From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 10 Oct 2022 07:27:37 +0000 (+0300)
Subject: Add a falling raindrops effect to forest pond
X-Git-Url: https://git.tdb.fi/?a=commitdiff_plain;h=6a4cf0e1a965ab068439e5f5dd6caa8ffec71abf;p=libs%2Fgl.git

Add a falling raindrops effect to forest pond
---

diff --git a/demos/forestpond/data/exported/Forest.seq b/demos/forestpond/data/exported/Forest.seq
index 9acebd35..10faa52e 100644
--- a/demos/forestpond/data/exported/Forest.seq
+++ b/demos/forestpond/data/exported/Forest.seq
@@ -52,6 +52,15 @@ step "" "shadow_map"
 	depth_test LEQUAL;
 	lighting "Forest.lightn";
 };
+step "blended" "shadow_map"
+{
+	depth_test
+	{
+		compare LEQUAL;
+		write false;
+	};
+	lighting "Forest.lightn";
+};
 postprocessor
 {
 	type ambient_occlusion;
diff --git a/demos/forestpond/data/exported/Forest_environment.seq b/demos/forestpond/data/exported/Forest_environment.seq
index 84cb4565..19517389 100644
--- a/demos/forestpond/data/exported/Forest_environment.seq
+++ b/demos/forestpond/data/exported/Forest_environment.seq
@@ -9,3 +9,12 @@ step "" "content"
 	depth_test LEQUAL;
 	lighting "Forest.lightn";
 };
+step "blended" "content"
+{
+	depth_test
+	{
+		compare LEQUAL;
+		write false;
+	};
+	lighting "Forest.lightn";
+};
diff --git a/demos/forestpond/data/rain.glsl b/demos/forestpond/data/rain.glsl
new file mode 100644
index 00000000..7008498a
--- /dev/null
+++ b/demos/forestpond/data/rain.glsl
@@ -0,0 +1,32 @@
+import msp_interface;
+import shadow;
+
+uniform Rain
+{
+	vec4 rain_color;
+};
+
+uniform DynamicParams
+{
+	float time;
+};
+
+#pragma MSP stage(vertex)
+void main()
+{
+	vec4 vpos = vertex;
+	vpos.z = vpos.z-fract(time/2.5)*20.0;
+	if(vpos.z<0.0)
+		vpos.z += 20.0;
+	out vec4 world_vertex = world_obj_matrix*vpos;
+	gl_Position = clip_eye_matrix*eye_world_matrix*world_vertex;
+	passthrough;
+}
+
+#pragma MSP stage(fragment)
+layout(location=0) out vec4 frag_color;
+void main()
+{
+	float shadow = get_shadow_factor(0, world_vertex);
+	frag_color = rain_color*vec4(vec3(0.5+0.5*shadow), texcoord.x);
+}
diff --git a/demos/forestpond/data/rain.shader b/demos/forestpond/data/rain.shader
new file mode 100644
index 00000000..8fe015b5
--- /dev/null
+++ b/demos/forestpond/data/rain.shader
@@ -0,0 +1,4 @@
+module "rain.glsl"
+{
+	specialize "use_shadow_map" true;
+};
diff --git a/demos/forestpond/data/rain.tech b/demos/forestpond/data/rain.tech
new file mode 100644
index 00000000..330d37b5
--- /dev/null
+++ b/demos/forestpond/data/rain.tech
@@ -0,0 +1,9 @@
+method "blended"
+{
+	shader "rain.shader";
+	uniforms
+	{
+		uniform "rain_color" 0.5 0.5 0.5 0.5;
+	};
+	blend SRC_ALPHA ONE_MINUS_SRC_ALPHA;
+};
diff --git a/demos/forestpond/source/forestpond.cpp b/demos/forestpond/source/forestpond.cpp
index d1a0d032..bbe1f7b0 100644
--- a/demos/forestpond/source/forestpond.cpp
+++ b/demos/forestpond/source/forestpond.cpp
@@ -13,7 +13,8 @@ ForestPond::ForestPond(int, char **):
 	resources(nullptr),
 	view(window),
 	camera(resources.get<GL::Camera>("Camera.camera")),
-	water(resources.get<GL::Object>("Water.object"), resources, { resources.get<GL::Mesh>("Terrain.mesh"), -10.0f, -3.0f, 2.0f, 6.0f })
+	water(resources.get<GL::Object>("Water.object"), resources, { resources.get<GL::Mesh>("Terrain.mesh"), -10.0f, -3.0f, 2.0f, 6.0f }),
+	rain(resources, 3000, { -1.5f, -3.0f }, 10.0f)
 {
 	window.set_title("Forest Pond");
 	window.signal_close.connect(sigc::bind(sigc::mem_fun(this, &ForestPond::exit), 0));
@@ -34,6 +35,7 @@ ForestPond::ForestPond(int, char **):
 
