From 782344299d402dfc7e4eb038bba876d7455f50f5 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 10 Jan 2016 18:45:06 +0200
Subject: [PATCH] Adjust OccludedScene to be more compatible with OpenGL ES

GL_SAMPLES_PASSED is not available in OpenGL ES so use occlusion_query2
for GL_ANY_SAMPLES_PASSED.  In theory it's possible for an implementation
to support occlusion_query but not the 2 variant; I'll deal with that
case if I ever come across such a combination of hardware and drivers.
---
 extensions/arb_occlusion_query2.glext |  1 +
 source/occludedscene.cpp              | 31 ++++++++-------------------
 2 files changed, 10 insertions(+), 22 deletions(-)
 create mode 100644 extensions/arb_occlusion_query2.glext

diff --git a/extensions/arb_occlusion_query2.glext b/extensions/arb_occlusion_query2.glext
new file mode 100644
index 00000000..74c4d6b5
--- /dev/null
+++ b/extensions/arb_occlusion_query2.glext
@@ -0,0 +1 @@
+extension ARB_occlusion_query2
diff --git a/source/occludedscene.cpp b/source/occludedscene.cpp
index 8d05f7c1..3d540a72 100644
--- a/source/occludedscene.cpp
+++ b/source/occludedscene.cpp
@@ -1,38 +1,25 @@
 #include <algorithm>
 #include <msp/gl/extensions/arb_occlusion_query.h>
+#include <msp/gl/extensions/arb_occlusion_query2.h>
 #include "camera.h"
 #include "occludedscene.h"
+#include "programbuilder.h"
 #include "renderer.h"
 #include "sphere.h"
 
 using namespace std;
 
-namespace {
-
-const char vshader[] =
-	"void main()\n"
-	"{\n"
-	"	gl_Position = gl_ProjectionMatrix*gl_ModelViewMatrix*gl_Vertex;\n"
-	"}";
-
-const char fshader[] =
-	"void main()\n"
-	"{\n"
-	"	gl_FragColor = vec4(1.0);\n"
-	"}";
-
-}
-
 namespace Msp {
 namespace GL {
 
 OccludedScene::OccludedScene():
 	bounding_mesh((VERTEX3, NORMAL3)),
-	bounding_shader(vshader, fshader),
+	bounding_shader(ProgramBuilder::StandardFeatures()),
 	occluder_min_size(0.25f),
 	cache_dirty(false)
 {
 	static Require req(ARB_occlusion_query);
+	static Require req2(ARB_occlusion_query2);
 
 	/* Use a slightly larger radius to ensure that all parts of the renderable
 	fit inside the icosahedron */
@@ -149,13 +136,13 @@ void OccludedScene::render(Renderer &renderer, const Tag &tag) const
 		for(OccludedArray::const_iterator i=occluded_cache.begin(); (i!=occluded_cache.end() && i->in_frustum); ++i)
 			if(!i->occluder)
 			{
-				glBeginQuery(GL_SAMPLES_PASSED, i->query);
+				glBeginQuery(GL_ANY_SAMPLES_PASSED, i->query);
 				Renderer::Push push2(renderer);
 				renderer.transform(Matrix(*i->renderable->get_matrix())
 					.translate(i->bounding_sphere->get_center())
 					.scale(i->bounding_sphere->get_radius()));
 				bounding_mesh.draw(renderer);
-				glEndQuery(GL_SAMPLES_PASSED);
+				glEndQuery(GL_ANY_SAMPLES_PASSED);
 			}
 
 		glColorMask(true, true, true, true);
@@ -166,9 +153,9 @@ void OccludedScene::render(Renderer &renderer, const Tag &tag) const
 	for(OccludedArray::const_iterator i=occluded_cache.begin(); (i!=occluded_cache.end() && i->in_frustum); ++i)
 		if(!i->occluder)
 		{
-			int samples_passed;
-			glGetQueryObjectiv(i->query, GL_QUERY_RESULT, &samples_passed);
-			if(samples_passed>0)
+			unsigned any_passed = 0;
+			glGetQueryObjectuiv(i->query, GL_QUERY_RESULT, &any_passed);
+			if(any_passed)
 				renderer.render(*i->renderable, tag);
 		}
 }
-- 
2.43.0