gl: Move GL_ARB_base_instance check

It's a GLContext feature check, not a GpuRenderer thing.

So put it there.

docs/reference/gtk/running.md

@@ -366,6 +366,9 @@ does not support them.
 `sync`
 :GL_ARB_sync
 
+`base-instance`
+:GL_EXT_base_instance
+
 ### `GDK_VULKAN_DEVICE`
 
 This variable can be set to the index of a Vulkan device to override
@@ -473,9 +476,6 @@ disable certain optimizations of the "ngl" and "vulkan" renderer.
 `mipmap`
 : Avoid creating mipmaps
 
-`gl-baseinstance`
-: Assume no ARB/EXT_base_instance support
-
 The special value `all` can be used to turn on all values. The special
 value `help` can be used to obtain a list of all supported values.
 

gdk/gdkglcontext.c

@@ -108,6 +108,7 @@ static const GdkDebugKey gdk_gl_feature_keys[] = {
   { "unpack-subimage", GDK_GL_FEATURE_UNPACK_SUBIMAGE, "GL_EXT_unpack_subimage" },
   { "half-float", GDK_GL_FEATURE_VERTEX_HALF_FLOAT, "GL_OES_vertex_half_float" },
   { "sync", GDK_GL_FEATURE_SYNC, "GL_ARB_sync" },
+  { "base-instance", GDK_GL_FEATURE_BASE_INSTANCE, "GL_ARB_base_instance" },
 };
 
 typedef struct _GdkGLContextPrivate GdkGLContextPrivate;
@@ -1697,6 +1698,11 @@ gdk_gl_context_check_features (GdkGLContext *context)
       epoxy_has_gl_extension ("GL_APPLE_sync"))
     features |= GDK_GL_FEATURE_SYNC;
 
+  if (gdk_gl_context_check_version (context, "4.2", "9.9") ||
+      epoxy_has_gl_extension ("GL_EXT_base_instance") ||
+      epoxy_has_gl_extension ("GL_ARB_base_instance"))
+    features |= GDK_GL_FEATURE_BASE_INSTANCE;
+
   return features;
 }
 

gdk/gdkglcontextprivate.h

@@ -32,6 +32,7 @@ typedef enum {
   GDK_GL_FEATURE_UNPACK_SUBIMAGE            = 1 << 1,
   GDK_GL_FEATURE_VERTEX_HALF_FLOAT          = 1 << 2,
   GDK_GL_FEATURE_SYNC                       = 1 << 3,
+  GDK_GL_FEATURE_BASE_INSTANCE              = 1 << 4,
 } GdkGLFeatures;
 
 typedef enum {

gsk/gpu/gskgpurenderer.c

@@ -30,8 +30,6 @@ static const GdkDebugKey gsk_gpu_optimization_keys[] = {
   { "blit", GSK_GPU_OPTIMIZE_BLIT, "Use shaders instead of vkCmdBlit()/glBlitFramebuffer()" },
   { "gradients", GSK_GPU_OPTIMIZE_GRADIENTS, "Don't supersample gradients" },
   { "mipmap", GSK_GPU_OPTIMIZE_MIPMAP, "Avoid creating mipmaps" },
-
-  { "gl-baseinstance", GSK_GPU_OPTIMIZE_GL_BASE_INSTANCE, "Assume no ARB/EXT_base_instance support" },
 };
 
 typedef struct _GskGpuRendererPrivate GskGpuRendererPrivate;

gsk/gpu/gskgpushaderop.c

@@ -13,6 +13,8 @@
 #include "gskvulkandeviceprivate.h"
 #endif
 
+#include "gdkglcontextprivate.h"
+
 /* maximum number of ops to merge into one call
  * If this number is too high, the command may take too long
  * causing the driver to kill us.
@@ -191,7 +193,8 @@ gsk_gpu_shader_op_gl_command_n (GskGpuOp          *op,
 
   for (i = 0; i < n_ops; i += max_ops_per_draw)
     {
-      if (gsk_gpu_frame_should_optimize (frame, GSK_GPU_OPTIMIZE_GL_BASE_INSTANCE))
+      if (gdk_gl_context_has_feature (GDK_GL_CONTEXT (gsk_gpu_frame_get_context (frame)),
+                                      GDK_GL_FEATURE_BASE_INSTANCE))
         {
           glDrawArraysInstancedBaseInstance (GL_TRIANGLES,
                                              0,

gsk/gpu/gskgputypesprivate.h

@@ -118,7 +118,5 @@ typedef enum {
   GSK_GPU_OPTIMIZE_BLIT                 = 1 <<  3,
   GSK_GPU_OPTIMIZE_GRADIENTS            = 1 <<  4,
   GSK_GPU_OPTIMIZE_MIPMAP               = 1 <<  5,
-  /* These require hardware support */
-  GSK_GPU_OPTIMIZE_GL_BASE_INSTANCE     = 1 <<  6,
 } GskGpuOptimizations;
 

gsk/gpu/gsknglrenderer.c

@@ -72,11 +72,6 @@ gsk_ngl_renderer_create_context (GskGpuRenderer       *renderer,
    */
   *supported &= ~GSK_GPU_OPTIMIZE_UBER;
 
-  if (!gdk_gl_context_check_version (context, "4.2", "9.9") &&
-      !epoxy_has_gl_extension ("GL_EXT_base_instance") &&
-      !epoxy_has_gl_extension ("GL_ARB_base_instance"))
-    *supported &= ~GSK_GPU_OPTIMIZE_GL_BASE_INSTANCE;
-
   return GDK_DRAW_CONTEXT (context);
 }