diff --git a/config/forge.cfg b/config/forge.cfg
index d61a46e..92c673e 100644
--- a/config/forge.cfg
+++ b/config/forge.cfg
@@ -13,6 +13,9 @@ UNIFORM_SEED_PREFIX=seed
 UNIFORM_STATE_PREFIX=state
 UNIFORM_TEX_PREFIX=tex
 UNIFORM_SRC_PREFIX=midi
+UNIFORM_PAGE=iPage
+UNIFORM_SELECTED=iSelected
+UNIFORM_ACTIVE_PREFIX=active
 
 SUB_TYPE_COUNT=2
 SUB_1_PREFIX=src_
diff --git a/shaders/frag0.glsl b/shaders/frag0.glsl
index 85194f7..517f3b0 100644
--- a/shaders/frag0.glsl
+++ b/shaders/frag0.glsl
@@ -14,6 +14,8 @@ uniform vec2 iTexResolution;
 uniform vec2 iInputResolution1;
 uniform vec2 iInputResolution2;
 uniform int iDemo;
+uniform int iPage;
+uniform int iSelected;
 
 uniform int seed1;
 uniform int seed2;
@@ -28,9 +30,11 @@ uniform int state3;
 uniform int state4;
 uniform int state5;
 uniform int state6;
-uniform int state7;
 uniform int state8;
 
+uniform int active1;
+uniform int active2;
+
 // 2. textures
 // ---------------
 
@@ -1239,10 +1243,6 @@ subroutine(src_stage_sub) vec4 src_16(vec2 vUV, int seed)
 
     // inputs
 
-    int selected = 0; // TODO debug selected
-    int page = 0; // TODO debug page
-    int selected_src = 0; // TODO debug selected
-    int selected_fx = 0; // TODO debug selected
     int selected_srca = state3;
     int selected_srcb = state4;
     int selected_fxa = state5;
@@ -1298,18 +1298,18 @@ subroutine(src_stage_sub) vec4 src_16(vec2 vUV, int seed)
     f += char_at(uv2, vec2(-2.4, -2.55), hex_chars[selected_mfx]);
 
     // show current selected
-    f += selected == 0 ? h_rect(uv2, vec2(-5, 2), vec2(1.2), 0.1) : 0;
-    f += selected == 1 ? h_rect(uv2, vec2(-5, -2), vec2(1.2), 0.1) : 0;
-    f += selected == 2 ? h_rect(uv2, vec2(-2, 2), vec2(1.2), 0.1) : 0;
-    f += selected == 3 ? h_rect(uv2, vec2(5, 0), vec2(1.2), 0.1) : 0;
-    f += selected == 4 ? h_rect(uv2, vec2(-2, -2), vec2(1.2), 0.1) : 0;
+    f += iSelected == 3 ? h_rect(uv2, vec2(-5, 2), vec2(1.2), 0.1) : 0;
+    f += iSelected == 4 ? h_rect(uv2, vec2(-5, -2), vec2(1.2), 0.1) : 0;
+    f += iSelected == 5 ? h_rect(uv2, vec2(-2, 2), vec2(1.2), 0.1) : 0;
+    f += iSelected == 6 ? h_rect(uv2, vec2(5, 0), vec2(1.2), 0.1) : 0;
+    f += iSelected == 8 ? h_rect(uv2, vec2(-2, -2), vec2(1.2), 0.1) : 0;
 
     // show selected src/fx
-    f += selected_src == 0 ? h_rect(uv2, vec2(-5, 0.8), vec2(1, 0), 0.1) : 0;
-    f += selected_src == 1 ? h_rect(uv2, vec2(-5, -3.2), vec2(1, 0), 0.1) : 0;
-    f += selected_fx == 2 ? h_rect(uv2, vec2(-2, 0.8), vec2(1.2, 0), 0.1) : 0;
-    f += selected_fx == 3 ? h_rect(uv2, vec2(5, -1.2), vec2(1, 0), 0.1) : 0;
-    f += selected_fx == 4 ? h_rect(uv2, vec2(-2, -3.2), vec2(1, 0), 0.1) : 0;
+    f += active1 == 1 ? h_rect(uv2, vec2(-5, 0.8), vec2(1, 0), 0.1) : 0;
+    f += active1 == 2 ? h_rect(uv2, vec2(-5, -3.2), vec2(1, 0), 0.1) : 0;
+    f += active2 == 1 ? h_rect(uv2, vec2(-2, 0.8), vec2(1.2, 0), 0.1) : 0;
+    f += active2 == 2 ? h_rect(uv2, vec2(5, -1.2), vec2(1, 0), 0.1) : 0;
+    f += active2 == 3 ? h_rect(uv2, vec2(-2, -3.2), vec2(1, 0), 0.1) : 0;
 
