From: notaz <notasas@gmail.com>
Date: Wed, 8 Aug 2007 20:57:35 +0000 (+0000)
Subject: A_SN's curve
X-Git-Tag: v1.85~696
X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=82bc9cdd10371209663e62f5a21ab0bccd671ab0;p=picodrive.git

A_SN's curve

git-svn-id: file:///home/notaz/opt/svn/PicoDrive@220 be3aeb3a-fb24-0410-a615-afba39da0efa
---

diff --git a/platform/gp2x/cpuctrl.c b/platform/gp2x/cpuctrl.c
index 9940fd5d..b5b47360 100644
--- a/platform/gp2x/cpuctrl.c
+++ b/platform/gp2x/cpuctrl.c
@@ -255,25 +255,46 @@ void set_RAM_Timings(int tRC, int tRAS, int tWR, int tMRD, int tRFC, int tRP, in
 }
 
 
-void set_gamma(int g100)
+void set_gamma(int g100, int A_SNs_curve)
 {
 	float gamma = (float) g100 / 100;
 	int i;
-	//printf ("set gamma = %f\r\n",gamma);
 	gamma = 1/gamma;
 
-    //enable gamma
-    MEM_REG[0x2880>>1]&=~(1<<12);
+	//enable gamma
+	MEM_REG[0x2880>>1]&=~(1<<12);
 
-    MEM_REG[0x295C>>1]=0;
-    for(i=0; i<256; i++)
-    {
+	MEM_REG[0x295C>>1]=0;
+	for(i=0; i<256; i++)
+	{
 		unsigned char g;
-        unsigned short s;
-        g =(unsigned char)(255.0*pow(i/255.0,gamma));
-        s = (g<<8) | g;
+		unsigned short s;
+		const unsigned short grey50=143, grey75=177, grey25=97;
+		float blah;
+
+		if (A_SNs_curve)
+		{
+			// The next formula is all about gaussian interpolation
+			blah = ((  -128 * exp(-powf((float) i/64.0f + 2.0f , 2.0f))) +
+				(   -64 * exp(-powf((float) i/64.0f + 1.0f , 2.0f))) +
+				(grey25 * exp(-powf((float) i/64.0f - 1.0f , 2.0f))) +
+				(grey50 * exp(-powf((float) i/64.0f - 2.0f , 2.0f))) +
+				(grey75 * exp(-powf((float) i/64.0f - 3.0f , 2.0f))) +
+				(   256 * exp(-powf((float) i/64.0f - 4.0f , 2.0f))) +
+				(   320 * exp(-powf((float) i/64.0f - 5.0f , 2.0f))) +
+				(   384 * exp(-powf((float) i/64.0f - 6.0f , 2.0f)))) / (1.772637f);
+			blah += 0.5f;
+		}
+		else
+		{
+			blah = i;
+		}
+
+		g = (unsigned char)(255.0*pow(blah/255.0,gamma));
+		//printf("%d : %d\n", i, g);
+		s = (g<<8) | g;
 		MEM_REG[0x295E>>1]= s;
-        MEM_REG[0x295E>>1]= g;
-    }
+		MEM_REG[0x295E>>1]= g;
+	}
 }
 
diff --git a/platform/gp2x/cpuctrl.h b/platform/gp2x/cpuctrl.h
index eb2dc0a2..b9b23283 100644
--- a/platform/gp2x/cpuctrl.h
+++ b/platform/gp2x/cpuctrl.h
@@ -11,7 +11,7 @@ extern void set_DCLK_Div(unsigned short div); /* 0 to 7 divider (freq=FCLK/(1+di
 //extern void Disable_940(void); /* 940t down */
 
 extern void set_RAM_Timings(int tRC, int tRAS, int tWR, int tMRD, int tRFC, int tRP, int tRCD);
-extern void set_gamma(int g100);
+extern void set_gamma(int g100, int A_SNs_curve);
 
 typedef enum
 {
diff --git a/platform/gp2x/emu.c b/platform/gp2x/emu.c
index 36d956a4..0e1246ce 100644
--- a/platform/gp2x/emu.c
+++ b/platform/gp2x/emu.c
@@ -613,7 +613,7 @@ void emu_Deinit(void)
 
 	// restore gamma
 	if (gp2x_old_gamma != 100)
-		set_gamma(100);
+		set_gamma(100, 0);
 }
 
 
@@ -1079,10 +1079,10 @@ void emu_Loop(void)
 		printf(" done\n");
 	}
 
-	if (gp2x_old_gamma != currentConfig.gamma) {
-		set_gamma(currentConfig.gamma);
+	if (gp2x_old_gamma != currentConfig.gamma || (EmuOpt_old&0x1000) != (currentConfig.EmuOpt&0x1000)) {
+		set_gamma(currentConfig.gamma, !!(currentConfig.EmuOpt&0x1000));
 		gp2x_old_gamma = currentConfig.gamma;
-		printf("updated gamma to %i\n", currentConfig.gamma);
+		printf("updated gamma to %i, A_SN's curve: %i\n", currentConfig.gamma, !!(currentConfig.EmuOpt&0x1000));
 	}
 
 	if ((EmuOpt_old&0x2000) != (currentConfig.EmuOpt&0x2000)) {
diff --git a/platform/linux/gp2x.c b/platform/linux/gp2x.c
index c8c95645..ec8b10e1 100644
--- a/platform/linux/gp2x.c
+++ b/platform/linux/gp2x.c
@@ -381,7 +381,7 @@ void set_RAM_Timings(int tRC, int tRAS, int tWR, int tMRD, int tRFC, int tRP, in
 {
 }
 
-void set_gamma(int g100)
+void set_gamma(int g100, int A_SNs_curve)
 {
 }