Add more audio shaders

Signed-off-by: tyrolyean <tyrolyean@tyrolyean.net>

Makefile

@@ -1,5 +1,5 @@
-CFLAGS = -ansi -pedantic -Wall -Wextra -O2 -Ofast -D_DEFAULT_SOURCE
-LDFLAGS = -lX11 -lGL -lGLEW -lm -lrt
+CFLAGS = -std=c11 -pedantic -Wall -Wextra -O2 -Ofast -D_DEFAULT_SOURCE
+LDFLAGS = -lX11 -lGL -lGLEW -lfftw3 -lm -lrt
 
 shadermeh: shadermeh.o window.o shader.o
 

shader.c

@@ -31,6 +31,7 @@ static const char *frag_src_pre =
 "uniform vec4 iDate;\n"
 "uniform float iSampleRate;\n"
 "uniform vec3 iChannelResolution[4];\n"
+"uniform sampler2D iChannel0;"
 "\n";
 
 static const char *frag_src_post =

shadermeh.c

@@ -20,6 +20,107 @@ static GLfloat vertex_buffer[] = {
 	 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)
 {
@@ -45,6 +146,39 @@ static void convert_for_ffmpeg(const uint8_t *in, uint8_t *out,
 	}
 }
 
+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) {
@@ -53,6 +187,13 @@ static int write_retry(int fd, const void *buffer, size_t size)
 		if (ret < 0) {
 			if (errno == EINTR)
 				continue;
+
+			if (errno == EAGAIN) {
+				if (wait_fd_event(fd, POLLOUT))
+					return -1;
+				continue;
+			}
+
 			perror("write");
 			return -1;
 		}
@@ -72,10 +213,11 @@ static const struct option long_opts[] = {
  	{ "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:h:s:S";
+static const char *short_opts = "w:a:h:s:S";
 
 static const char *usage_str =
 "shadermeh OPTIONS...\n"
@@ -85,21 +227,23 @@ static const char *usage_str =
 "  --width, -w <pixels>\n"
 "  --height, -h <pixels>\n"
 "\n"
-"  --to-stdout, -S\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;
-	GLuint vao, vbo, fbo, fbo_tex;
 	GLint major, minor, prog;
-	float iTime, iTimeDelta;
+	float iTime, iTimeDelta = 0;
+	bool have_audio = false;
 	bool to_stdout = false;
 	window *wnd;
 	int i;
@@ -126,12 +270,29 @@ int main(int argc, char **argv)
 		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);
@@ -179,6 +340,8 @@ int main(int argc, char **argv)
 
 	glGetIntegerv(GL_MAJOR_VERSION, &major);
 	glGetIntegerv(GL_MINOR_VERSION, &minor);
+
+	if (!to_stdout)
 		printf("OpenGL version %d.%d\n", major, minor);
 
 	/******************** initialization ********************/
@@ -207,6 +370,7 @@ int main(int argc, char **argv)
 
 	if (!shader_program_get_build_status(prog)) {
 		shader_program_print_info_log(prog);
+		goto fail_vao;
 	}
 
 	glUseProgram(prog);
@@ -215,11 +379,34 @@ int main(int argc, char **argv)
 	u_iResolution = glGetUniformLocation(prog, "iResolution");
 	u_iTime = glGetUniformLocation(prog, "iTime");
 	u_iTimeDelta = glGetUniformLocation(prog, "iTimeDelta");
-	u_iFrame = glGetUniformLocation(prog, "iFrame;");
+	u_iFrame = glGetUniformLocation(prog, "iFrame");
 
 	glUniform3f(u_iResolution, width, height, 0.0f);
 
-	clock_gettime(CLOCK_MONOTONIC_RAW, &start);
+	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) {
@@ -229,20 +416,42 @@ int main(int argc, char **argv)
 		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();
@@ -252,9 +461,14 @@ int main(int argc, char **argv)
 
 		/* 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,
@@ -276,12 +490,8 @@ int main(int argc, char **argv)
 	}
 
