1 files changed, 107 insertions, 0 deletions

diff --git a/src/audio/buf.c b/src/audio/buf.c
new file mode 100644
index 00000000..e61164d4
--- /dev/null
+++ b/src/audio/buf.c
@@ -0,0 +1,107 @@
+/* Copyright 2020 Jaakko Keränen <jaakko.keranen@iki.fi>
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
+
+#include "buf.h"
+
+iDefineTypeConstruction(InputBuf)
+
+void init_InputBuf(iInputBuf *d) {
+    init_Mutex(&d->mtx);
+    init_Condition(&d->changed);
+    init_Block(&d->data, 0);
+    d->isComplete = iTrue;
+}
+
+void deinit_InputBuf(iInputBuf *d) {
+    deinit_Block(&d->data);
+    deinit_Condition(&d->changed);
+    deinit_Mutex(&d->mtx);
+}
+
+size_t size_InputBuf(const iInputBuf *d) {
+    return size_Block(&d->data);
+}
+
+/*----------------------------------------------------------------------------------------------*/
+
+iDefineTypeConstructionArgs(SampleBuf, (SDL_AudioFormat format, size_t numChannels, size_t count),
+                            format, numChannels, count)
+
+void init_SampleBuf(iSampleBuf *d, SDL_AudioFormat format, size_t numChannels, size_t count) {
+    d->format      = format;
+    d->numChannels = numChannels;
+    d->sampleSize  = SDL_AUDIO_BITSIZE(format) / 8 * numChannels;
+    d->count       = count + 1; /* considered empty if head==tail */
+    d->data        = malloc(d->sampleSize * d->count);
+    d->head        = 0;
+    d->tail        = 0;
+    init_Condition(&d->moreNeeded);
+}
+
+void deinit_SampleBuf(iSampleBuf *d) {
+    deinit_Condition(&d->moreNeeded);
+    free(d->data);
+}
+
+size_t size_SampleBuf(const iSampleBuf *d) {
+    return d->head - d->tail;
+}
+
+size_t vacancy_SampleBuf(const iSampleBuf *d) {
+    return d->count - size_SampleBuf(d) - 1;
+}
+
+iBool isFull_SampleBuf(const iSampleBuf *d) {
+    return vacancy_SampleBuf(d) == 0;
+}
+
+void write_SampleBuf(iSampleBuf *d, const void *samples, const size_t n) {
+    iAssert(n <= vacancy_SampleBuf(d));
+    const size_t headPos = d->head % d->count;
+    const size_t avail   = d->count - headPos;
+    if (n > avail) {
+        const char *in = samples;
+        memcpy(ptr_SampleBuf_(d, headPos), in, d->sampleSize * avail);
+        in += d->sampleSize * avail;
+        memcpy(ptr_SampleBuf_(d, 0), in, d->sampleSize * (n - avail));
+    }
+    else {
+        memcpy(ptr_SampleBuf_(d, headPos), samples, d->sampleSize * n);
+    }
+    d->head += n;
+}
+
+void read_SampleBuf(iSampleBuf *d, const size_t n, void *samples_out) {
+    iAssert(n <= size_SampleBuf(d));
+    const size_t tailPos = d->tail % d->count;
+    const size_t avail   = d->count - tailPos;
+    if (n > avail) {
+        char *out = samples_out;
+        memcpy(out, ptr_SampleBuf_(d, tailPos), d->sampleSize * avail);
+        out += d->sampleSize * avail;
+        memcpy(out, ptr_SampleBuf_(d, 0), d->sampleSize * (n - avail));
+    }
+    else {
+        memcpy(samples_out, ptr_SampleBuf_(d, tailPos), d->sampleSize * n);
+    }
+    d->tail += n;
+}