Randomly fill virtual pages, check if sparse residency for 2D images is supported

data/shaders/texturesparseresidency/sparseresidency.frag

@@ -1,29 +1,37 @@
 #version 450
 
-#extension GL_ARB_separate_shader_objects : enable
-#extension GL_ARB_shading_language_420pack : enable
-// Required for the sparse* commands used in this shader
 #extension GL_ARB_sparse_texture2 : enable
+#extension GL_ARB_sparse_texture_clamp : enable
 
 layout (binding = 1) uniform sampler2D samplerColor;
 
 layout (location = 0) in vec2 inUV;
 layout (location = 1) in float inLodBias;
-layout (location = 2) in vec3 inNormal;
-layout (location = 3) in vec3 inViewVec;
-layout (location = 4) in vec3 inLightVec;
 
 layout (location = 0) out vec4 outFragColor;
 
 void main() 
 {
+	vec4 color = vec4(0.0);
+
 	// Get residency code for current texel
-	int residencyCode = sparseTextureARB(samplerColor, inUV, outFragColor, inLodBias);
+	int residencyCode = sparseTextureARB(samplerColor, inUV, color, inLodBias);
+
+//#define MIN_LOD
+#ifdef MIN_LOD
+	// Fetch sparse until we get a valid texel
+	// todo: does not work in SPIR-V with current drivers (will be fixed in a new release)
+	float minLod = 1.0;
+	while (!sparseTexelsResidentARB(residencyCode)) 
+	{
+		residencyCode = sparseTextureClampARB(samplerColor, inUV, minLod, color);
+		minLod += 1.0f;
+	} 
+#endif
 	// Check if texel is resident
 	bool texelResident = sparseTexelsResidentARB(residencyCode);
 
-	vec4 color;
-
+	float lodClamp = 1.0f; 
 	if (texelResident)
 	{
 		color = texture(samplerColor, inUV, inLodBias);

data/shaders/texturesparseresidency/sparseresidency.vert

@@ -17,13 +17,13 @@ layout (binding = 0) uniform UBO
 
 layout (location = 0) out vec2 outUV;
 layout (location = 1) out float outLodBias;
-layout (location = 2) out vec3 outNormal;
-layout (location = 3) out vec3 outViewVec;
-layout (location = 4) out vec3 outLightVec;
+//layout (location = 2) out vec3 outNormal;
+//layout (location = 3) out vec3 outViewVec;
+//layout (location = 4) out vec3 outLightVec;
 
 out gl_PerVertex 
 {
-    vec4 gl_Position;   
+	vec4 gl_Position;   
 };
 
 void main() 
@@ -34,11 +34,12 @@ void main()
 	vec3 worldPos = vec3(ubo.model * vec4(inPos, 1.0));
 
 	gl_Position = ubo.projection * ubo.model * vec4(inPos.xyz, 1.0);
-
-    vec4 pos = ubo.model * vec4(inPos, 1.0);
+	/*
+	vec4 pos = ubo.model * vec4(inPos, 1.0);
 	outNormal = mat3(inverse(transpose(ubo.model))) * inNormal;
 	vec3 lightPos = vec3(0.0);
 	vec3 lPos = mat3(ubo.model) * lightPos.xyz;
-    outLightVec = lPos - pos.xyz;
-    outViewVec = ubo.viewPos.xyz - pos.xyz;		
+	outLightVec = lPos - pos.xyz;
+	outViewVec = ubo.viewPos.xyz - pos.xyz;		
+	*/
 }