From 859015dce969a0d9ba2bc603d6dbb2685159e393 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 15 Nov 2016 19:09:50 +0200
Subject: [PATCH] Add a builtin module for standard shaders

It doesn't support multiple lights as generating the necessary array
interfaces through a geometry shader turned out to be rather non-trivial.
I plan to add deferred rendering modules with multi-light support later.
---
 Build                     |   9 ++
 scripts/resgen.py         |  41 +++++++
 shaderlib/singlepass.glsl | 247 ++++++++++++++++++++++++++++++++++++++
 source/resources.cpp      |  20 ++-
 source/resources.h        |   5 +
 5 files changed, 321 insertions(+), 1 deletion(-)
 create mode 100755 scripts/resgen.py
 create mode 100644 shaderlib/singlepass.glsl

diff --git a/Build b/Build
index ca380f31..fcdb6328 100644
--- a/Build
+++ b/Build
@@ -29,15 +29,24 @@ package "mspgl"
 		};
 	};
 
+	generate "RES"
+	{
+		in_suffix ".glsl";
+		out_suffix ".cpp";
+		command "scripts/resgen.py";
+	};
+
 	library "mspgl"
 	{
 		source "source";
 		source "extensions";
+		source "shaderlib";
 		install true;
 		install_map
 		{
 			map "source" "include/msp/gl";
 			map "extensions" "include/msp/gl/extensions";
+			map "shaderlib" "include/msp/gl/resources";
 		};
 	};
 
