Custom land and water shaders

Create sandy beaches, snow topped mountains and grassy hills with a single texture, coloured
according to land height by a custom shader.
Also use the land mass mesh with a new water texture and a custom shader to create rather nice
looking water effect with depth, waves and motion.

10 files changed, 130 insertions, 38 deletions

diff --git a/game/terrain.cpp b/game/terrain.cpp
index 83116fc..20c06e8 100644
--- a/game/terrain.cpp
+++ b/game/terrain.cpp
@@ -9,13 +9,10 @@
 #include <gfx/models/mesh.h>
 #include <gfx/models/vertex.hpp>
 #include <glm/glm.hpp>
+#include <maths.h>
 #include <random>
 #include <stb_image.h>
 
-template<unsigned int Comp> class TerrainComp : public Mesh {
-	using Mesh::Mesh;
-};
-
 Terrain::Terrain() : grass {Texture::cachedTexture.get("grass.png")}, water {Texture::cachedTexture.get("water.png")}
 {
 	constexpr auto size {241}; // Vertices
@@ -66,7 +63,6 @@ Terrain::Terrain() : grass {Texture::cachedTexture.get("grass.png")}, water {Tex
 		}
 	}
 	finish(size, size, vertices);
-	addWater(size, size, resolution);
 }
 
 Terrain::Terrain(const std::string & fileName) :
@@ -89,7 +85,6 @@ Terrain::Terrain(const std::string & fileName) :
 	}
 
 	finish(map.width, map.height, vertices);
-	addWater(map.width, map.height, resolution);
 }
 
 void
@@ -125,40 +120,27 @@ Terrain::finish(unsigned int width, unsigned int height, std::vector<Vertex> & v
 			v(width, x, z).normal = -glm::normalize(glm::cross(c - a, d - b));
 		}
 	}
-	meshes.create<TerrainComp<0>>(vertices, indices);
+	meshes.create<Mesh>(vertices, indices);
 }
 
+static const Transform identity {};
+static const auto identityModel {identity.GetModel()};
+
 void
-Terrain::addWater(unsigned int width, unsigned int height, unsigned int resolution)
+Terrain::tick(TickDuration dur)
 {
-	const auto verticesCount {0U};
-	std::vector<Vertex> vertices;
-	std::vector<unsigned int> indices;
-	// Add water
-	const auto extentx {(int)((width - 1) * resolution / 2)};
-	const auto extentz {(int)((height - 1) * resolution / 2)};
-	vertices.emplace_back(glm::vec3 {-extentx, 0, -extentz}, glm::vec2 {0, 0}, glm::vec3 {0, 1, 0});
-	vertices.emplace_back(glm::vec3 {-extentx, 0, extentz}, glm::vec2 {0, height}, glm::vec3 {0, 1, 0});
-	vertices.emplace_back(glm::vec3 {extentx, 0, extentz}, glm::vec2 {width, height}, glm::vec3 {0, 1, 0});
-	vertices.emplace_back(glm::vec3 {extentx, 0, -extentz}, glm::vec2 {width, 0}, glm::vec3 {0, 1, 0});
-	indices.push_back(verticesCount);
-	indices.push_back(verticesCount + 1);
-	indices.push_back(verticesCount + 2);
-	indices.push_back(verticesCount);
-	indices.push_back(verticesCount + 2);
-	indices.push_back(verticesCount + 3);
-	meshes.create<TerrainComp<1>>(vertices, indices);
+	waveCycle += dur.count();
 }
 