 	/******************** cleanup ********************/
-	glUseProgram(0);
-	glBindBuffer(GL_ARRAY_BUFFER, 0);
-	glDeleteBuffers(1, &vbo);
-	glBindVertexArray(0);
-	glDeleteVertexArrays(1, &vao);
-	glDeleteProgram(prog);
+	glDeleteTextures(1, &sound_tex);
+	glDeleteSamplers(1, &sampler_sound);
 
 	if (to_stdout) {
 		glBindFramebuffer(GL_FRAMEBUFFER, 0);
@@ -289,9 +499,23 @@ int main(int argc, char **argv)
 		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;
 }

shadermeh.h

@@ -23,8 +23,19 @@
 #include <unistd.h>
 #include <stdio.h>
 #include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
 #include <time.h>
 
+#include <math.h>
+#include <complex.h>
+#include <fftw3.h>
+
+#define AUDIO_SAMPLES (4096)
+#define AUDIO_BUFFER_SIZE (sample_rate * 3)
+#define AUDIO_FFT_SIZE (AUDIO_SAMPLES * 2)
+#define AUDIO_CHANNELS (2)
+
 typedef struct {
 	Window wnd;
 	GLXContext gl;

shaders/eclipse.frag

@@ -0,0 +1,84 @@
+// credit: https://www.shadertoy.com/view/4tGXzt
+
+#define BEATMOVE 1
+
+const float FREQ_RANGE = 64.0;
+const float PI = 3.1415;
+const float RADIUS = 0.6;
+const float BRIGHTNESS = 0.2;
+const float SPEED = 0.5;
+
+//convert HSV to RGB
+vec3 hsv2rgb(vec3 c){
+    vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+    vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
+    return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
+}
+
+float luma(vec3 color) {
+  return dot(color, vec3(0.299, 0.587, 0.114));
+}
+
+float getfrequency(float x) {
+	return texture(iChannel0, vec2(floor(x * FREQ_RANGE + 1.0) / FREQ_RANGE, 0.25)).x + 0.06;
+}
+
+float getfrequency_smooth(float x) {
+	float index = floor(x * FREQ_RANGE) / FREQ_RANGE;
+    float next = floor(x * FREQ_RANGE + 1.0) / FREQ_RANGE;
+	return mix(getfrequency(index), getfrequency(next), smoothstep(0.0, 1.0, fract(x * FREQ_RANGE)));
+}
+
+float getfrequency_blend(float x) {
+    return mix(getfrequency(x), getfrequency_smooth(x), 0.5);
+}
+
+vec3 doHalo(vec2 fragment, float radius) {
+	float dist = length(fragment);
+	float ring = 1.0 / abs(dist - radius);
+	
+	float b = dist < radius ? BRIGHTNESS * 0.3 : BRIGHTNESS;
+	
+	vec3 col = vec3(0.0);
+	
+	float angle = atan(fragment.x, fragment.y);
+	col += hsv2rgb( vec3( ( angle + iTime * 0.25 ) / (PI * 2.0), 1.0, 1.0 ) ) * ring * b;
+	
+	float frequency = max(getfrequency_blend(abs(angle / PI)) - 0.02, 0.0);
+	col *= frequency;
+	
+	// Black halo
+	col *= smoothstep(radius * 0.5, radius, dist);
+	
+	return col;
+}
+
+vec3 doLine(vec2 fragment, float radius, float x) {
+	vec3 col = hsv2rgb(vec3(x * 0.23 + iTime * 0.12, 1.0, 1.0));
+	
+	float freq = abs(fragment.x * 0.5);
+	
+	col *= (1.0 / abs(fragment.y)) * BRIGHTNESS * getfrequency(freq);	
+	col = col * smoothstep(radius, radius * 1.8, abs(fragment.x));
+	
+	return col;
+}
+
+
+void mainImage( out vec4 fragColor, in vec2 fragCoord ) {
+    vec2 fragPos = fragCoord / iResolution.xy;
+	fragPos = (fragPos - 0.5) * 2.0;
+    fragPos.x *= iResolution.x / iResolution.y;
+	
+	vec3 color = vec3(0.0134, 0.052, 0.1);
+	color += doHalo(fragPos, RADIUS);
+
+    float c = cos(iTime * SPEED);
+    float s = sin(iTime * SPEED);
+    vec2 rot = mat2(c,s,-s,c) * fragPos;
+	color += doLine(rot, RADIUS, rot.x);
+	
+	color += max(luma(color) - 1.0, 0.0);
+    
+	fragColor = vec4(color, 1.0);
+}

