shadermeh/shadermeh.c

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/* SPDX-License-Identifier: ISC */
/*
* shadermeh.c
*
* Copyright (C) 2022 David Oberhollenzer <goliath@infraroot.at>
*/
#include "shadermeh.h"
static GLfloat vertex_buffer[] = {
-1.0f, -1.0f, 0.0f, /* lower left corner */
1.0f, 1.0f, 1.0f,
+1.0f, -1.0f, 0.0f, /* lower right corner */
1.0f, 1.0f, 1.0f,
-1.0f, 1.0f, 0.0f, /* uper left corner */
1.0f, 1.0f, 1.0f,
+1.0f, +1.0f, 0.0f, /* upper right corner */
1.0f, 1.0f, 1.0f,
};
static GLubyte audio_buffer[AUDIO_SAMPLES * AUDIO_CHANNELS];
size_t sample_pointer = 0;
size_t sample_data_pointer = 0;
size_t sample_rate = 0;
static float *audio_sample_data;
static float *audio_receive_data;
static double *fftw_in;
static fftw_complex *fftw_out;
static fftw_plan plan;
static int try_fetch_audio(float iTimeDelta)
{
/* To avoid generating stale images, we keep our own sample buffer,
* which is then used to move a sliding window of data for the fft and
* wave samples. We need to do this, as otherwise we would set an upper
* limit of fps (20 at 4800kHz sample rate), which would not be good.
* The size of the window is set in the header file. The with our
* approach is that the buffer allows for drifting to occur within the
* buffer limits. If you buffer is 3s long the delay can grow to 3s.
* Choose your buffer size wisely for your application.
*/
size_t i;
ssize_t ret = 0;
memset(audio_receive_data, 0, AUDIO_BUFFER_SIZE *
sizeof(*audio_receive_data));
sample_pointer += (sample_rate * iTimeDelta);
for (;;) {
ret = read(STDIN_FILENO, (char *)audio_receive_data,
sizeof(*audio_receive_data)*AUDIO_BUFFER_SIZE);
if (ret < 0) {
if (errno == EINTR)
continue;
if (errno == EAGAIN || errno == EWOULDBLOCK)
break;
perror("stdin");
return -1;
}
if (ret == 0 || ret % sizeof(float) != 0){
break;
}
ret /= 4;
if((ret + sample_pointer) > AUDIO_BUFFER_SIZE){
/* Not enough storage space to store all new audio data,
* will override not output data with new one */
memset(audio_sample_data, 0,
AUDIO_BUFFER_SIZE * sizeof(*audio_sample_data));
memcpy(audio_sample_data, audio_receive_data,
ret * sizeof(*audio_sample_data));
sample_pointer = 0;
sample_data_pointer = ret;
}else{
memmove(audio_sample_data,
&audio_sample_data[sample_pointer],
(AUDIO_BUFFER_SIZE - sample_pointer)*
sizeof(*audio_sample_data));
if(sample_data_pointer <= sample_pointer){
sample_data_pointer = 0;
}else{
sample_data_pointer -= sample_pointer;
}
sample_pointer = 0;
size_t len = ret;
if((ret + sample_data_pointer) >= AUDIO_BUFFER_SIZE){
len = AUDIO_BUFFER_SIZE - sample_data_pointer;
}
memcpy(&audio_sample_data[sample_data_pointer],
audio_receive_data, len * sizeof(float));
sample_data_pointer += len;
break;
}
}
if((sample_pointer+AUDIO_FFT_SIZE) >= sample_data_pointer){
fprintf(stderr, "shadermeh input to slow %zu > %zu! wrapping around!\n", sample_pointer+AUDIO_FFT_SIZE, sample_data_pointer);
sample_pointer = 0;
}
memset(fftw_in, 0, sizeof(*fftw_in) * AUDIO_BUFFER_SIZE);
memset(fftw_out, 0, sizeof(*fftw_out) * AUDIO_BUFFER_SIZE);
for (i = 0; i < AUDIO_FFT_SIZE; ++i)
fftw_in[i] = audio_sample_data[sample_pointer+i];
fftw_execute(plan);
for (i = 0; i < AUDIO_SAMPLES; ++i) {
float a = cabs(fftw_out[i]);
audio_buffer[i + AUDIO_SAMPLES] = audio_sample_data[sample_pointer+i] * 127.0f + 127.0f;
audio_buffer[i] = log(fabsf(a)+1) * 50;
}
return 0;
}
static double diff_timespec(const struct timespec *time1,
const struct timespec *time0)
{
return (time1->tv_sec - time0->tv_sec)
+ (time1->tv_nsec - time0->tv_nsec) / 1000000000.0;
}
static void convert_for_ffmpeg(const uint8_t *in, uint8_t *out,
size_t width, size_t height)
{
size_t x, y;
for (y = 0; y < height; ++y) {
const uint8_t *src = in + y * width * 4;
uint8_t *dst = out + (height - 1 - y) * width * 3;
for (x = 0; x < width; ++x) {
*(dst++) = *(src++);
*(dst++) = *(src++);
*(dst++) = *(src++);
++src;
}
}
}
static int wait_fd_event(int fd, int events)
