add debug info

src/forge.c

@@ -54,12 +54,10 @@ static void init_context(ShaderProgram program, Context *context,
 
   size = program.frag_count * program.sub_type_count;
   context->sub_state = malloc(size * sizeof(unsigned int));
-  memset(context->sub_state, 0, sizeof(&context->sub_state));
 
-  if (params.demo) {
-    for (i = 0; i < size; i++) {
-      context->sub_state[i] = rand_uint(program.sub_variant_count);
-    }
+  for (i = 0; i < size; i++) {
+    context->sub_state[i] =
+        params.demo ? rand_uint(program.sub_variant_count) : 0;
   }
 
   context->seeds = malloc(program.frag_count * sizeof(unsigned int));

src/shaders.c

@@ -299,9 +299,6 @@ static void update_viewport(ShaderProgram program, Context context) {
   // viewport changed
   if (context.width != program.last_width ||
       context.height != program.last_height) {
-    // update viewport
-    glViewport(0, 0, context.width, context.height);
-
     // clean and resize all textures
     for (i = 0; i < program.tex_count; i++) {
       glActiveTexture(GL_TEXTURE0 + i);
@@ -327,12 +324,19 @@ static void use_program(ShaderProgram program, int i, bool output,
   glUseProgram(program.programs[i]);
 
   if (output) {
+    glViewport(0, 0, context.width, context.height);
+
     // use default framebuffer (output)
     glBindFramebuffer(GL_FRAMEBUFFER, 0);
 
     // clear buffer
     glClear(GL_COLOR_BUFFER_BIT);
   } else {
+    glViewport(
+        0, 0,
+        (int)(context.internal_size * (float)context.width / context.height),
+        context.internal_size);
+
     // use memory framebuffer
     glBindFramebuffer(GL_FRAMEBUFFER, program.frame_buffers[i]);
     glDrawBuffer(GL_COLOR_ATTACHMENT0);