Created a common filters.hpp file, and began moving function prototypes there.

some function prototypes are still spread between:
    src/gtk/filters.cpp
    src/sdl/filters.cpp
    src/wx/filters.h
They should all be moved to:
    src/filters/filters.hpp

src/filters/filters.hpp

@@ -0,0 +1,67 @@
+/// All filters
+#ifndef FILTERS_FILTERS_HPP
+#define FILTERS_FILTERS_HPP
+
+#include "interframe.hpp"
+
+//pixel.cpp
+void Pixelate(u8 *srcPtr, u32 srcPitch, u8 *deltaPtr, u8 *dstPtr, u32 dstPitch, int width, int height);
+void Pixelate32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */, u8 *dstPtr, u32 dstPitch, int width, int height);
+
+//scanline.cpp
+void Scanlines (u8 *srcPtr, u32 srcPitch, u8 *, u8 *dstPtr, u32 dstPitch, int width, int height);
+void Scanlines32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */, u8 *dstPtr, u32 dstPitch, int width, int height);
+// "TV" here means each pixel is faded horizontally & vertically rather than
+// inserting black scanlines
+// this depends on RGB_LOW_BITS_MASK (included from interframe.hpp
+//extern int RGB_LOW_BITS_MASK;
+void ScanlinesTV(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */, u8 *dstPtr, u32 dstPitch, int width, int height);
+void ScanlinesTV32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */, u8 *dstPtr, u32 dstPitch, int width, int height);
+
+//simpleFilter.cpp
+// the simple ones could greatly benefit from correct usage of preprocessor..
+// in any case, they are worthless, since all renderers do "simple" or
+// better by default
+void Simple2x16(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+              u8 *dstPtr, u32 dstPitch, int width, int height);
+void Simple2x32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+                u8 *dstPtr, u32 dstPitch, int width, int height);
+void Simple3x16(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+              u8 *dstPtr, u32 dstPitch, int width, int height);
+void Simple3x32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+                u8 *dstPtr, u32 dstPitch, int width, int height);
+void Simple4x16(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+              u8 *dstPtr, u32 dstPitch, int width, int height);
+void Simple4x32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+                u8 *dstPtr, u32 dstPitch, int width, int height);
+
+//bilinear.cpp
+//These convert to rgb24 in internal buffers first, and then back again
+/*static void fill_rgb_row_16(u16 *from, int src_width, u8 *row, int width);
+static void fill_rgb_row_32(u32 *from, int src_width, u8 *row, int width);*/
+void Bilinear(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+              u8 *dstPtr, u32 dstPitch, int width, int height);
+void Bilinear32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+                u8 *dstPtr, u32 dstPitch, int width, int height);
+void BilinearPlus(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+                  u8 *dstPtr, u32 dstPitch, int width, int height);
+void BilinearPlus32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+                    u8 *dstPtr, u32 dstPitch, int width, int height);
+
+//hq2x.cpp
+//These require calling hq2x_init first and whenever bpp changes
+/*static void hq2x_16_def(u16* dst0, u16* dst1, const u16* src0, const u16* src1, const u16* src2, unsigned count);
+static void hq2x_32_def(u32* dst0, u32* dst1, const u32* src0, const u32* src1, const u32* src2, unsigned count);
+static void lq2x_16_def(u16* dst0, u16* dst1, const u16* src0, const u16* src1, const u16* src2, unsigned count);
+static void lq2x_32_def(u32* dst0, u32* dst1, const u32* src0, const u32* src1, const u32* src2, unsigned count);*/
+void hq2x_init(unsigned bits_per_pixel);
+void hq2x(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+          u8 *dstPtr, u32 dstPitch, int width, int height);
+void hq2x32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+            u8 *dstPtr, u32 dstPitch, int width, int height);
+void lq2x(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+          u8 *dstPtr, u32 dstPitch, int width, int height);
+void lq2x32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+            u8 *dstPtr, u32 dstPitch, int width, int height);
+
+#endif //FILTERS_FILTERS_HPP

src/gtk/filters.cpp

@@ -18,7 +18,7 @@
 
 #include "filters.h"
 #include "intl.h"
-#include "../filters/interframe.hpp"
+#include "../filters/filters.hpp"
 
 void _2xSaI        (u8 *, u32, u8 *, u8 *, u32, int, int);
 void _2xSaI32      (u8 *, u32, u8 *, u8 *, u32, int, int);
@@ -26,18 +26,8 @@ void Super2xSaI    (u8 *, u32, u8 *, u8 *, u32, int, int);
 void Super2xSaI32  (u8 *, u32, u8 *, u8 *, u32, int, int);
 void SuperEagle    (u8 *, u32, u8 *, u8 *, u32, int, int);
 void SuperEagle32  (u8 *, u32, u8 *, u8 *, u32, int, int);
-void Pixelate      (u8 *, u32, u8 *, u8 *, u32, int, int);
-void Pixelate32    (u8 *, u32, u8 *, u8 *, u32, int, int);
 void AdMame2x      (u8 *, u32, u8 *, u8 *, u32, int, int);
 void AdMame2x32    (u8 *, u32, u8 *, u8 *, u32, int, int);
-void Bilinear      (u8 *, u32, u8 *, u8 *, u32, int, int);
-void Bilinear32    (u8 *, u32, u8 *, u8 *, u32, int, int);
-void BilinearPlus  (u8 *, u32, u8 *, u8 *, u32, int, int);
-void BilinearPlus32(u8 *, u32, u8 *, u8 *, u32, int, int);
-void Scanlines     (u8 *, u32, u8 *, u8 *, u32, int, int);
-void Scanlines32   (u8 *, u32, u8 *, u8 *, u32, int, int);
-void ScanlinesTV   (u8 *, u32, u8 *, u8 *, u32, int, int);
-void ScanlinesTV32 (u8 *, u32, u8 *, u8 *, u32, int, int);
 void hq2x          (u8 *, u32, u8 *, u8 *, u32, int, int);
 void hq2x32        (u8 *, u32, u8 *, u8 *, u32, int, int);
 void lq2x          (u8 *, u32, u8 *, u8 *, u32, int, int);