diff --git a/scripts/resgen.py b/scripts/resgen.py
new file mode 100755
index 00000000..16cfbfb9
--- /dev/null
+++ b/scripts/resgen.py
@@ -0,0 +1,41 @@
+#!/usr/bin/python
+
+import sys
+import os
+
+def makename(text):
+	result = ""
+	for c in text:
+		if c.isalnum():
+			result += c
+		else:
+			result += '_'
+	return result
+
+def escape(text):
+	result = ""
+	for c in text:
+		if c=='\t':
+			result += "\\t"
+		elif c=='\n':
+			result += "\\n"
+		elif c=='"':
+			result += "\\\""
+		else:
+			result += c
+	return result
+
+name = makename(os.path.split(sys.argv[1])[1])
+lines = open(sys.argv[1]).readlines()
+out = open(sys.argv[2], "w")
+out.write("""namespace Msp {
+namespace GL {
+""")
+out.write("extern const char {}_data[] =\n".format(name))
+for l in lines:
+	out.write("\t\"{}\"\n".format(escape(l)))
+out.write(""";
+
+} // namespace GL
+} // namespace Msp
+""")
diff --git a/shaderlib/singlepass.glsl b/shaderlib/singlepass.glsl
new file mode 100644
index 00000000..f8940f7d
--- /dev/null
+++ b/shaderlib/singlepass.glsl
@@ -0,0 +1,247 @@
+struct LightSourceParameters
+{
+	vec4 position;
+	vec4 diffuse;
+	vec4 specular;
+};
+
+struct MaterialParameters
+{
+	vec4 ambient;
+	vec4 diffuse;
+	vec4 specular;
+	float shininess;
+};
+
+struct ClipPlane
+{
+	vec4 equation;
+};
+
+uniform mat4 eye_obj_matrix;
+uniform mat3 eye_obj_normal_matrix;
+uniform Transform
+{
+	mat4 projection_matrix;
+};
+
+uniform Material
+{
+	MaterialParameters material;
+	float reflectivity;
+};
+
+const bool use_vertex_color = false;
+
+const bool use_lighting = false;
+const bool use_specular = false;
+const bool use_sky = false;
+const bool use_fog = false;
+uniform Lighting
+{
+	// Declared as an array for compatibility reasons
+	LightSourceParameters light_sources[1];
+	vec4 ambient_color;
+	vec4 sky_color;
+	vec3 eye_sky_dir;
+	float horizon_limit;
+	vec4 fog_color;
+	float fog_density;
+};
+
+const bool use_diffuse_map = false;
+uniform sampler2D diffuse_map;
+
+const bool use_normal_map = false;
+uniform sampler2D normal_map;
+
+const bool use_shadow_map = false;
+uniform sampler2DShadow shadow;
+uniform ShadowMap
+{
+	float shadow_darkness;
+	mat4 shd_eye_matrix;
+};
+
+const bool use_reflection = false;
+const bool use_environment_map = false;
+uniform samplerCube environment;
+uniform EnvMap
+{
+	mat3 env_eye_matrix;
+};
+
+const int max_clip_planes = 0;
+uniform Clipping
+{
+	ClipPlane clip_planes[max_clip_planes];
+};
+
+////// vertex
+in vec4 vertex;
+in vec4 texcoord;
+in vec4 color;
+in vec3 normal;
+in vec3 tangent;
+in vec3 binormal;
+
+vec4 get_vertex_position()
+{
+	return vertex;
+}
+
+vec3 get_vertex_normal()
+{
+	return normal;
+}
+
+void singlepass_transform_and_lighting()
+{
+	out vec4 eye_vertex = eye_obj_matrix*get_vertex_position();
+	gl_Position = projection_matrix*eye_vertex;
+
+	out vec3 eye_normal = eye_obj_normal_matrix*get_vertex_normal();
+	vec3 eye_tangent = eye_obj_normal_matrix*tangent;
+	vec3 eye_binormal = eye_obj_normal_matrix*binormal;
+	out mat3 eye_tbn_matrix = mat3(eye_tangent, eye_binormal, eye_normal);
+
+	out vec3 incident_dir = normalize(eye_vertex.xyz);
+	if(use_normal_map)
+		incident_dir = incident_dir*eye_tbn_matrix;
+
+	vec3 ldir = normalize(light_sources[0].position.xyz-eye_vertex.xyz*light_sources[0].position.w);
+	if(use_normal_map)
+		ldir = ldir*eye_tbn_matrix;
+	out vec3 light_dir = ldir;
+
+	out vec3 tbn_sky_dir = eye_sky_dir*eye_tbn_matrix;
+	out vec3 shadow_coord = (shd_eye_matrix*eye_vertex).xyz;
+	out float fog_coord = eye_vertex.z;
+
+	for(int i=0; i<max_clip_planes; ++i)
+		gl_ClipDistance[i] = dot(eye_vertex, clip_planes[i].equation);
+}
+
+void main()
+{
+	singlepass_transform_and_lighting();
+	passthrough;
+}
+
+////// fragment
+out vec4 frag_color;
+
+vec4 get_diffuse_sample()
+{
+	return texture(diffuse_map, texcoord.xy);
+}
+
+vec3 get_normal_sample()
+{
+	return texture(normal_map, texcoord.xy).xyz*2.0-1.0;
+}
+
+vec3 normal;
+vec4 diffuse_sample;
+
+vec3 singlepass_lighting()
+{
+	float shadow_sample = texture(shadow, shadow_coord);
+	float shadow_intensity = mix(1.0, shadow_sample, shadow_darkness);
+
+	vec3 ambient_light = ambient_color.rgb;
+	if(use_sky)
+	{
+		vec3 sky_dir;
+		if(use_normal_map)
+			sky_dir = tbn_sky_dir;
+		else
+			sky_dir = eye_sky_dir;
+		float skylight_intensity = dot(normal, sky_dir)*0.5+0.5;
+		ambient_light += skylight_intensity*sky_color.rgb;
+	}
+
+	vec3 n_light_dir = normalize(light_dir);
+	float diffuse_intensity = max(dot(normal, n_light_dir), 0.0);
+	if(use_shadow_map)
+		diffuse_intensity *= shadow_intensity;
+	vec3 diffuse_light = diffuse_intensity*light_sources[0].diffuse.rgb;
+
+	vec3 half_vec = normalize(light_dir-incident_dir);
+	float specular_intensity = pow(max(dot(half_vec, normal), 0.0), material.shininess);
+	if(use_shadow_map)
+		specular_intensity *= shadow_intensity;
+	vec3 specular_light = specular_intensity*light_sources[0].specular.rgb;
+
+	vec3 result = material.ambient.rgb*ambient_light+material.diffuse.rgb*diffuse_light;
+	if(use_diffuse_map)
+		result *= diffuse_sample.rgb;
+	if(use_specular)
+		result += material.specular.rgb*specular_light;
+
+	return result;
+}
+
+float singlepass_transparency()
+{
+	float alpha = material.diffuse.a;
+	if(use_diffuse_map)
+		alpha *= diffuse_sample.a;
+	return alpha;
+}
+
+vec3 singlepass_reflection()
+{
+	vec3 reflect_dir = reflect(incident_dir, normal);
+	if(use_normal_map)
+		reflect_dir = eye_tbn_matrix*reflect_dir;
+	vec3 result = vec3(0.0);
+
+	if(use_environment_map)
+		result += texture(environment, env_eye_matrix*reflect_dir).rgb*reflectivity;
+
+	if(use_sky && use_specular)
+	{
+		float reflect_altitude = clamp(dot(reflect_dir, eye_sky_dir)-horizon_limit, -1.0, 0.0);
+		float sky_specular_intensity = pow((1.0-reflect_altitude*reflect_altitude), material.shininess/2.0);
+		result += sky_specular_intensity*sky_color.rgb;
+	}
+
+	return result;
+}
+
+vec4 singlepass_color()
+{
+	vec4 result = vec4(1.0);
+	if(use_vertex_color)
+		result *= color;
+	if(use_diffuse_map)
+		result *= get_diffuse_sample();
+	return result;
+}
+
+void main()
+{
+	if(use_normal_map)
+		normal = get_normal_sample();
+	else
+		normal = normalize(eye_normal);
+
+	diffuse_sample = get_diffuse_sample();
+
+	vec4 final_color;
+	if(use_lighting)
+		final_color = vec4(singlepass_lighting(), singlepass_transparency());
+	else
+		final_color = singlepass_color();
+
+	if(use_reflection)
+		final_color += vec4(singlepass_reflection(), 0.0);
+	if(use_fog)
+	{
+		float fog_value = exp(fog_coord*fog_density);
+		final_color = vec4(mix(fog_color.rgb, final_color.rgb, fog_value), final_color.a);
+	}
+
+	frag_color = final_color;
+}
diff --git a/source/resources.cpp b/source/resources.cpp
index bba69315..48e986ce 100644
--- a/source/resources.cpp
+++ b/source/resources.cpp
@@ -23,6 +23,8 @@ using namespace std;
 namespace Msp {
 namespace GL {
 
