,17 @@ int32_t setgamma(void)
 
         gammaTable[i] = gammaTable[i + 256] = gammaTable[i + 512] = (uint16_t)max(0.f,(double)min(0xffff,val*256));
     }
-    return SDL_SetGammaRamp(&gammaTable[0],&gammaTable[256],&gammaTable[512]);
+
+    i = SDL_SetGammaRamp(&gammaTable[0],&gammaTable[256],&gammaTable[512]);
+
+    if (i != -1)
+    {
+        lastvidgcb[0] = gamma;
+        lastvidgcb[1] = contrast;
+        lastvidgcb[2] = bright;
+    }
+
+    return i;
 }
 
 #ifndef __APPLE__