src/sdl/filters.cpp

@@ -18,7 +18,7 @@
 
 #include "filters.h"
 
-#include "../filters/interframe.hpp"
+#include "../filters/filters.hpp"
 
       //
       // Screen filters
@@ -38,22 +38,8 @@ extern void Super2xSaI(u8*,u32,u8*,u8*,u32,int,int);
 extern void Super2xSaI32(u8*,u32,u8*,u8*,u32,int,int);
 extern void SuperEagle(u8*,u32,u8*,u8*,u32,int,int);
 extern void SuperEagle32(u8*,u32,u8*,u8*,u32,int,int);
-extern void Pixelate(u8*,u32,u8*,u8*,u32,int,int);
-extern void Pixelate32(u8*,u32,u8*,u8*,u32,int,int);
 extern void AdMame2x(u8*,u32,u8*,u8*,u32,int,int);
 extern void AdMame2x32(u8*,u32,u8*,u8*,u32,int,int);
-extern void Bilinear(u8*,u32,u8*,u8*,u32,int,int);
-extern void Bilinear32(u8*,u32,u8*,u8*,u32,int,int);
-extern void BilinearPlus(u8*,u32,u8*,u8*,u32,int,int);
-extern void BilinearPlus32(u8*,u32,u8*,u8*,u32,int,int);
-extern void Scanlines(u8*,u32,u8*,u8*,u32,int,int);
-extern void Scanlines32(u8*,u32,u8*,u8*,u32,int,int);
-extern void ScanlinesTV(u8*,u32,u8*,u8*,u32,int,int);
-extern void ScanlinesTV32(u8*,u32,u8*,u8*,u32,int,int);
-extern void hq2x(u8*,u32,u8*,u8*,u32,int,int);
-extern void hq2x32(u8*,u32,u8*,u8*,u32,int,int);
-extern void lq2x(u8*,u32,u8*,u8*,u32,int,int);
-extern void lq2x32(u8*,u32,u8*,u8*,u32,int,int);
 extern void hq3x16(u8*,u32,u8*,u8*,u32,int,int);
 extern void hq4x16(u8*,u32,u8*,u8*,u32,int,int);
 extern void hq3x32_32(u8*,u32,u8*,u8*,u32,int,int);

src/wx/filters.h

@@ -7,11 +7,8 @@
 // those that take delta take 1 src line of pixels, rounded up to u32 size
 // initial value appears to be all-0xff
 
-#include "../filters/interframe.hpp"
+#include "../filters/filters.hpp"
 
-
-void Pixelate32(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void Pixelate(u8 *src, u32 spitch, u8 *delta, u8 *dst, u32 dstp, int w, int h);
 // next 3*2 use Init_2xSaI(555|565) and do not take into account
 int Init_2xSaI(u32 BitFormat);
 // endianness or bit shift variables in init.
@@ -25,34 +22,7 @@ void SuperEagle32(u8 *src, u32 spitch, u8 *delta, u8 *dst, u32 dstp, int w, int
 void SuperEagle(u8 *src, u32 spitch, u8 *delta, u8 *dst, u32 dstp, int w, int h);
 void AdMame2x32(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
 void AdMame2x(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-// next 4 convert to rgb24 in internal buffers first, and then back again
+
-void Bilinear32(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void Bilinear(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void BilinearPlus32(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void BilinearPlus(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void Scanlines32(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void Scanlines(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void ScanlinesTV32(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-// "TV" here means each pixel is faded horizontally & vertically rather than
-// inserting black scanlines
-// this depends on RGB_LOW_BITS_MASK
-extern int RGB_LOW_BITS_MASK;
-void ScanlinesTV(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-// next 2 require calling hq2x_init first and whenever bpp changes
-void hq2x_init(unsigned bpp);
-void hq2x32(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void hq2x(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void lq2x32(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void lq2x(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-// the simple ones could greatly benefit from correct usage of preprocessor..
-// in any case, they are worthless, since all renderers do "simple" or
-// better by default
-void Simple2x32(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void Simple2x(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void Simple3x32(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void Simple3x(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void Simple4x32(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
-void Simple4x(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
 // note: 16-bit input for asm version only!
 void hq3x32(u8 *src, u32 spitch, u8 *, u8 *dst, u32 dstp, int w, int h);
 // this takes 32-bit input