Add project source code

2 files changed, 205 insertions, 0 deletions

diff --git a/src/sfx/ps1/inc/sfx/port.h b/src/sfx/ps1/inc/sfx/port.h
new file mode 100644
index 0000000..80c97e8
--- /dev/null
+++ b/src/sfx/ps1/inc/sfx/port.h
@@ -0,0 +1,17 @@
+#ifndef SFX_PS1_H
+#define SFX_PS1_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+typedef uint32_t sfx_spu_addr;
+typedef uint8_t sfx_spu_voice;
+
+struct sound
+{
+    sfx_spu_addr addr;
+    uint16_t sample_rate;
+    sfx_spu_voice voice;
+};
+
+#endif /* SFX_PS1_H */
diff --git a/src/sfx/ps1/src/sound.c b/src/sfx/ps1/src/sound.c
new file mode 100644
index 0000000..e0377c7
--- /dev/null
+++ b/src/sfx/ps1/src/sound.c
@@ -0,0 +1,188 @@
+#include <sfx.h>
+#include <sfx/port.h>
+#include <psxspu.h>
+#include <ctype.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+void sfx_free(struct sound *const s)
+{
+}
+
+void sfx_deinit(void)
+{
+}
+
+static int vag_ntohs(int n)
+{
+    return (n & 0xFF) << 24
+        | (n & 0xFF00) << 16
+        | (n & 0xFF0000) >> 8
+        | (n & 0xFF000000) >> 24;
+}
+
+static const char magic[] = "VAGp";
+
+struct vag_header
+{
+    char magic_bytes[sizeof magic - 1];
+    uint32_t version;
+    uint32_t :32;
+    uint32_t size;
+    uint32_t sample_rate;
+    uint8_t reserved[12];
+    char name[16];
+};
+
+static int get_header(struct vag_header *const h, FILE *const f)
+{
+    int ret = -1;
+
+    if (!fread(h, sizeof *h, 1, f))
+    {
+        fprintf(stderr, "VAG header not found\n");
+        goto end;
+    }
+    else if (strncmp(h->magic_bytes, magic, sizeof h->magic_bytes))
+    {
+        fprintf(stderr, "Expected magic bytes \"%s\", found: ", magic);
+        enum {N = sizeof h->magic_bytes / sizeof *h->magic_bytes};
+
+        for (size_t i = 0; i < N; i++)
+        {
+            const char c = h->magic_bytes[i];
+
+            fprintf(stderr, "[%zu] = %#x", i, c);
+
+            if ((i + 1) < N)
+                fprintf(stderr, ", ");
+
+            if (isalnum(c))
+                fprintf(stderr, "(%c)", c);
+        }
+
+        putchar('\n');
+        goto end;
+    }
+
+    /* File data is stored as big endian for some reason. */
+    h->version = vag_ntohs(h->version);
+    h->sample_rate = vag_ntohs(h->sample_rate);
+    h->size = vag_ntohs(h->size);
+    ret = 0;
+
+end:
+    return ret;
+}
+
+static sfx_spu_addr cur_addr = SPU_DATA_BASE_ADDR;
+
+static int upload_vag(const struct vag_header *const h,
+    struct sound *const s, FILE *const f)
+{
+    enum {SPU_RAM = 512 << 10};
+    const sfx_spu_addr end_addr = cur_addr + h->size;
+
+    if (end_addr >= SPU_RAM)
+    {
+        fprintf(stderr, "maximum SPU address exceeded (%#x, max %#x)\n",
+            end_addr, SPU_RAM);
+        return -1;
+    }
+
+    s->addr = cur_addr;
+    s->sample_rate = h->sample_rate;
+
+    for (size_t i = 0; i < h->size; /* See loop body. */)
+    {
+        /* From https://problemkaputt.de/psx-spx.htm#soundprocessingunitspu :
+         * "Sound RAM Data Transfer Fifo" supports up to 32 samples. */
+        uint16_t hwords[32];
+        const size_t rem = h->size - i;
+        const size_t n = rem > sizeof hwords ? sizeof hwords : rem;
+
+        if (!fread(&hwords, n, 1, f))
+        {
+            fprintf(stderr, "%s: failed to read %zu bytes\n", __func__, n);
+            return -1;
+        }
+
+        SsUpload(&hwords, n, cur_addr);
+        cur_addr += n;
+        i += n;
+    }
+
+#if 0
+    const unsigned used = cur_addr - SPU_DATA_BASE_ADDR;
+    printf("SPU RAM: %u bytes (%u%%)\n", used, (used * 100) / (SPU_RAM - SPU_DATA_BASE_ADDR));
+#endif
+    return 0;
+}
+
+typedef volatile struct
+{
+    uint16_t l_vol, r_vol;
+    uint16_t adpcm_sample_rate;
+    uint16_t adpcm_start_addr;
+
+    union
+    {
+        struct
+        {
+            uint32_t sustain_lvl :4;
+            uint32_t decay_shift :4;
+            uint32_t attack_step :2;
+            uint32_t attack_shift :5;
+            uint32_t attack_mode :1;
+            uint32_t release_shift :5;
+            uint32_t release_mode :1;
+            uint32_t sustain_step :2;
+            uint32_t sustain_shift :5;
+            uint32_t :1;
+            uint32_t sustain_dir :1;
+            uint32_t sustain_mode :1;
+        } bit;
+
+        uint32_t mask;
+    } adsr;
+
+    uint16_t adsr_vol;
+    uint16_t adsr_repeat_addr;
+} *spu_voice;
+
+#define SPU_VOICE ((spu_voice)0x1f801c00)
+
+int sfx_play(const struct sound *const s)
+{
+    const sfx_spu_voice voice = s->voice;
+
+    SPU_VOICE[voice].adpcm_sample_rate = SsFreqToPitch(s->sample_rate);
+    SPU_VOICE[voice].adpcm_start_addr = s->addr >> 3;
+    SPU_VOICE[voice].l_vol = 0x3FFF;
+    SPU_VOICE[voice].r_vol = 0x3FFF;
+
+    if (voice > sizeof SPU_KEY_ON1 * 8)
+        SPU_KEY_ON2 = 1 << (voice - sizeof SPU_KEY_ON1 * 8);
+    else
+        SPU_KEY_ON1 = 1 << voice;
+
+    return 0;
+}
+
+int sfx_sound_from_fp(struct sound *const s, FILE *const f)
+{
+    struct vag_header h;
+
+    if (get_header(&h, f) || upload_vag(&h, s, f))
+        return -1;
+
+    return 0;
+}
+
+int sfx_init(void)
+{
+    SsInit();
+    return 0;
+}