+extern const char singlepass_glsl_data[];
+
 Resources::Resources():
 	default_tex_filter(SGIS_generate_mipmap ? LINEAR_MIPMAP_LINEAR : LINEAR),
 	srgb_conversion(false),
@@ -43,6 +45,22 @@ Resources::Resources():
 	add_type<Texture3D>().base<Texture>().suffix(".tex3d").keyword("texture3d");
 	add_type<TextureCube>().base<Texture>().suffix(".texcb").keyword("texture_cube");
 	add_type<Texture2DArray>().base<Texture>().suffix(".tex2da").keyword("texture2d_array");
+
+	add_source(get_builtins());
+}
+
+DataFile::BuiltinSource &Resources::get_builtins()
+{
+	static DataFile::BuiltinSource builtins;
+	bool init_done = false;
+
+	if(!init_done)
+	{
+		builtins.add_object("singlepass.glsl", singlepass_glsl_data);
+		init_done = true;
+	}
+
+	return builtins;
 }
 
 void Resources::set_default_texture_filter(TextureFilter tf)
@@ -117,7 +135,7 @@ Program *Resources::create_program(const string &name)
 	if(RefPtr<IO::Seekable> io = open_from_sources(name))
 	{
 		ProgramCompiler compiler;
-		compiler.compile(*io);
+		compiler.compile(*io, this);
 		RefPtr<Program> program = new Program;
 		compiler.add_shaders(*program);
 		program->link();
diff --git a/source/resources.h b/source/resources.h
index 1f3880aa..838b0229 100644
--- a/source/resources.h
+++ b/source/resources.h
@@ -1,6 +1,7 @@
 #ifndef MSP_GL_RESOURCES_H_
 #define MSP_GL_RESOURCES_H_
 
+#include <msp/datafile/builtinsource.h>
 #include <msp/datafile/collection.h>
 #include "texture.h"
 
@@ -26,6 +27,10 @@ private:
 public:
 	Resources();
 
+private:
+	static DataFile::BuiltinSource &get_builtins();
+
+public:
 	void set_default_texture_filter(TextureFilter);
 
 	/** Enables or disables sRGB conversion.  If enabled, textures and material
-- 
2.43.0