From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 17 Mar 2022 20:04:52 +0000 (+0200)
Subject: Add instancing support to standard shaders and RenderMethod
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=f1e296bb2442dfbea12e7b38a97cc152aa34569c;p=libs%2Fgl.git

Add instancing support to standard shaders and RenderMethod
---

diff --git a/shaderlib/common.glsl b/shaderlib/common.glsl
index 44ef150a..6bac9c37 100644
--- a/shaderlib/common.glsl
+++ b/shaderlib/common.glsl
@@ -10,6 +10,7 @@ layout(set=1) uniform sampler2D normal_map;
 layout(set=0) uniform samplerCube environment_map;
 layout(set=0) uniform samplerCube irradiance_map;
 
+layout(constant_id=auto) const bool use_instancing = false;
 layout(constant_id=auto) const bool use_normal_map = false;
 
 #pragma MSP stage(vertex)
@@ -25,12 +26,18 @@ virtual vec3 get_vertex_normal()
 
 virtual mat4 get_vertex_transform()
 {
-	return world_obj_matrix;
+	if(use_instancing)
+		return transpose(mat4(instance_transform[0], instance_transform[1], instance_transform[2], vec4(0.0, 0.0, 0.0, 1.0)));
+	else
+		return world_obj_matrix;
 }
 
 virtual mat3 get_normal_transform()
 {
-	return world_obj_normal_matrix;
+	if(use_instancing)
+		return transpose(mat3(instance_transform[0].xyz, instance_transform[1].xyz, instance_transform[2].xyz));
+	else
+		return world_obj_normal_matrix;
 }
 
 void standard_transform()
diff --git a/shaderlib/occluder.glsl b/shaderlib/occluder.glsl
index 6d6cd560..a4d876ec 100644
--- a/shaderlib/occluder.glsl
+++ b/shaderlib/occluder.glsl
@@ -8,6 +8,7 @@ layout(set=1) uniform AlphaCutoff
 layout(set=1) uniform sampler2D alpha_map;
 
 layout(constant_id=auto) const bool use_alpha_cutoff = false;
+layout(constant_id=auto) const bool use_instancing = false;
 
 #pragma MSP stage(vertex)
 virtual vec4 get_vertex_position()
@@ -17,7 +18,10 @@ virtual vec4 get_vertex_position()
 
 virtual mat4 get_vertex_transform()
 {
-	return world_obj_matrix;
+	if(use_instancing)
+		return transpose(mat4(instance_transform[0], instance_transform[1], instance_transform[2], vec4(0.0, 0.0, 0.0, 1.0)));
+	else
+		return world_obj_matrix;
 }
 
 virtual void clipping(vec3 eye_vertex)
diff --git a/source/materials/rendermethod.cpp b/source/materials/rendermethod.cpp
index ddbe4f1e..66424856 100644
--- a/source/materials/rendermethod.cpp
+++ b/source/materials/rendermethod.cpp
@@ -34,6 +34,8 @@ void RenderMethod::maybe_create_material_shader()
 		extra_spec["use_shadow_map"] = true;
 	if(image_based_lighting)
 		extra_spec["use_image_based_lighting"] = true;
+	if(instancing)
+		extra_spec["use_instancing"] = true;
 
 	shprog = material->create_compatible_shader(extra_spec);
 
@@ -154,6 +156,7 @@ void RenderMethod::Loader::init_actions()
 	add("face_cull", &RenderMethod::face_cull);
 	add("shader",   &Loader::shader);
 	add("image_based_lighting", &RenderMethod::image_based_lighting);
+	add("instancing", &RenderMethod::instancing);
 	add("material", &Loader::material_inline);
 	add("material", &Loader::material);
 	add("material_slot", &RenderMethod::material_slot);
diff --git a/source/materials/rendermethod.h b/source/materials/rendermethod.h
index 9ac9337f..8fd289fe 100644
--- a/source/materials/rendermethod.h
+++ b/source/materials/rendermethod.h
@@ -89,6 +89,7 @@ private:
 	Blend blend;
 	bool receive_shadows = false;
 	bool image_based_lighting = false;
+	bool instancing = false;
 
 	void maybe_create_material_shader();
 	void set_material_textures();
@@ -126,6 +127,12 @@ public:
 
 	bool get_image_based_lighting() const { return image_based_lighting; }
 
+	/** Toggles instanced rendering.  Only affects shaders created from
+	materials.  Should be used with InstanceArray. */
+	void set_instancing(bool);
+
+	bool get_instancing() const { return instancing; }
+
 	void apply(Renderer &) const;
 
 	void set_debug_name(const std::string &);