shaders/fft.frag

@@ -0,0 +1,65 @@
+/*
+
+	Linear vs Logarithmic FFT
+
+	some good test songs:
+
+	https://soundcloud.com/kraddy/winning
+	https://soundcloud.com/grey-houston/soothing-piano-melody
+	https://soundcloud.com/pointpoint/life-in-gr
+
+*/
+
+//from https://stackoverflow.com/questions/35799286
+float toLog(float value, float min, float max){
+	float exp = (value-min) / (max-min);
+	return min * pow(max/min, exp);
+}
+
+float getLevel(float samplePos){
+    // the sound texture is 512x2
+	int tx = int(samplePos*512.0);
+	// first row is frequency data (48Khz/4 in 512 texels, meaning 23 Hz per texel)
+	return texelFetch( iChannel0, ivec2(tx,0), 0 ).x; 
+}
+
+
+void mainImage( out vec4 fragColor, in vec2 fragCoord )
+{
+	vec2 uv = fragCoord.xy / iResolution.xy;
+	
+    float xPos;
+    float fft;
+    
+    if (uv.y > 0.5){
+          
+        //linear sampling
+        xPos = uv.x;
+        fft = getLevel(xPos);
+        
+    }else{
+        
+        //crop bottom and top of range
+        uv.x = mix(0.3,0.7, uv.x);
+        
+        //logarithmic sampling
+        xPos = toLog(uv.x, 0.01, 1.0);
+
+        fft = getLevel(xPos);
+        
+        //boost contrast
+        fft = pow(fft,3.0);
+        
+        //boost gain
+        fft *= 1.5;
+        
+        //contrast / brightness
+        float contrast = 1.4;
+        float brightness = 0.;
+        fft = (fft - 0.5) * contrast + 0.5 + brightness;
+        
+    }
+    
+    fragColor = vec4(vec3(fft),1.0);
+       
+}

