6 files changed, 44 insertions, 16 deletions
diff --git a/source/blender/gpu/intern/gpu_select.c b/source/blender/gpu/intern/gpu_select.c
index aadb52fb49c..958aab65b57 100644
--- a/source/blender/gpu/intern/gpu_select.c
+++ b/source/blender/gpu/intern/gpu_select.c
@@ -61,6 +61,15 @@ typedef struct GPUSelectState {
   char algorithm;
   /* allow GPU_select_begin/end without drawing */
   bool use_cache;
+  /**
+   * Signifies that #GPU_select_cache_begin has been called,
+   * future calls to #GPU_select_begin should initialize the cache.
+   *
+   * \note #GPU_select_cache_begin could perform initialization but doesn't as it's inconvenient
+   * for callers making the cache begin/end calls outside lower level selection logic
+   * where the `mode` to pass to #GPU_select_begin yet isn't known.
+   */
+  bool use_cache_needs_init;
 } GPUSelectState;
 
 static GPUSelectState g_select_state = {0};
@@ -90,9 +99,26 @@ void GPU_select_begin(uint *buffer, uint bufsize, const rcti *input, char mode,
     g_select_state.algorithm = ALGO_GL_QUERY;
   }
 
+  /* This function is called when cache has already been initialized,
+   * so only manipulate cache values when cache is pending. */
+  if (g_select_state.use_cache_needs_init) {
+    g_select_state.use_cache_needs_init = false;
+
+    switch (g_select_state.algorithm) {
+      case ALGO_GL_QUERY: {
+        g_select_state.use_cache = false;
+        break;
+      }
+      default: {
+        g_select_state.use_cache = true;
+        gpu_select_pick_cache_begin();
+        break;
+      }
+    }
+  }
+
   switch (g_select_state.algorithm) {
     case ALGO_GL_QUERY: {
-      g_select_state.use_cache = false;
       gpu_select_query_begin((uint(*)[4])buffer, bufsize / 4, input, mode, oldhits);
       break;
     }
@@ -154,12 +180,13 @@ uint GPU_select_end(void)
 
 void GPU_select_cache_begin(void)
 {
-  /* validate on GPU_select_begin, clear if not supported */
-  BLI_assert(g_select_state.use_cache == false);
-  g_select_state.use_cache = true;
-  if (g_select_state.algorithm == ALGO_GL_PICK) {
-    gpu_select_pick_cache_begin();
-  }
+  BLI_assert(g_select_state.select_is_active == false);
+  /* Ensure #GPU_select_cache_end is always called. */
+  BLI_assert(g_select_state.use_cache_needs_init == false);
+
+  /* Signal that cache should be used, instead of calling the algorithms cache-begin function.
+   * This is more convenient as the exact method of selection may not be known by the caller. */
+  g_select_state.use_cache_needs_init = true;
 }
 
 void GPU_select_cache_load_id(void)
@@ -173,9 +200,12 @@ void GPU_select_cache_load_id(void)
 void GPU_select_cache_end(void)
 {
   if (g_select_state.algorithm == ALGO_GL_PICK) {
+    BLI_assert(g_select_state.use_cache == true);
     gpu_select_pick_cache_end();
   }
   g_select_state.use_cache = false;
+  /* Paranoid assignment, should already be false. */
+  g_select_state.use_cache_needs_init = false;
 }
 
 bool GPU_select_is_cached(void)
diff --git a/source/blender/gpu/intern/gpu_select_pick.c b/source/blender/gpu/intern/gpu_select_pick.c
index 737e4c6e874..ddd3dfc6879 100644
--- a/source/blender/gpu/intern/gpu_select_pick.c
+++ b/source/blender/gpu/intern/gpu_select_pick.c
@@ -673,7 +673,7 @@ uint gpu_select_pick_end(void)
 #endif
       /* first 3 are dummy values */
       g_pick_state.buffer[hits][0] = 1;
-      g_pick_state.buffer[hits][1] = 0x0; /* depth_data[i].depth; */ /* unused */
+      g_pick_state.buffer[hits][1] = depth_data[i].depth;
       g_pick_state.buffer[hits][2] = 0x0; /* z-far is currently never used. */
       g_pick_state.buffer[hits][3] = depth_data[i].id;
       hits++;
diff --git a/source/blender/gpu/intern/gpu_shader_create_info.cc b/source/blender/gpu/intern/gpu_shader_create_info.cc
index e245d9b5269..f7622751726 100644
--- a/source/blender/gpu/intern/gpu_shader_create_info.cc
+++ b/source/blender/gpu/intern/gpu_shader_create_info.cc
@@ -112,7 +112,7 @@ void ShaderCreateInfo::finalize()
 void ShaderCreateInfo::validate(const ShaderCreateInfo &other_info)
 {
   {
-    /* Check same bindpoints usage in OGL. */
+    /* Check same bind-points usage in OGL. */
     Set<int> images, samplers, ubos, ssbos;
 
     auto register_resource = [&](const Resource &res) -> bool {
diff --git a/source/blender/gpu/intern/gpu_shader_create_info.hh b/source/blender/gpu/intern/gpu_shader_create_info.hh
index 391752a31a8..6236e92a226 100644
--- a/source/blender/gpu/intern/gpu_shader_create_info.hh
+++ b/source/blender/gpu/intern/gpu_shader_create_info.hh
@@ -63,7 +63,10 @@ enum class Type {
 };
 
 enum class BuiltinBits {
-  /** Allow getting barycentic coordinates inside the fragment shader. NOTE: emulated on OpenGL. */
+  /**
+   * Allow getting barycentric coordinates inside the fragment shader.
+   * \note Emulated on OpenGL.
+   */
   BARYCENTRIC_COORD = (1 << 0),
   FRAG_COORD = (1 << 2),
   FRONT_FACING = (1 << 4),
diff --git a/source/blender/gpu/opengl/gl_backend.cc b/source/blender/gpu/opengl/gl_backend.cc
index c32123bc15e..92d180f1140 100644
--- a/source/blender/gpu/opengl/gl_backend.cc
+++ b/source/blender/gpu/opengl/gl_backend.cc
@@ -423,7 +423,7 @@ static void detect_workarounds()
 
   /* Buggy interface query functions cause crashes when handling SSBOs (T93680) */
   if (GPU_type_matches(GPU_DEVICE_INTEL, GPU_OS_ANY, GPU_DRIVER_ANY) &&
-    (strstr(renderer, "HD Graphics 4400")|| strstr(renderer, "HD Graphics 4600"))) {
+      (strstr(renderer, "HD Graphics 4400") || strstr(renderer, "HD Graphics 4600"))) {
     GCaps.shader_storage_buffer_objects_support = false;
   }
 }  // namespace blender::gpu
diff --git a/source/blender/gpu/opengl/gl_shader.cc b/source/blender/gpu/opengl/gl_shader.cc
index 0d4f1d15f39..1e6e2475665 100644
--- a/source/blender/gpu/opengl/gl_shader.cc
+++ b/source/blender/gpu/opengl/gl_shader.cc
@@ -601,11 +601,6 @@ static char *glsl_patch_default_get()
     STR_CONCAT(patch, slen, "#extension GL_ARB_shading_language_420pack: enable\n");
   }
 
-  if (!GLContext::shader_draw_parameters_support) {
-    /* Fallback: Emulate base instance using a uniform. */
-    STR_CONCAT(patch, slen, "uniform int gpu_BaseInstance;\n");
-  }
-
   /* Fallbacks. */
   if (!GLContext::shader_draw_parameters_support) {
     STR_CONCAT(patch, slen, "uniform int gpu_BaseInstance;\n");