-static const Transform identity {};
-static const auto identityModel {identity.GetModel()};
-
 void
 Terrain::render(const Shader & shader) const
 {
-	shader.setModel(identityModel);
+	shader.setModel(identityModel, Shader::Program::LandMass);
 	grass->Bind();
-	meshes.apply<TerrainComp<0>>(&Mesh::Draw);
+	meshes.apply(&Mesh::Draw);
+
+	shader.setModel(identityModel, Shader::Program::Water);
+	shader.setUniform("waves", {waveCycle, 0, 0});
 	water->Bind();
-	meshes.apply<TerrainComp<1>>(&Mesh::Draw);
+	meshes.apply(&Mesh::Draw);
 }
diff --git a/game/terrain.h b/game/terrain.h
index 1aed1c5..2cec963 100644
--- a/game/terrain.h
+++ b/game/terrain.h
@@ -20,13 +20,13 @@ public:
 
 	void render(const Shader & shader) const override;
 
-	void tick(TickDuration) override { }
+	void tick(TickDuration) override;
+	float waveCycle {0.F};
 
 private:
 	static constexpr unsigned int NUM_BUFFERS {4};
 
 	void finish(unsigned int width, unsigned int height, std::vector<Vertex> &);
-	void addWater(unsigned int width, unsigned int height, unsigned int resolution);
 
 	Collection<Mesh, false> meshes;
 	std::shared_ptr<Texture> grass, water;
diff --git a/gfx/gl/shader.cpp b/gfx/gl/shader.cpp
index 8c58c39..454ad4b 100644
--- a/gfx/gl/shader.cpp
+++ b/gfx/gl/shader.cpp
@@ -1,7 +1,11 @@
 #include "shader.h"

 #include <array>

 #include <gfx/gl/shaders/fs-basicShader.h>

+#include <gfx/gl/shaders/fs-landmassShader.h>

+#include <gfx/gl/shaders/fs-waterShader.h>

 #include <gfx/gl/shaders/vs-basicShader.h>

+#include <gfx/gl/shaders/vs-landmassShader.h>

+#include <gfx/gl/shaders/vs-waterShader.h>

 #include <glm/glm.hpp>

 #include <stdexcept>

 #include <string>

@@ -28,9 +32,17 @@ Shader::ProgramHandle::ProgramHandle(std::initializer_list<GLuint> srcs) : viewP
 

 Shader::Shader() :

 	programs {{{

-			Source {{basicShader_vs, basicShader_vs_len}, GL_VERTEX_SHADER}.id,

-			Source {{basicShader_fs, basicShader_fs_len}, GL_FRAGMENT_SHADER}.id,

-	}}}

+					   Source {{basicShader_vs, basicShader_vs_len}, GL_VERTEX_SHADER}.id,

+					   Source {{basicShader_fs, basicShader_fs_len}, GL_FRAGMENT_SHADER}.id,

+			   },

+			{

+					Source {{waterShader_vs, waterShader_vs_len}, GL_VERTEX_SHADER}.id,

+					Source {{waterShader_fs, waterShader_fs_len}, GL_FRAGMENT_SHADER}.id,

+			},

+			{

+					Source {{landmassShader_vs, landmassShader_vs_len}, GL_VERTEX_SHADER}.id,

+					Source {{landmassShader_fs, landmassShader_fs_len}, GL_FRAGMENT_SHADER}.id,

+			}}}

 {

 }

 

diff --git a/gfx/gl/shader.h b/gfx/gl/shader.h
index 0282f21..5d26781 100644
--- a/gfx/gl/shader.h
+++ b/gfx/gl/shader.h
@@ -9,7 +9,7 @@
 

 class Shader {

 public:

-	enum class Program { Basic = 0 };

+	enum class Program { Basic = 0, Water = 1, LandMass = 2 };

 

 	Shader();

 

@@ -39,7 +39,7 @@ private:
 		GLint viewProjection_uniform, model_uniform;

 	};

 

-	std::array<ProgramHandle, 1> programs;

+	std::array<ProgramHandle, 3> programs;

 };

 

 #endif

diff --git a/gfx/gl/shaders/landmassShader.fs b/gfx/gl/shaders/landmassShader.fs
new file mode 100644
index 0000000..36cc971
--- /dev/null
+++ b/gfx/gl/shaders/landmassShader.fs
@@ -0,0 +1,41 @@
+#version 130