shaders/grid.frag

@@ -0,0 +1,158 @@
+//https://www.shadertoy.com/view/XlBXRh with mic not soundcloud
+#define preset4
+
+#ifdef preset1
+	#define cells vec2(14.,14.)
+	#define persp 1.5
+	#define height 1.
+	#define linewidth .5
+	#define lineexp 4.
+	#define brightness .7
+#endif
+
+
+#ifdef preset2
+	#define cells vec2(10.,5.)
+	#define persp 2.5
+	#define height 1.
+	#define linewidth 3.
+	#define lineexp 6.
+	#define brightness .4
+#endif
+
+
+#ifdef preset3
+	#define OPAQUE_MODE
+	#define INVERSE
+	#define cells vec2(16.,16.)
+	#define persp 1.
+	#define height 1.5
+	#define linewidth .1
+	#define lineexp .5
+	#define brightness .8
+#endif
+
+#ifdef preset4
+	#define OPAQUE_MODE
+	#define cells vec2(10.,10.)
+	#define persp 2.
+	#define height .75
+	#define linewidth .2
+	#define lineexp 1.
+	#define brightness 1.5
+#endif
+
+#ifdef preset5
+	#define INVERSE
+	#define cells vec2(6.,25.)
+	#define persp 1.
+	#define height 2.
+	#define linewidth .07
+	#define lineexp .3
+	#define brightness .35
+#endif
+
+
+#ifdef preset6
+	#define INVERSE
+	#define OPAQUE_MODE
+	#define cells vec2(15.,15.)
+	#define persp 2.5
+	#define height 1.
+	#define linewidth .05
+	#define lineexp .5
+	#define brightness 1.
+#endif
+
+
+
+
+#define hcells (cells*.5)
+
+
+vec3 segment(vec2 p, vec3 from, vec3 to, float width, float dist) {
+width=1./width;
+vec2 seg=from.xy-to.xy;
+float halfdist=distance(from.xy,to.xy)*.5;
+float ang=atan(seg.y,seg.x);
+float sine=sin(ang);
+float cose=cos(ang);
+p-=from.xy; 
+p*=mat2(cose,sine,-sine,cose);
+float dx=abs(p.x+halfdist)-halfdist;
+float dy=abs(p.y);
+float h=1.-abs(p.x+halfdist*2.)/halfdist/2.;
+float pz=-from.z-(to.z-from.z)*h;
+float l=1.-clamp(max(dx,dy)*width/(pz+dist)*dist*dist,0.,.1)/.1;
+l=pow(abs(l),lineexp)*(1.-pow(clamp(abs(dist-pz)*.45,0.,1.),.5))*4.;
+return normalize(.25+abs(mix(from,to,h)))*l;
+}
+
+mat3 rotmat(vec3 v, float angle)
+{
+	angle=radians(angle);
+	float c = cos(angle);
+	float s = sin(angle);
+	
+	return mat3(c + (1.0 - c) * v.x * v.x, (1.0 - c) * v.x * v.y - s * v.z, (1.0 - c) * v.x * v.z + s * v.y,
+		(1.0 - c) * v.x * v.y + s * v.z, c + (1.0 - c) * v.y * v.y, (1.0 - c) * v.y * v.z - s * v.x,
+		(1.0 - c) * v.x * v.z - s * v.y, (1.0 - c) * v.y * v.z + s * v.x, c + (1.0 - c) * v.z * v.z
+		);
+}
+
+float getz(vec2 xy) {
+xy=xy*10.+hcells;
+//float pos=length(pow(abs(xy/cells),vec2(3.)))*8.;
+float pos=(xy.y*cells.x+xy.x)/(cells.x*cells.y);
+float s=texture(iChannel0,vec2(.5+pos*.5,.1)).x;
+return .25-pow(s,1.5)*height;
+}
+
+void mainImage( out vec4 fragColor, in vec2 fragCoord )
+{
+	vec2 uv = (gl_FragCoord.xy / iResolution.xy-.5)*2.;
+	uv.y*=iResolution.y/iResolution.x;
+	mat3 camrot=rotmat(normalize(vec3(0.,0.,1.)),iTime*25.)*rotmat(normalize(vec3(1.,0.*sin(iTime*.5),0.)),60.+30.*sin(iTime*.5));
+	float s=.1,maxc=0.;
+	vec3 p1,p2,p3;
+	vec3 rotv=vec3(0.,0.,1.);
+	float h;
+	vec3 col=vec3(0.);
+	float dist=1.2+pow(abs(sin(iTime*.3)),5.)*.5;
+	vec3 c=vec3(0.);
+	for (float y=0.; y<cells.y; y++) {
+		for (float x=0.; x<cells.x; x++) {
+			p1=vec3(x-hcells.x,y-hcells.y,0.)*.1; p1.z=getz(p1.xy);
+			p2=vec3(p1.x+.1,p1.y   ,0.); p2.z=getz(p2.xy);
+			p3=vec3(p1.x   ,p1.y+.1,0.); p3.z=getz(p3.xy);
+			p1*=camrot; p2*=camrot; p3*=camrot;
+			p1.xy*=persp/max(0.1,p1.z+dist);
+			p2.xy*=persp/max(0.1,p2.z+dist);
+			p3.xy*=persp/max(0.1,p3.z+dist);
+			if (max(p1.x,p2.x)>uv.x-linewidth/4. && min(p1.x,p2.x)<uv.x+linewidth/4. && x<cells.x-1.) {
+				if (max(p1.y,p2.y)>uv.y-linewidth/4. && min(p1.y,p2.y)<uv.y+linewidth/4.) {
+					#ifdef OPAQUE_MODE
+						c=max(c,segment(uv,p1,p2,linewidth,dist)*1.5);
+					#else
+						c+=segment(uv,p1,p2,linewidth,dist);
+					#endif
+				}
+			}
+			if (max(p1.x,p3.x)>uv.x-linewidth/4. && min(p1.x,p3.x)<uv.x+linewidth/4. && y<cells.y-1.) {
+				if (max(p1.y,p3.y)>uv.y-linewidth/4. && min(p1.y,p3.y)<uv.y+linewidth/4.) {
+					#ifdef OPAQUE_MODE
+						c=max(c,segment(uv,p1,p3,linewidth,dist)*1.5);
+					#else
+						c+=segment(uv,p1,p3,linewidth,dist);
+					#endif
+				}
+			}
+		}
+	}
+	c*=brightness;
+#ifdef INVERSE
+	fragColor = vec4(1.-c,1.);
+#else
+	fragColor = vec4(c,1.);
+#endif
+}