     // show inputs / feedback
     float line_a_a = rect(uv2, vec2(-8, 2), vec2(2, 0.1));
@@ -1334,7 +1334,7 @@ subroutine(src_stage_sub) vec4 src_16(vec2 vUV, int seed)
     }
 
     // show page
-    f += char_at(uv2, vec2(-9.2, -4.3), hex_chars[page]);
+    f += char_at(uv2, vec2(-9.2, -4.3), hex_chars[iPage]);
 
     // show fx values
     f = mix(f, 1 - f, rect(uv2, vec2(-2, 1.1 + 0.9 * fxa_value), vec2(0.9, 0.9 * fxa_value)));
diff --git a/src/forge.c b/src/forge.c
index be6923a..da5a2df 100644
--- a/src/forge.c
+++ b/src/forge.c
@@ -67,6 +67,11 @@ static void init_context(Parameters params, unsigned int in_count,
     state_randomize(context, state_config, frag_count);
   }
 
+  memset(context->active, 0, sizeof(context->active));
+
+  context->page = 0;
+  context->selected = 0;
+
   memset(context->seeds, 0, sizeof(context->seeds));
 
   for (i = 0; i < frag_count; i++) {
@@ -285,7 +290,8 @@ void forge_run(Parameters params) {
 
     program = shaders_init(
         fragment_shaders, config, context, inputs, params.video_in_count,
-        state_config.select_page_count * state_config.select_item_count, NULL);
+        state_config.select_page_count * state_config.select_item_count,
+        state_config.src_count, NULL);
   } else {
     window_output = NULL;
   }
@@ -300,7 +306,7 @@ void forge_run(Parameters params) {
     program = shaders_init(
         fragment_shaders, config, context, inputs, params.video_in_count,
         state_config.select_page_count * state_config.select_item_count,
-        window_output != NULL ? &program : NULL);
+        state_config.src_count, window_output != NULL ? &program : NULL);
   } else {
     window_monitor = NULL;
   }
diff --git a/src/shaders.c b/src/shaders.c
index 322514c..a58bb28 100644
--- a/src/shaders.c
+++ b/src/shaders.c
@@ -260,6 +260,12 @@ static void init_single_program(ShaderProgram *program, unsigned int i,
   program->idemo_locations[i] = glGetUniformLocation(
       program->programs[i],
       config_file_get_str(config, "UNIFORM_DEMO", "iDemo"));
+  program->ipage_locations[i] = glGetUniformLocation(
+      program->programs[i],
+      config_file_get_str(config, "UNIFORM_PAGE", "iPage"));
+  program->iselected_locations[i] = glGetUniformLocation(
+      program->programs[i],
+      config_file_get_str(config, "UNIFORM_SELECTED", "iSelected"));
 
   prefix = config_file_get_str(config, "UNIFORM_IN_RESOLUTION_PREFIX",
                                "iInputResolution");
@@ -310,6 +316,13 @@ static void init_single_program(ShaderProgram *program, unsigned int i,
     }
   }
 
+  prefix = config_file_get_str(config, "UNIFORM_ACTIVE_PREFIX", "active");
+  for (j = 0; j < program->active_count; j++) {
+    sprintf(name, "%s%d", prefix, j + 1);
+    program->iactive_locations[i * program->active_count + j] =
+        glGetUniformLocation(program->programs[i], name);
+  }
+
   // create texX uniforms pointer
   prefix = config_file_get_str(config, "UNIFORM_TEX_PREFIX", "tex");
   for (j = 0; j < program->tex_count; j++) {
@@ -337,7 +350,7 @@ ShaderProgram shaders_init(File *fragment_shaders, ConfigFile config,
                            SharedContext *context, VideoCapture *inputs,
                            unsigned int input_count,
                            unsigned int sub_variant_count,
-                           ShaderProgram *previous) {
+                           unsigned int active_count, ShaderProgram *previous) {
   ShaderProgram program;
 
