Built SDL2_image and _mixer static

libsdl2_mixer/effect_stereoreverse.c

@@ -0,0 +1,146 @@
+/*
+  SDL_mixer:  An audio mixer library based on the SDL library
+  Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  This file by Ryan C. Gordon (icculus@icculus.org)
+
+  These are some internally supported special effects that use SDL_mixer's
+  effect callback API. They are meant for speed over quality.  :)
+*/
+
+/* $Id$ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "SDL.h"
+#include "SDL_mixer.h"
+
+#define __MIX_INTERNAL_EFFECT__
+#include "effects_internal.h"
+
+/* profile code:
+    #include <sys/time.h>
+    #include <unistd.h>
+    struct timeval tv1;
+    struct timeval tv2;
+
+    gettimeofday(&tv1, NULL);
+
+        ... do your thing here ...
+
+    gettimeofday(&tv2, NULL);
+    printf("%ld\n", tv2.tv_usec - tv1.tv_usec);
+*/
+
+
+
+/*
+ * Stereo reversal effect...this one's pretty straightforward...
+ */
+
+static void SDLCALL _Eff_reversestereo32(int chan, void *stream, int len, void *udata)
+{
+    /* 16 bits * 2 channels. */
+    Uint32 *ptr = (Uint32 *) stream;
+    Uint32 tmp;
+    int i;
+
+    for (i = 0; i < len; i += 2 * sizeof (Uint32), ptr += 2) {
+        tmp = ptr[0];
+        ptr[0] = ptr[1];
+        ptr[1] = tmp;
+    }
+}
+
+
+static void SDLCALL _Eff_reversestereo16(int chan, void *stream, int len, void *udata)
+{
+    /* 16 bits * 2 channels. */
+    Uint32 *ptr = (Uint32 *) stream;
+    int i;
+
+    for (i = 0; i < len; i += sizeof (Uint32), ptr++) {
+        *ptr = (((*ptr) & 0xFFFF0000) >> 16) | (((*ptr) & 0x0000FFFF) << 16);
+    }
+}
+
+
+static void SDLCALL _Eff_reversestereo8(int chan, void *stream, int len, void *udata)
+{
+    /* 8 bits * 2 channels. */
+    Uint32 *ptr = (Uint32 *) stream;
+    int i;
+
+    /* get the last two bytes if len is not divisible by four... */
+    if (len % sizeof (Uint32) != 0) {
+        Uint16 *p = (Uint16 *) (((Uint8 *) stream) + (len - 2));
+        *p = (Uint16)((((*p) & 0xFF00) >> 8) | (((*ptr) & 0x00FF) << 8));
+        len -= 2;
+    }
+
+    for (i = 0; i < len; i += sizeof (Uint32), ptr++) {
+        *ptr = (((*ptr) & 0x0000FF00) >> 8) | (((*ptr) & 0x000000FF) << 8) |
+               (((*ptr) & 0xFF000000) >> 8) | (((*ptr) & 0x00FF0000) << 8);
+    }
+}
+
+
+int Mix_SetReverseStereo(int channel, int flip)
+{
+    Mix_EffectFunc_t f = NULL;
+    int channels;
+    Uint16 format;
+
+    Mix_QuerySpec(NULL, &format, &channels);
+
+    if (channels == 2) {
+        int bits = (format & 0xFF);
+        switch (bits) {
+        case 8:
+            f = _Eff_reversestereo8;
+            break;
+        case 16:
+            f = _Eff_reversestereo16;
+            break;
+        case 32:
+            f = _Eff_reversestereo32;
+            break;
+        default:
+            Mix_SetError("Unsupported audio format");
+            return(0);
+        }
+
+        if (!flip) {
+            return(Mix_UnregisterEffect(channel, f));
+        } else {
+            return(Mix_RegisterEffect(channel, f, NULL, NULL));
+        }
+    } else {
+        Mix_SetError("Trying to reverse stereo on a non-stereo stream");
+        return(0);
+    }
+
+    return(1);
+}
+
+
+/* end of effect_stereoreverse.c ... */
+
+/* vi: set ts=4 sw=4 expandtab: */