Init

util/audio.c

@@ -0,0 +1,50 @@
+/*
+// Created by bruno on 16.2.2025.
+*/
+
+#include "audio.h"
+
+AudioData audioData;
+
+void audio_callback(void *userdata, Uint8 *stream, int len) {
+    AudioData *audio = (AudioData *) userdata;
+    int samples = len / sizeof(float);
+
+    for (int i = 0; i < samples; i++) {
+        float mix = 0.0f;
+        int activeVoices = 0;
+
+        for (int v = 0; v < NUM_SYNTH_VOICES; v++) {
+            SynthVoice *voice = &audio->synthVoices[v];
+            if (voice->volume == 0 || voice->frequency == 0) continue;
+
+            float sample = 0.0f;
+            float t = (float) voice->phase / 255.0f * 2.0f - 1.0f;
+
+            switch (voice->waveform) {
+                default:
+                case WAVE_SINE:
+                    sample = sinf(voice->phase * 2.0f * M_PI / 256.0f);
+                    break;
+                case WAVE_SQUARE:
+                    sample = (t >= 0.0f) ? 1.0f : -1.0f;
+                    break;
+                case WAVE_SAWTOOTH:
+                    sample = t;
+                    break;
+                case WAVE_TRIANGLE:
+                    sample = (t < 0) ? -t : t;
+                    break;
+                case WAVE_NOISE:
+                    sample = ((float) rand() / RAND_MAX) * 2.0f - 1.0f;
+                    break;
+            }
+
+            voice->phase += (uint8_t) ((voice->frequency * 256) / SAMPLE_RATE);
+            mix += sample * (voice->volume / 255.0f);
+            activeVoices++;
+        }
+
+        ((float *) stream)[i] = (activeVoices > 0) ? mix / activeVoices : 0.0f;
+    }
+}

util/audio.h

@@ -0,0 +1,39 @@
+/*
+// Created by bruno on 16.2.2025.
+*/
+
+#ifndef RISCB_AUDIO_H
+#define RISCB_AUDIO_H
+
+#include <SDL2/SDL.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define SAMPLE_RATE 44100
+#define NUM_SYNTH_VOICES 3
+
+typedef enum {
+    WAVE_SINE,
+    WAVE_SQUARE,
+    WAVE_SAWTOOTH,
+    WAVE_TRIANGLE,
+    WAVE_NOISE
+} Waveform;
+
+typedef struct {
+    uint8_t volume;
+    uint16_t frequency;
+    uint8_t phase;
+    Waveform waveform;
+} SynthVoice;
+
+typedef struct {
+    SynthVoice synthVoices[NUM_SYNTH_VOICES];
+} AudioData;
+
+extern AudioData audioData;
+
+void audio_callback(void *userdata, Uint8 *stream, int len);
+
+#endif //RISCB_AUDIO_H

util/font.c

@@ -0,0 +1,61 @@
+//
+// Created by bruno on 1.2.2025.
+//
+
+#include "font.h"
+
+BitmapFont
+prepText(SDL_Renderer *renderer, unsigned char pxSize, const char *file, uint8_t r, uint8_t g, uint8_t b, uint8_t a) {
+    TTF_Font *gFont = TTF_OpenFont(file, pxSize);
+    BitmapFont out;
+    out.size = pxSize;
+    out.color = (SDL_Color) {r, g, b, a};
+    unsigned int i = 1;
+    do {
+        if (i == 173) { //specifically this char is 0 width (IDK why)
+            out.surface[i] = SDL_CreateRGBSurface(0, pxSize, pxSize, 32, 0, 0, 0, 0);
+        } else {
+            char tmpOut[2] = {i, 0};
+            out.surface[i] = TTF_RenderText_Solid(gFont, tmpOut, out.color);
+        }
+        out.texture[i] = SDL_CreateTextureFromSurface(renderer, out.surface[i]);
+        i++;
+    } while (i < 256);
+
+    TTF_CloseFont(gFont);
+    return out;
+}
+
+void renderText(SDL_Renderer *renderer, BitmapFont font, char *string, uint16_t x, uint16_t y) {
+    SDL_Rect charRect;
+    charRect.x = 0;
+    charRect.y = 0;
+    charRect.w = font.size;
+    charRect.h = font.size;
+    SDL_Rect outRect = charRect;
+    outRect.x = x;
+    outRect.y = y;
+
+    while (*string) {
+        if (*string == '\n') {
+            outRect.x = x;
+            outRect.y += charRect.h + 4;
+            string++;
+            continue;
+        }
+        SDL_RenderCopy(renderer, font.texture[*string], &charRect, &outRect);
+        outRect.x += charRect.w + 1;
+        string++;
+    }
+}
+
+void destroyFont(BitmapFont *font) {
+    for (uint16_t i = 1; i < 256; i++) {
+        if (font->texture[i]) {
+            SDL_DestroyTexture(font->texture[i]);
+        }
+        if (font->surface[i]) {
+            SDL_FreeSurface(font->surface[i]);
+        }
+    }
+}

util/font.h

@@ -0,0 +1,26 @@
+//
+// Created by bruno on 1.2.2025.
+//
+
+#ifndef RISCB_FONT_H
+#define RISCB_FONT_H
+
+#include <SDL2/SDL_render.h>
+#include <SDL2/SDL_ttf.h>
+#include <math.h>
+
+typedef struct {
+    SDL_Texture *texture[256];
+    SDL_Surface *surface[256];
+    uint8_t size;
+    SDL_Color color;
+} BitmapFont;
+
+BitmapFont
+prepText(SDL_Renderer *renderer, unsigned char pxSize, const char *file, uint8_t r, uint8_t g, uint8_t b, uint8_t a);
+
+void destroyFont(BitmapFont *font);
+
+void renderText(SDL_Renderer *renderer, BitmapFont font, char *string, uint16_t x, uint16_t y);
+
+#endif //RISCB_FONT_H