working intersection - rotating simplex

simplex/shaders/main.frag

@@ -11,7 +11,9 @@ vec3 hsv2rgb(vec3 c) {
 }
 
 void main() {
-    vec3 hsv = vec3(pos.w/3 + .6, 1, 1);
+    float h = pos.w / 3 + .6;
+    float s = 1;
+    float v = smoothstep(1, -1, pos.z);
 
-    fcolor = vec4(hsv2rgb(hsv), 1);
+    fcolor = vec4(hsv2rgb(vec3(h, s, v)), 1);
 }

simplex/shaders/main.vert

@@ -1,16 +1,11 @@
 #version 440 core
 
-layout(location=0) in vec4 pos4;
+layout(location=0) in ivec4 vInds;
 
-layout(std140, binding=1) uniform Matrices {
-    mat4 model;
-    mat4 view;
-    mat4 proj;
-};
-
-out vec4 pos;
+out ivec4 inds;
 
 void main() {
-    pos = model * pos4;
-    gl_Position = proj * view * vec4(pos.xyz, -pos.w + 2);
+    inds = vInds;
+
+    gl_Position = vec4(0, 0, 0, 1);
 }

simplex/shaders/sect.geom

@@ -0,0 +1,56 @@
+#version 440 core
+
+layout(points) in;
+layout(triangle_strip, max_vertices=48) out;
+
+layout(std430, binding=1) buffer Positions {
+    vec4 verts[];
+};
+
+layout(std140, binding=1) uniform Matrices {
+    mat4 model;
+    mat4 view;
+    mat4 proj;
+};
+
+in ivec4 inds[];
+
+out vec4 pos;
+
+void emit(vec4 v) {
+    pos = v;
+    gl_Position = proj * view * vec4(v.xyz, -v.w + 2);
+    EmitVertex();
+}
+
+void main() {
+    vec4 pos4[4];
+    for(int i = 0; i < 4; ++i) pos4[i] = model * verts[inds[0][i]];
+
+    int lo[4], L = 0;
+    int hi[4], H = 0;
+
+    for(int i = 0; i < 4; ++i) {
+        if (pos4[i].w < 0) {
+            lo[L++] = i;
+        } else {
+            hi[H++] = i;
+        }
+    }
+
+    vec4 sect[4]; int S = 0;
+    for (int l = 0; l < L; ++l) {
+        for (int h = 0; h < H; ++h) {
+            vec4 a = pos4[lo[l]];
+            vec4 b = pos4[hi[h]];
+
+            sect[S++] = (0 - a.w) / (b.w - a.w) * (b-a) + a;
+        }
+    }
+
+    for(int s = 0; s < S; ++s) {
+        emit(sect[s]);
+    }
+
+    EndPrimitive();
+}

simplex/shaders/wire.geom

@@ -0,0 +1,37 @@
+#version 440 core
+
+layout(points) in;
+layout(line_strip, max_vertices=48) out;
+
+layout(std430, binding=1) buffer Positions {
+    vec4 verts[];
+};
+
+layout(std140, binding=1) uniform Matrices {
+    mat4 model;
+    mat4 view;
+    mat4 proj;
+};
+
+in ivec4 inds[];
+
+out vec4 pos;
+
+void emit(vec4 v) {
+    pos = v;
+    gl_Position = proj * view * vec4(v.xyz, -v.w + 2);
+    EmitVertex();
+}
+
+void main() {
+    vec4 pos4[4];
+    for(int i = 0; i < 4; ++i) pos4[i] = model * verts[inds[0][i]];
+
+    for(int i = 0; i < 4; ++i) {
+        for(int j = i + 1; j < 4; ++j) {
+            emit(pos4[i]);
+            emit(pos4[j]);
+            EndPrimitive();
+        }
+    }
+}