From d1d1a4e349f18cd36406f75170dad87fbad2722a Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sat, 20 Jan 2024 13:00:49 +0000
Subject: Common code between straight/curve network geometry shaders

---
 gfx/gl/shaders/networkCommon.glsl | 41 +++++++++++++++++++++++++++++++++++++++
 gfx/gl/shaders/networkCurve.gs    | 10 ++++++++++
 gfx/gl/shaders/networkCurve.vs    | 10 +++++-----
 gfx/gl/shaders/networkStraight.gs | 38 ++----------------------------------
 4 files changed, 58 insertions(+), 41 deletions(-)
 create mode 100644 gfx/gl/shaders/networkCommon.glsl

(limited to 'gfx/gl/shaders')

diff --git a/gfx/gl/shaders/networkCommon.glsl b/gfx/gl/shaders/networkCommon.glsl
new file mode 100644
index 0000000..2639eb1
--- /dev/null
+++ b/gfx/gl/shaders/networkCommon.glsl
@@ -0,0 +1,41 @@
+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);
+
+uniform mat4 viewProjection;
+uniform ivec3 viewPoint;
+
+uniform float clipDistance = 5000000;
+uniform float flatDistance = 1000000;
+
+out vec2 texCoord;
+out vec3 rposition;
+
+void
+doVertex(const ivec3 end, const int v, const float texY, const mat2 rot)
+{
+	rposition = vec3(rot * 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
+doSeg(const float dist, const ivec3 apos, const ivec3 bpos, const float atexY, const float btexY, const mat2 arot,
+		const mat2 brot)
+{
+	if (dist < clipDistance) {
+		int vstep = (dist < flatDistance) ? 1 : profile.length() - 1;
+		for (int v = 0; v < profile.length(); v += vstep) {
+			doVertex(bpos, v, btexY, brot);
+			doVertex(apos, v, atexY, arot);
+		}
+		EndPrimitive();
+	}
+}
diff --git a/gfx/gl/shaders/networkCurve.gs b/gfx/gl/shaders/networkCurve.gs
index cf70b6e..c504df3 100644
--- a/gfx/gl/shaders/networkCurve.gs
+++ b/gfx/gl/shaders/networkCurve.gs
@@ -1,9 +1,19 @@
 #version 330 core
 
+flat in ivec3 apos[];
+flat in ivec3 bpos[];
+flat in ivec3 cpos[];
+flat in float reps[];
+
 layout(points) in;
 layout(triangle_strip, max_vertices = 255) out;
 
+const mat2 rot = mat2(1);
+
+include(`networkCommon.glsl')
+
 void
 main()
 {
+	doSeg(0, apos[0], bpos[0], 0.f, reps[0], rot, rot);
 }
diff --git a/gfx/gl/shaders/networkCurve.vs b/gfx/gl/shaders/networkCurve.vs
index b4324d6..d083765 100644
--- a/gfx/gl/shaders/networkCurve.vs
+++ b/gfx/gl/shaders/networkCurve.vs
@@ -5,16 +5,16 @@ layout(location = 1) in ivec3 v_bpos;
 layout(location = 2) in ivec3 v_centre;
 layout(location = 3) in float v_reps;
 
-uniform mat4 viewProjection;
-
 flat out ivec3 apos;
 flat out ivec3 bpos;
-flat out mat2 rot;
+flat out ivec3 cpos;
 flat out float reps;
-flat out float dist;
 
 void
 main()
 {
-	dist = viewProjection[0][0];
+	apos = v_apos;
+	bpos = v_bpos;
+	cpos = v_centre;
+	reps = v_reps;
 }
diff --git a/gfx/gl/shaders/networkStraight.gs b/gfx/gl/shaders/networkStraight.gs
index ccd456a..51df5fb 100644
--- a/gfx/gl/shaders/networkStraight.gs
+++ b/gfx/gl/shaders/networkStraight.gs
@@ -1,14 +1,5 @@
 #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[];
@@ -17,35 +8,10 @@ flat in float dist[];
 
 layout(points) in;
 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();
-}
+include(`networkCommon.glsl')
 
 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();
-	}
+	doSeg(dist[0], apos[0], bpos[0], 0.f, reps[0], rot[0], rot[0]);
 }
-- 
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