{
struct pollfd pfd;
int ret;
for (;;) {
pfd.fd = fd;
pfd.events = events;
pfd.revents = 0;
ret = poll(&pfd, 1, -1);
if (ret > 0) {
if (pfd.revents & events)
break;
if (pfd.revents & (POLLERR | POLLHUP)) {
fputs("poll reported error\n", stderr);
return -1;
}
}
if (ret < 0) {
if (errno == EINTR)
continue;
perror("poll");
return -1;
}
}
return 0;
}
static int write_retry(int fd, const void *buffer, size_t size)
{
while (size > 0) {
int ret = write(fd, buffer, size);
if (ret < 0) {
if (errno == EINTR)
continue;
if (errno == EAGAIN) {
if (wait_fd_event(fd, POLLOUT))
return -1;
continue;
}
perror("write");
return -1;
}
if (ret == 0)
return -1;
size -= ret;
buffer = (const char *)buffer + ret;
}
return 0;
}
static const struct option long_opts[] = {
{ "width", required_argument, NULL, 'w' },
{ "height", required_argument, NULL, 'h' },
{ "shader", required_argument, NULL, 's' },
{ "to-stdout", no_argument, NULL, 'S' },
{ "stdin-audio", required_argument, NULL, 'a' },
{ NULL, 0, NULL, 0 },
};
static const char *short_opts = "w:a:h:s:S";
static const char *usage_str =
"shadermeh OPTIONS...\n"
"\n"
"Possible options:\n"
"\n"
" --width, -w <pixels>\n"
" --height, -h <pixels>\n"
"\n"
" --to-stdout, -S Poop raw RGB24 frames to stdout (blocking)\n"
" --stdin-audio, -a <sample rate> Read raw PCM audio from stdin (non-blocking)\n"
"\n"
" --shader, -s <shader file>\n"
"\n";
int main(int argc, char **argv)
{
GLuint vao, vbo, fbo, fbo_tex, sound_tex, sampler_sound;
GLuint u_iResolution, u_iTime, u_iTimeDelta, u_iFrame;
struct timespec start, frame_start, frame_end;
unsigned int width, height, iFrame = 0;
void *fb32 = NULL, *fb24 = NULL;
const char *shader_file = NULL;
GLint major, minor, prog;
float iTime, iTimeDelta = 0;
bool have_audio = false;
bool to_stdout = false;
window *wnd;
int i;
/******************** parse options ************************/
width = 800;
height = 450;
for (;;) {
i = getopt_long(argc, argv, short_opts, long_opts, NULL);
if (i == -1)
break;
switch (i) {
case 'w':
width = strtol(optarg, NULL, 10);
break;
case 'h':
height = strtol(optarg, NULL, 10);
break;
case 's':
shader_file = optarg;
break;
case 'S':
to_stdout = true;
break;
case 'a':
have_audio = true;
sample_rate = strtol(optarg, NULL, 10);
audio_sample_data = malloc(AUDIO_BUFFER_SIZE *
sizeof(float));
audio_receive_data = malloc(AUDIO_BUFFER_SIZE *
sizeof(float));
break;
default:
fputs(usage_str, stderr);
return EXIT_FAILURE;
}
}
if (have_audio) {
int flags = fcntl(STDIN_FILENO, F_GETFL, 0);
if (fcntl(STDIN_FILENO, F_SETFL, flags | O_NONBLOCK)) {
perror("making stdin non-blocking");
return EXIT_FAILURE;
}
}
if (!shader_file) {
fputs(usage_str, stderr);
fputs("No shader file specified!\n", stderr);
return EXIT_FAILURE;
}
if (to_stdout) {
fb32 = calloc(1, width * height * 4);
if (!fb32) {
perror("allocating scratch framebuffer");
return EXIT_FAILURE;
}
fb24 = calloc(1, width * height * 3);
if (!fb24) {
perror("allocating scratch framebuffer");
free(fb32);
return EXIT_FAILURE;
}
}
/********** create window and make context current **********/
wnd = window_create(width, height, "shader meh...");
if (!wnd) {
fputs("failed to create window", stderr);
free(fb32);
free(fb24);
return EXIT_FAILURE;
}
window_make_current(wnd);
window_set_vsync(wnd, 1);
/******************** load entry points ********************/
glewExperimental = GL_TRUE;
if (glewInit() != GLEW_OK) {
fputs("glewInit() error", stderr);
window_destroy(wnd);
free(fb32);
free(fb24);
return EXIT_FAILURE;
}
glGetIntegerv(GL_MAJOR_VERSION, &major);
glGetIntegerv(GL_MINOR_VERSION, &minor);
if (!to_stdout)
printf("OpenGL version %d.%d\n", major, minor);
/******************** initialization ********************/
glViewport(0, 0, width, height);
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
/* vertex buffer object & vertex array object */
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
glGenBuffers(1, &vbo);
