7 files changed, 68 insertions, 8 deletions
diff --git a/src/main.cc b/src/main.cc
index 5ac18e1..20d7666 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -14,6 +14,7 @@
 #include "shader/wrap/graphic_shader.h"
 #include "shader/wrap/compute_shader.h"
 
+#include "shader/code/geometry.glsl"
 #include "shader/code/vertex.glsl"
 #include "shader/code/fragment.glsl"
 
@@ -72,7 +73,7 @@ int renderWindow() {
 
 	window.init([&]() {
 		scene_shader = std::make_unique<GraphicShader>(
-			VERTEX_SHADER_CODE, FRAGMENT_SHADER_CODE);
+			VERTEX_SHADER_CODE, GEOMETRY_SHADER_CODE, FRAGMENT_SHADER_CODE);
 
 		lattice_a = std::make_unique<LatticeCellBuffer>(nX, nY);
 		lattice_b = std::make_unique<LatticeCellBuffer>(nX, nY);
diff --git a/src/shader/code/collide.glsl b/src/shader/code/collide.glsl
index 90af535..936ca89 100644
--- a/src/shader/code/collide.glsl
+++ b/src/shader/code/collide.glsl
@@ -13,7 +13,7 @@ uniform uint nY;
 const uint  q     = 9;
 const float omega = 0.6;
 
-const float velocityDisplayScalar = 500.;
+const float displayAmplifier = 50.;
 
 float get(uint x, uint y, int i, int j) {
 	return collideCells[q*nX*y + q*x + (i+1)*3 + j+1];
@@ -24,8 +24,8 @@ void set(uint x, uint y, int i, int j, float v) {
 }
 
 void setFluid(uint x, uint y, vec2 v, float d) {
-	fluidCells[3*nX*y + 3*x + 0] = float(x)-nX/2 + velocityDisplayScalar*v.x;
-	fluidCells[3*nX*y + 3*x + 1] = float(y)-nY/2 + velocityDisplayScalar*v.y;
+	fluidCells[3*nX*y + 3*x + 0] = float(x)-nX/2 + displayAmplifier*v.x;
+	fluidCells[3*nX*y + 3*x + 1] = float(y)-nY/2 + displayAmplifier*v.y;
 	fluidCells[3*nX*y + 3*x + 2] = d;
 }
 
diff --git a/src/shader/code/fragment.glsl b/src/shader/code/fragment.glsl
index 37e18bd..a4121b8 100644
--- a/src/shader/code/fragment.glsl
+++ b/src/shader/code/fragment.glsl
@@ -1,5 +1,10 @@
 static const std::string FRAGMENT_SHADER_CODE = R"(
+#version 430
+
+in  vec3 color;
+out vec4 FragColor;
+
 void main() {
-	gl_FragColor = gl_Color;
+	FragColor = vec4(color.xyz, 0.0);
 }
 )";
diff --git a/src/shader/code/geometry.glsl b/src/shader/code/geometry.glsl
new file mode 100644
index 0000000..6701b41
--- /dev/null
+++ b/src/shader/code/geometry.glsl
@@ -0,0 +1,37 @@
+static const std::string GEOMETRY_SHADER_CODE = R"(
+#version 430
+
+layout (points) in;
+layout (triangle_strip, max_vertices=4) out;
+
+uniform mat4 MVP;
+
+in VS_OUT {
+	vec3 color;
+} gs_in[];
+
+out vec3 color;
+
+vec4 project(vec4 v) {
+	return MVP * v;
+}
+
+void emitSquareAt(vec4 position) {
+	const float size = 0.2;
+
+	gl_Position = project(position + vec4(-size, -size, 0.0, 0.0));
+	EmitVertex();
+	gl_Position = project(position + vec4( size, -size, 0.0, 0.0));
+	EmitVertex();
+	gl_Position = project(position + vec4(-size,  size, 0.0, 0.0));
+	EmitVertex();
+	gl_Position = project(position + vec4( size,  size, 0.0, 0.0));
+	EmitVertex();
+}
+
+void main() {
+	color = gs_in[0].color;
+	emitSquareAt(gl_in[0].gl_Position);
+	EndPrimitive();
+}
+)";
diff --git a/src/shader/code/vertex.glsl b/src/shader/code/vertex.glsl
index 0eccad4..0727708 100644
--- a/src/shader/code/vertex.glsl
+++ b/src/shader/code/vertex.glsl
@@ -1,8 +1,14 @@
 static const std::string VERTEX_SHADER_CODE = R"(
-uniform mat4 MVP;
+#version 430
+
+layout (location=0) in vec3 VertexPosition;
+
+out VS_OUT {
+    vec3 color;
+} vs_out;
 
 void main() {
-	gl_Position = MVP * vec4(gl_Vertex.xy, 0.0, 1.0);
-	gl_FrontColor = gl_Vertex.z * vec4(1., 0., 0., 0.);
+	gl_Position  = vec4(VertexPosition.xy, 0., 1.);
+	vs_out.color = vec3(VertexPosition.z, 0., 0.);
 }
 )";
diff --git a/src/shader/wrap/graphic_shader.cc b/src/shader/wrap/graphic_shader.cc
index 0ed37ff..c891730 100644
--- a/src/shader/wrap/graphic_shader.cc
+++ b/src/shader/wrap/graphic_shader.cc
@@ -15,6 +15,16 @@ GraphicShader::Guard GraphicShader::use() const {
 	return Guard(_id);
 }
 
+GraphicShader::GraphicShader(const std::string& vertex,
+                             const std::string& geometry,
+                             const std::string fragment):
+	_id(glCreateProgram()) {
+	glAttachShader(_id, util::compileShader(vertex, GL_VERTEX_SHADER));
+	glAttachShader(_id, util::compileShader(geometry, GL_GEOMETRY_SHADER));
+	glAttachShader(_id, util::compileShader(fragment, GL_FRAGMENT_SHADER));
+	glLinkProgram(_id);
+}
+
 GraphicShader::GraphicShader(const std::string& vertex, const std::string fragment):
 	_id(glCreateProgram()) {
 	glAttachShader(_id, util::compileShader(vertex, GL_VERTEX_SHADER));
diff --git a/src/shader/wrap/graphic_shader.h b/src/shader/wrap/graphic_shader.h
index 25a5efb..dcae6db 100644
--- a/src/shader/wrap/graphic_shader.h
+++ b/src/shader/wrap/graphic_shader.h
@@ -20,6 +20,7 @@ public:
 
 	Guard use() const;
 
+	GraphicShader(const std::string& vertex, const std::string& geometry, const std::string fragment);
 	GraphicShader(const std::string& vertex, const std::string fragment);
 	~GraphicShader();