shaders/osci.frag

@@ -0,0 +1,40 @@
+// Created by inigo quilez - iq/2013
+// https://www.youtube.com/c/InigoQuilez
+// https://iquilezles.org/
+
+
+// See also:
+//
+// Input - Keyboard    : https://www.shadertoy.com/view/lsXGzf
+// Input - Microphone  : https://www.shadertoy.com/view/llSGDh
+// Input - Mouse       : https://www.shadertoy.com/view/Mss3zH
+// Input - Sound       : https://www.shadertoy.com/view/Xds3Rr
+// Input - SoundCloud  : https://www.shadertoy.com/view/MsdGzn
+// Input - Time        : https://www.shadertoy.com/view/lsXGz8
+// Input - TimeDelta   : https://www.shadertoy.com/view/lsKGWV
+// Inout - 3D Texture  : https://www.shadertoy.com/view/4llcR4
+
+
+void mainImage( out vec4 fragColor, in vec2 fragCoord )
+{
+	// create pixel coordinates
+	vec2 uv = fragCoord.xy / iResolution.xy;
+
+	// the sound texture is 512x2
+	int tx = int(uv.x * 512.0);
+
+	// first row is frequency data (48Khz/4 in 512 texels, meaning 23 Hz per texel)
+	float fft  = texelFetch( iChannel0, ivec2(tx,0), 0 ).x;
+
+	// second row is the sound wave, one texel is one mono sample
+	float wave = texelFetch( iChannel0, ivec2(tx,1), 0 ).x;
+
+	// convert frequency to colors
+	vec3 col = vec3( fft, 4.0*fft*(1.0-fft), 1.0-fft ) * fft;
+
+	// add wave form on top
+	col += 1.0 -  smoothstep(0.0, 0.15, abs(wave - uv.y));
+
+	// output final color
+	fragColor = vec4(col,1.0);
+}

shaders/spectrum.frag

@@ -0,0 +1,38 @@
+/*
+2D LED Spectrum - Visualiser
+Based on Led Spectrum Analyser by: simesgreen - 27th February, 2013 https://www.shadertoy.com/view/Msl3zr
+2D LED Spectrum by: uNiversal - 27th May, 2015
+Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
+*/
+
+void mainImage( out vec4 fragColor, in vec2 fragCoord )
+{
+    // create pixel coordinates
+    vec2 uv = fragCoord.xy / iResolution.xy;
+
+    // quantize coordinates
+    const float bands = 30.0;
+    const float segs = 40.0;
+    vec2 p;
+    p.x = floor(uv.x*bands)/bands;
+    p.y = floor(uv.y*segs)/segs;
+
+    // read frequency data from first row of texture
+    float fft  = texture( iChannel0, vec2(p.x,0.0) ).x;
+
+    // led color
+    vec3 color = mix(vec3(0.0, 2.0, 0.0), vec3(2.0, 0.0, 0.0), sqrt(uv.y));
+
+    // mask for bar graph
+    float mask = (p.y < fft) ? 1.0 : 0.1;
+
+    // led shape
+    vec2 d = fract((uv - p) *vec2(bands, segs)) - 0.5;
+    float led = smoothstep(0.5, 0.35, abs(d.x)) *
+                smoothstep(0.5, 0.35, abs(d.y));
+    vec3 ledColor = led*color*mask;
+
+    // output final color
+    fragColor = vec4(ledColor, 1.0);
+}
+