From 0a359a7508a0117b055b72bcb7dc42ddcb2ed5f9 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 30 Oct 2021 23:29:48 +0300
Subject: [PATCH] Make the Limits struct more robust

---
 source/backends/opengl/deviceinfo_backend.cpp | 21 +++++++++++++------
 source/core/deviceinfo.h                      | 14 ++++++-------
 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/source/backends/opengl/deviceinfo_backend.cpp b/source/backends/opengl/deviceinfo_backend.cpp
index 7e1f3f48..30eeb032 100644
--- a/source/backends/opengl/deviceinfo_backend.cpp
+++ b/source/backends/opengl/deviceinfo_backend.cpp
@@ -6,6 +6,7 @@
 #include <msp/gl/extensions/arb_uniform_buffer_object.h>
 #include <msp/gl/extensions/arb_vertex_shader.h>
 #include <msp/gl/extensions/ext_framebuffer_multisample.h>
+#include <msp/gl/extensions/ext_framebuffer_object.h>
 #include <msp/gl/extensions/ext_gpu_shader4.h>
 #include <msp/gl/extensions/ext_texture_array.h>
 #include <msp/gl/extensions/msp_clipping.h>
@@ -18,13 +19,21 @@ namespace GL {
 
 Limits::Limits()
 {
-	glGetIntegerv(GL_MAX_VERTEX_ATTRIBS, reinterpret_cast<int *>(&max_vertex_attributes));
-	glGetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, reinterpret_cast<int *>(&max_texture_bindings));
-	glGetIntegerv(GL_MAX_UNIFORM_BUFFER_BINDINGS, reinterpret_cast<int *>(&max_uniform_bindings));
 	glGetIntegerv(GL_MAX_CLIP_PLANES, reinterpret_cast<int *>(&max_clip_planes));
-	glGetIntegerv(GL_MAX_SAMPLES, reinterpret_cast<int *>(&max_samples));
-	glGetIntegerv(GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT, reinterpret_cast<int *>(&uniform_buffer_alignment));
-	glGetIntegerv(GL_MAX_COLOR_ATTACHMENTS, reinterpret_cast<int *>(&max_color_attachments));
+	if(ARB_vertex_shader)
+	{
+		glGetIntegerv(GL_MAX_VERTEX_ATTRIBS, reinterpret_cast<int *>(&max_vertex_attributes));
+		glGetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, reinterpret_cast<int *>(&max_texture_bindings));
+	}
+	if(EXT_framebuffer_object)
+		glGetIntegerv(GL_MAX_COLOR_ATTACHMENTS, reinterpret_cast<int *>(&max_color_attachments));
+	if(EXT_framebuffer_multisample)
+		glGetIntegerv(GL_MAX_SAMPLES, reinterpret_cast<int *>(&max_samples));
+	if(ARB_uniform_buffer_object)
+	{
+		glGetIntegerv(GL_MAX_UNIFORM_BUFFER_BINDINGS, reinterpret_cast<int *>(&max_uniform_bindings));
+		glGetIntegerv(GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT, reinterpret_cast<int *>(&uniform_buffer_alignment));
+	}
 }
 
 
diff --git a/source/core/deviceinfo.h b/source/core/deviceinfo.h
index e121a8ca..6ac75ca1 100644
--- a/source/core/deviceinfo.h
+++ b/source/core/deviceinfo.h
@@ -11,13 +11,13 @@ Contains information about various limits imposed by the graphics device.
 */
 struct Limits
 {
-	unsigned max_vertex_attributes;
-	unsigned max_texture_bindings;
-	unsigned max_uniform_bindings;
-	unsigned max_clip_planes;
-	unsigned max_samples;
-	unsigned uniform_buffer_alignment;
-	unsigned max_color_attachments;
+	unsigned max_clip_planes = 6;
+	unsigned max_vertex_attributes = 16;
+	unsigned max_texture_bindings = 16;
+	unsigned max_color_attachments = 8;
+	unsigned max_samples = 4;
+	unsigned max_uniform_bindings = 24;
+	unsigned uniform_buffer_alignment = 256;
 
 	Limits();
 };
-- 
2.43.0