From 7f852de673bb687c5721c6a74367278f8ba62f56 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sat, 20 Jan 2024 12:05:53 +0000
Subject: Implement complete network straight part shader

---
 gfx/gl/shaders/network.fs         | 11 +++++++++++
 gfx/gl/shaders/networkStraight.gs | 38 +++++++++++++++++++++++++++++++++++++-
 gfx/gl/shaders/networkStraight.vs |  8 ++++++--
 3 files changed, 54 insertions(+), 3 deletions(-)

(limited to 'gfx')

diff --git a/gfx/gl/shaders/network.fs b/gfx/gl/shaders/network.fs
index d427da2..e7d15b3 100644
--- a/gfx/gl/shaders/network.fs
+++ b/gfx/gl/shaders/network.fs
@@ -1,6 +1,17 @@
 #version 330 core
+#extension GL_ARB_shading_language_420pack : enable
+
+include(`materialOut.glsl')
+in vec3 rposition;
+in vec2 texCoord;
+
+layout(binding = 0) uniform sampler2D texture0;
+uniform ivec3 viewPoint;
 
 void
 main()
 {
+	gPosition = ivec4(viewPoint + rposition, 0);
+	gNormal = vec4(0, 0, 1, 1);
+	gAlbedoSpec = texture(texture0, texCoord);
 }
diff --git a/gfx/gl/shaders/networkStraight.gs b/gfx/gl/shaders/networkStraight.gs
index c2bfe3f..ccd456a 100644
--- a/gfx/gl/shaders/networkStraight.gs
+++ b/gfx/gl/shaders/networkStraight.gs
@@ -1,5 +1,14 @@
 #version 330 core
 
+const float RAIL_HEIGHT = 250;
+const vec3[] profile = vec3[]( //
+		vec3(-1900.F, 0.F, 0.F), //
+		vec3(-608.F, 0.F, RAIL_HEIGHT), //
+		vec3(0, 0.F, RAIL_HEIGHT * .7F), //
+		vec3(608.F, 0.F, RAIL_HEIGHT), //
+		vec3(1900.F, 0.F, 0.F));
+const float[profile.length()] texturePos = float[](0, 0.34, 0.5, 0.65, 1);
+
 flat in ivec3 apos[];
 flat in ivec3 bpos[];
 flat in mat2 rot[];
@@ -7,9 +16,36 @@ flat in float reps[];
 flat in float dist[];
 
 layout(points) in;
-layout(triangle_strip, max_vertices = 20) out;
+layout(triangle_strip, max_vertices = 10) out;
+
+uniform mat4 viewProjection;
+uniform ivec3 viewPoint;
+
+uniform int clipDistance = 5000000;
+uniform int flatDistance = 1000000;
+
+out vec2 texCoord;
+out vec3 rposition;
+
+void
+doEnd(const ivec3 end, int v, float texY)
+{
+	rposition = vec3(rot[0] * profile[v].xy, profile[v].z);
+	ivec3 vpos = end + ivec3(rposition);
+	gl_Position = viewProjection * vec4(vpos - viewPoint, 1);
+	texCoord = vec2(texturePos[v], texY);
+	EmitVertex();
+}
 
 void
 main()
 {
+	if (dist[0] < clipDistance) {
+		int vstep = (dist[0] < flatDistance) ? 1 : profile.length() - 1;
+		for (int v = 0; v < profile.length(); v += vstep) {
+			doEnd(bpos[0], v, reps[0]);
+			doEnd(apos[0], v, 0);
+		}
+		EndPrimitive();
+	}
 }
diff --git a/gfx/gl/shaders/networkStraight.vs b/gfx/gl/shaders/networkStraight.vs
index 025ae8f..a0fa437 100644
--- a/gfx/gl/shaders/networkStraight.vs
+++ b/gfx/gl/shaders/networkStraight.vs
@@ -5,7 +5,7 @@ layout(location = 1) in ivec3 v_bpos;
 layout(location = 2) in mat2 v_rot;
 layout(location = 4) in float v_reps;
 
-uniform mat4 viewProjection;
+uniform ivec3 viewPoint;
 
 flat out ivec3 apos;
 flat out ivec3 bpos;
@@ -16,5 +16,9 @@ flat out float dist;
 void
 main()
 {
-	dist = viewProjection[0][0];
+	apos = v_apos;
+	bpos = v_bpos;
+	rot = v_rot;
+	reps = v_reps;
+	dist = min(distance(viewPoint, v_apos), distance(viewPoint, v_bpos));
 }
-- 
cgit v1.2.3