 	content.add(resources.get<GL::Scene>("Forest.scene"));
 	content.add(*env_map);
+	content.add(rain);
 	water.set_matrix(GL::Matrix::translation(GL::Vector3(-3, 2, 0)));
 
 	view.set_content(sequence.get());
diff --git a/demos/forestpond/source/forestpond.h b/demos/forestpond/source/forestpond.h
index b22db689..17d94746 100644
--- a/demos/forestpond/source/forestpond.h
+++ b/demos/forestpond/source/forestpond.h
@@ -13,6 +13,7 @@
 #include <msp/gl/windowview.h>
 #include <msp/graphics/display.h>
 #include <msp/graphics/window.h>
+#include "rain.h"
 #include "water.h"
 
 class ForestPond: public Msp::RegisteredApplication<ForestPond>
@@ -39,6 +40,7 @@ private:
 
 	Msp::GL::OrderedScene content;
 	Water water;
+	Rain rain;
 	std::unique_ptr<Msp::GL::Sequence> env_seq;
 	std::unique_ptr<Msp::GL::EnvironmentMap> env_map;
 
diff --git a/demos/forestpond/source/rain.cpp b/demos/forestpond/source/rain.cpp
new file mode 100644
index 00000000..d02e9ef9
--- /dev/null
+++ b/demos/forestpond/source/rain.cpp
@@ -0,0 +1,47 @@
+#include <msp/gl/meshbuilder.h>
+#include <msp/gl/renderer.h>
+#include "rain.h"
+
+using namespace Msp;
+
+Rain::Rain(DataFile::Collection &resources, unsigned count, const LinAl::Vector<float, 2> &center, float radius):
+	tech(resources.get<GL::Technique>("rain.tech")),
+	mesh((GL::VERTEX3, GL::TEXCOORD1))
+{
+	std::minstd_rand rng;
+	std::uniform_real_distribution<float> dist(0.0f, 1.0f);
+	GL::MeshBuilder bld(mesh);
+	bld.begin(GL::LINES);
+	for(unsigned i=0; i<count; ++i)
+	{
+		float r = sqrt(dist(rng))*radius;
+		Geometry::Angle<float> a = Geometry::Angle<float>::from_turns(dist(rng));
+		GL::Vector3 p = compose(center, 0.0f) + GL::Vector3(cos(a)*r, sin(a)*r, i*20.0f/count);
+		bld.texcoord(1.0f);
+		bld.vertex(p);
+		bld.texcoord(0.0f);
+		bld.vertex(p+GL::Vector3(0.0f, 0.0f, 0.2f));
+	}
+	bld.end();
+
+	shdata.uniform("time", 0.0f);
+}
+
+void Rain::setup_frame(GL::Renderer &)
+{
+	time += 0.016f;
+	shdata.uniform("time", time);
+}
+
+void Rain::render(GL::Renderer &renderer, GL::Tag tag) const
+{
+	const GL::RenderMethod *method = tech.find_method(tag);
+	if(!method)
+		return;
+
+	GL::Renderer::Push _push(renderer);
+
+	method->apply(renderer);
+	renderer.add_shader_data(shdata);
+	mesh.draw(renderer);
+}
diff --git a/demos/forestpond/source/rain.h b/demos/forestpond/source/rain.h
new file mode 100644
index 00000000..fd38bea4
--- /dev/null
+++ b/demos/forestpond/source/rain.h
@@ -0,0 +1,25 @@
+#ifndef RAIN_H_
+#define RAIN_H_
+
+#include <random>
+#include <msp/datafile/collection.h>
+#include <msp/gl/mesh.h>
+#include <msp/gl/renderable.h>
+#include <msp/gl/technique.h>
+
+class Rain: public Msp::GL::Renderable
+{
+private:
+	const Msp::GL::Technique &tech;
+	Msp::GL::Mesh mesh;
+	Msp::GL::ProgramData shdata;
+	float time = 0.0f;
+
+public:
+	Rain(Msp::DataFile::Collection &, unsigned, const Msp::LinAl::Vector<float, 2> &, float);
+
+	void setup_frame(Msp::GL::Renderer &) override;
+	void render(Msp::GL::Renderer &, Msp::GL::Tag) const override;
+};
+
+#endif