+

+in vec2 texCoord0;

+in vec3 normal0;

+in float height;

+

+uniform sampler2D sampler;

+uniform vec3 lightDirection;

+uniform vec3 lightColor;

+uniform vec3 ambientColor;

+

+const vec3 grass = vec3(.1, .4, .05);

+const vec3 sand = vec3(.76, .7, .5);

+const vec3 snow = vec3(.97, .97, .99);

+

+vec2

+grad_between(float x, float lower, float upper)

+{

+	float off = (x - lower) / (upper - lower);

+	return vec2(off, 1 - off);

+}

+

+void

+main()

+{

+	gl_FragColor = texture(sampler, texCoord0);

+	gl_FragColor.xyz *= clamp(ambientColor + (dot(-lightDirection, normal0) * lightColor), 0.0, 1.0);

+	if (height < 0.5) {

+		gl_FragColor.rgb *= sand;

+	}

+	else if (height > 30) {

+		gl_FragColor.rgb *= snow;

+	}

+	else if (height > 28) {

+		vec2 grad = grad_between(height, 28, 30);

+		gl_FragColor.rgb *= grass + (snow - grass) * grad.x;

+	}

+	else {

+		gl_FragColor.rgb *= grass;

+	}

+}

diff --git a/gfx/gl/shaders/landmassShader.vs b/gfx/gl/shaders/landmassShader.vs
new file mode 100644
index 0000000..72c9060
--- /dev/null
+++ b/gfx/gl/shaders/landmassShader.vs
@@ -0,0 +1,21 @@
+#version 130

+

+in vec3 position;

+in vec2 texCoord;

+in vec3 normal;

+

+out vec2 texCoord0;

+out vec3 normal0;

+out float height;

+

+uniform mat4 viewProjection;

+uniform mat4 model;

+uniform vec3 waves;

+

+void main()

+{

+	gl_Position = viewProjection * model * vec4(position, 1.0);

+	texCoord0 = texCoord;

+	normal0 = normal;

+	height = position.y;

+}

diff --git a/gfx/gl/shaders/waterShader.fs b/gfx/gl/shaders/waterShader.fs
new file mode 100644
index 0000000..bdfbc33
--- /dev/null
+++ b/gfx/gl/shaders/waterShader.fs
@@ -0,0 +1,13 @@
+#version 130

+

+in vec2 texCoord0;

+in float depth;

+

+uniform sampler2D sampler;

+uniform vec3 waves;

+

+void main()

+{

+	gl_FragColor = texture(sampler, texCoord0);

+	gl_FragColor.a *= clamp(-depth * .7, .1, 1.0);

+}

diff --git a/gfx/gl/shaders/waterShader.vs b/gfx/gl/shaders/waterShader.vs
new file mode 100644
index 0000000..55a0fb8
--- /dev/null
+++ b/gfx/gl/shaders/waterShader.vs
@@ -0,0 +1,23 @@
+#version 130

+

+in vec3 position;

+in vec2 texCoord;

+in vec3 normal;

+

+out vec2 texCoord0;

+out float depth;

+

+uniform mat4 viewProjection;

+uniform mat4 model;

+uniform vec3 waves;

+

+void main()

+{

+	vec3 wpos = vec3(

+			position.x + cos(waves.x),

+			cos(waves.x + position.x + (position.z / 7)) * .3,

+			position.z + cos(waves.x * waves.z));

+	gl_Position = viewProjection * model * vec4(wpos, 1.0);

+	texCoord0 = texCoord;

+	depth = position.y;

+}

diff --git a/res/grass.png b/res/grass.png
index 9f410e1..2f76277 100644
--- a/res/grass.png
+++ b/res/grass.png
diff --git a/res/water.png b/res/water.png
index ed7a284..4493852 100644
--- a/res/water.png
+++ b/res/water.png