Built SDL2_image and _mixer static

libsdl2_mixer/effects_internal.c

@@ -0,0 +1,125 @@
+/*
+  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 helper functions for the internal mixer special effects.
+*/
+
+/* $Id$ */
+
+
+     /* ------ These are used internally only. Don't touch. ------ */
+
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "SDL_mixer.h"
+
+#define __MIX_INTERNAL_EFFECT__
+#include "effects_internal.h"
+
+/* Should we favor speed over memory usage and/or quality of output? */
+int _Mix_effects_max_speed = 0;
+
+
+void _Mix_InitEffects(void)
+{
+    _Mix_effects_max_speed = (SDL_getenv(MIX_EFFECTSMAXSPEED) != NULL);
+}
+
+void _Mix_DeinitEffects(void)
+{
+    _Eff_PositionDeinit();
+}
+
+
+void *_Eff_volume_table = NULL;
+
+
+/* Build the volume table for Uint8-format samples.
+ *
+ * Each column of the table is a possible sample, while each row of the
+ *  table is a volume. Volume is a Uint8, where 0 is silence and 255 is full
+ *  volume. So _Eff_volume_table[128][mysample] would be the value of
+ *  mysample, at half volume.
+ */
+void *_Eff_build_volume_table_u8(void)
+{
+    int volume;
+    int sample;
+    Uint8 *rc;
+
+    if (!_Mix_effects_max_speed) {
+        return(NULL);
+    }
+
+    if (!_Eff_volume_table) {
+        rc = SDL_malloc(256 * 256);
+        if (rc) {
+            _Eff_volume_table = (void *) rc;
+            for (volume = 0; volume < 256; volume++) {
+                for (sample = -128; sample < 128; sample ++) {
+                    *rc = (Uint8)(((float) sample) * ((float) volume / 255.0))
+                        + 128;
+                    rc++;
+                }
+            }
+        }
+    }
+
+    return(_Eff_volume_table);
+}
+
+
+/* Build the volume table for Sint8-format samples.
+ *
+ * Each column of the table is a possible sample, while each row of the
+ *  table is a volume. Volume is a Uint8, where 0 is silence and 255 is full
+ *  volume. So _Eff_volume_table[128][mysample+128] would be the value of
+ *  mysample, at half volume.
+ */
+void *_Eff_build_volume_table_s8(void)
+{
+    int volume;
+    int sample;
+    Sint8 *rc;
+
+    if (!_Eff_volume_table) {
+        rc = SDL_malloc(256 * 256);
+        if (rc) {
+            _Eff_volume_table = (void *) rc;
+            for (volume = 0; volume < 256; volume++) {
+                for (sample = -128; sample < 128; sample ++) {
+                    *rc = (Sint8)(((float) sample) * ((float) volume / 255.0));
+                    rc++;
+                }
+            }
+        }
+    }
+
+    return(_Eff_volume_table);
+}
+
+
+/* end of effects.c ... */
+
+/* vi: set ts=4 sw=4 expandtab: */