   if (previous == NULL) {
@@ -351,8 +364,9 @@ ShaderProgram shaders_init(File *fragment_shaders, ConfigFile config,
     program.frag_monitor_index =
         config_file_get_int(config, "FRAG_MONITOR", 1) - 1;
     program.sub_type_count = config_file_get_int(config, "SUB_TYPE_COUNT", 0);
-    program.sub_variant_count = sub_variant_count;
     program.in_count = config_file_get_int(config, "IN_COUNT", 0);
+    program.sub_variant_count = sub_variant_count;
+    program.active_count = active_count;
 
     if (program.frag_count > MAX_FRAG) {
       log_error("FRAG_COUNT over %d", MAX_FRAG);
@@ -378,8 +392,8 @@ ShaderProgram shaders_init(File *fragment_shaders, ConfigFile config,
 
     init_vertices(&program);
 
-    log_debug("Error after init: %04x",
-              glGetError()); // TODO check error at each step
+    // log_debug("Error after init: %04x",
+    //           glGetError()); // TODO check error at each step
   } else {
     program = *previous;
   }
@@ -476,9 +490,16 @@ static void use_program(ShaderProgram program, int i, bool output,
   write_uniform_1f(program.itempo_locations[i], context->tempo);
   write_uniform_1i(program.ifps_locations[i], context->fps);
   write_uniform_1i(program.idemo_locations[i], context->demo ? 1 : 0);
+  write_uniform_1i(program.ipage_locations[i], context->page);
+  write_uniform_1i(program.iselected_locations[i], context->page);
   write_uniform_2f(program.ires_locations[i], &resolution);
   write_uniform_2f(program.itexres_locations[i], &tex_resolution);
 
+  for (j = 0; j < program.active_count; j++) {
+    write_uniform_1i(program.iactive_locations[i * program.active_count + j],
+                     context->active[i] + 1);
+  }
+
   for (j = 0; j < program.in_count; j++) {
     in_resolution[0] = context->input_widths[j];
     in_resolution[1] = context->input_heights[j];
diff --git a/src/shaders.h b/src/shaders.h
index 303add6..2e6b6ca 100644
--- a/src/shaders.h
+++ b/src/shaders.h
@@ -7,7 +7,7 @@ ShaderProgram shaders_init(File *fragment_shaders, ConfigFile config,
                            SharedContext *context, VideoCapture *inputs,
                            unsigned int input_count,
                            unsigned int sub_variant_count,
-                           ShaderProgram *previous);
+                           unsigned int active_count, ShaderProgram *previous);
 
 void shaders_update(ShaderProgram program, File *fragment_shaders,
                     unsigned int i);
diff --git a/src/types.h b/src/types.h
index 596b6a2..21cf85a 100644
--- a/src/types.h
+++ b/src/types.h
@@ -14,16 +14,6 @@
 #ifndef TYPES_H
 #define TYPES_H
 
-typedef struct SharedUint {
-  int fd;
-  unsigned int value;
-} SharedUint;
-
-typedef struct SharedBool {
-  int fd;
-  bool value;
-} SharedBool;
-
 typedef struct Parameters {
   bool hot_reload;
   bool output;
@@ -86,6 +76,9 @@ typedef struct ShaderProgram {
   GLuint idemo_locations[ARRAY_SIZE];
   GLuint iseed_locations[ARRAY_SIZE];
   GLuint istate_locations[ARRAY_SIZE];
+  GLuint ipage_locations[ARRAY_SIZE];
+  GLuint iselected_locations[ARRAY_SIZE];
+  GLuint iactive_locations[ARRAY_SIZE];
 
   GLuint vpos_locations[ARRAY_SIZE];
 
@@ -95,6 +88,8 @@ typedef struct ShaderProgram {
   unsigned int sub_variant_count;
   GLuint sub_locations[ARRAY_SIZE];
 
+  unsigned int active_count;
+
   unsigned int in_count;
   EGLDisplay egl_display;
 } ShaderProgram;
@@ -126,6 +121,9 @@ typedef struct SharedContext {
   unsigned int fps;
   float tempo;
   unsigned int state[MAX_FRAG];
+  unsigned int page;
+  unsigned int selected;
+  unsigned int active[ARRAY_SIZE];
   bool demo;
   unsigned int seeds[MAX_FRAG];
   bool monitor;