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_buffer),
vertex_buffer, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 6, 0);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 6,
(GLvoid *)(3 * sizeof(GLfloat)));
/* shader */
prog = shader_program_load(shader_file);
if (!shader_program_get_build_status(prog)) {
shader_program_print_info_log(prog);
goto fail_vao;
}
glUseProgram(prog);
/* uniforms */
u_iResolution = glGetUniformLocation(prog, "iResolution");
u_iTime = glGetUniformLocation(prog, "iTime");
u_iTimeDelta = glGetUniformLocation(prog, "iTimeDelta");
u_iFrame = glGetUniformLocation(prog, "iFrame");
glUniform3f(u_iResolution, width, height, 0.0f);
glUniform1i(glGetUniformLocation(prog, "iChannel0"), 0);
/************************* textures *************************/
glGenTextures(1, &sound_tex);
glBindTexture(GL_TEXTURE_2D, sound_tex);
glTexImage2D(GL_TEXTURE_2D, 0, GL_R8,
AUDIO_SAMPLES, AUDIO_CHANNELS, 0,
GL_RED, GL_UNSIGNED_BYTE, audio_buffer);
glBindTexture(GL_TEXTURE_2D, 0);
glGenSamplers(1, &sampler_sound);
glSamplerParameteri(sampler_sound, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glSamplerParameteri(sampler_sound, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glBindSampler(0, sampler_sound);
if (have_audio) {
fftw_in = fftw_alloc_real(AUDIO_BUFFER_SIZE);
fftw_out = fftw_alloc_complex(AUDIO_BUFFER_SIZE);
if(fftw_in == NULL || fftw_out == NULL)
goto fail_vao;
plan = fftw_plan_dft_r2c_1d(AUDIO_BUFFER_SIZE, fftw_in, fftw_out,
FFTW_MEASURE);
}
/******************** framebuffer object ********************/
if (to_stdout) {
glGenFramebuffers(1, &fbo);
glGenTextures(1, &fbo_tex);
glBindTexture(GL_TEXTURE_2D, fbo_tex);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0,
GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glBindTexture(GL_TEXTURE_2D, 0);
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
fbo_tex, 0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
} else {
window_show(wnd);
}
/******************** drawing loop ********************/
clock_gettime(CLOCK_MONOTONIC_RAW, &start);
while (to_stdout || window_handle_events()) {
/* render image to FBO */
clock_gettime(CLOCK_MONOTONIC_RAW, &frame_start);
if (to_stdout)
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
glClear(GL_COLOR_BUFFER_BIT);
if (have_audio) {
if (try_fetch_audio(iTimeDelta))
break;
glBindTexture(GL_TEXTURE_2D, sound_tex);
glTexImage2D(GL_TEXTURE_2D, 0, GL_R8,
AUDIO_SAMPLES, AUDIO_CHANNELS, 0,
GL_RED, GL_UNSIGNED_BYTE, audio_buffer);
}
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glBindTexture(GL_TEXTURE_2D, 0);
if (to_stdout) {
glFlush();
} else {
window_swap_buffers(wnd);
}
/* get image from FBO, dump to stdout */
if (to_stdout) {
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glBindTexture(GL_TEXTURE_2D, fbo_tex);
glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA,
GL_UNSIGNED_BYTE, fb32);
glBindTexture(GL_TEXTURE_2D, 0);
convert_for_ffmpeg(fb32, fb24, width, height);
if (write_retry(STDOUT_FILENO, fb24,
width * height * 3)) {
break;
}
}
/* update timers */
clock_gettime(CLOCK_MONOTONIC_RAW, &frame_end);
iFrame += 1;
iTimeDelta = diff_timespec(&frame_end, &frame_start);
iTime = diff_timespec(&frame_end, &start);
glUniform1f(u_iTimeDelta, iTimeDelta);
glUniform1f(u_iTime, iTime);
glUniform1ui(u_iFrame, iFrame);
}
/******************** cleanup ********************/
glDeleteTextures(1, &sound_tex);
glDeleteSamplers(1, &sampler_sound);
if (to_stdout) {
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glDeleteFramebuffers(1, &fbo);
glDeleteTextures(1, &fbo_tex);
}
glUseProgram(0);
glDeleteProgram(prog);
if (have_audio) {
fftw_destroy_plan(plan);
}
fail_vao:
glBindBuffer(GL_ARRAY_BUFFER, 0);
glDeleteBuffers(1, &vbo);
glBindVertexArray(0);
glDeleteVertexArrays(1, &vao);
window_make_current(NULL);
free(fb32);
free(fb24);
fftw_free(fftw_in);
fftw_free(fftw_out);
window_destroy(wnd);
return EXIT_SUCCESS;
}