Fix T72467: Crash when using many (>64) images in a shader

Previously this limit was rather high, but with UDIMs it's fairly easy
to reach this many images. Even though this exceeds the texture limit
on most hardware as far as I can tell, it should at least not crash.

The old code uses a fixed array which overflows eventually, this fix
replaces the array with a GSet.

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D6416

source/blender/gpu/intern/gpu_codegen.c

@@ -2131,8 +2131,10 @@ GPUPass *GPU_generate_pass(GPUMaterial *material,
 static int count_active_texture_sampler(GPUShader *shader, char *source)
 {
   char *code = source;
-  int samplers_id[64]; /* Remember this is per stage. */
-  int sampler_len = 0;
+
+  /* Remember this is per stage. */
+  GSet *sampler_ids = BLI_gset_int_new(__func__);
+  int num_samplers = 0;
 
   while ((code = strstr(code, "uniform "))) {
     /* Move past "uniform". */
@@ -2167,22 +2169,16 @@ static int count_active_texture_sampler(GPUShader *shader, char *source)
           continue;
         }
         /* Catch duplicates. */
-        bool is_duplicate = false;
-        for (int i = 0; i < sampler_len; i++) {
-          if (samplers_id[i] == id) {
-            is_duplicate = true;
-          }
-        }
-
-        if (!is_duplicate) {
-          samplers_id[sampler_len] = id;
-          sampler_len++;
+        if (BLI_gset_add(sampler_ids, POINTER_FROM_INT(id))) {
+          num_samplers++;
         }
       }
     }
   }
 
-  return sampler_len;
+  BLI_gset_free(sampler_ids, NULL);
+
+  return num_samplers;
 }
 
 static bool gpu_pass_shader_validate(GPUPass *pass, GPUShader *shader)