per-primitive coloring

vis/shaders/slice/deferred.vs.glsl

@@ -10,8 +10,10 @@ layout(std140, binding=1) uniform Matrices {
 };
 
 layout(location=0) in ivec4 inds;
+layout(location=1) in vec4 col;
 
 out ivec4 vInds;
+out vec4 vCol;
 
 out gl_PerVertex {
     vec4 gl_Position;
@@ -20,6 +22,7 @@ out gl_PerVertex {
 
 void main() {
     vInds = inds;
+    vCol = col;
 
     vec4 pos = view * verts[vInds.x];
     gl_Position = proj * vec4(pos.xyz, 1);

vis/shaders/slice/slice.gm.glsl

@@ -13,8 +13,10 @@ layout(std140, binding=1) uniform Matrices {
 };
 
 in ivec4 vInds[];
+in vec4 vCol[];
 
 out vec4 pos;
+out vec4 col;
 
 out gl_PerVertex {
     vec4 gl_Position;
@@ -26,6 +28,7 @@ float unmix(float u, float v) {
 
 void emit(vec4 v) {
     pos = v;
+    col = vCol[0];
     gl_Position = proj * vec4(v.xyz, 1);
     EmitVertex();
 }

vis/shaders/solid.fs.glsl

@@ -1,12 +1,14 @@
 #version 430
 
-layout(location=2) uniform vec3 c;
+//layout(location=2) uniform vec3 c;
 
 in vec4 pos;
+in vec4 col;
 
 out vec4 color;
 
 void main() {
-    float d = smoothstep(-2, 2, pos.z);
+    color = col;
-    color = vec4(c * d, 1);
+//    float d = smoothstep(-2, 2, pos.z);
+//    color = vec4(c * d, 1);
 }

vis/src/main.cpp

@@ -51,7 +51,7 @@ struct DeferredMesh {
     cgl::vertexarray vao;
     cgl::buffer<Primitive<N>> ibo;
 
-    explicit DeferredMesh(const Mesh<N> &mesh)
+    explicit DeferredMesh(const Mesh<N> &mesh, const cgl::buffer<glm::vec4> &color)
         : ibo(), vao() {
 
         ibo.put(mesh.prims);
@@ -61,6 +61,10 @@ struct DeferredMesh {
                 glEnableVertexAttribArray(0);
                 glVertexAttribIPointer(0, N, GL_INT, 0, nullptr);
             });
+            color.bound(GL_ARRAY_BUFFER, [&]() {
+                glEnableVertexAttribArray(1);
+                glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 0, nullptr);
+            });
         });
     }
 
@@ -153,8 +157,17 @@ void run(GLFWwindow *window) {
     auto wire_data = merge(poly_parts<2>(group));
     DirectMesh<2> wires(GL_LINES, wire_data);
 
-    auto slice_data = merge(poly_parts<4>(group));
+    const auto slice_parts = poly_parts<4>(group);
-    DeferredMesh<4> slices(slice_data);
+    auto slice_data = merge(slice_parts);
+    auto slice_colors = std::vector<glm::vec4>(slice_data.size());
+    for (int i = 0, k = 0; i < slice_parts.size(); ++i) {
+        glm::vec3 color((float) i / (float) (slice_parts.size() - 1));
+        for (int j = 0; j < slice_parts[i].size(); ++j, ++k) {
+            slice_colors[k] = glm::vec4(color, 1);
+        }
+    }
+    cgl::buffer<glm::vec4> slice_colors_buf(slice_colors);
+    DeferredMesh<4> slices(slice_data, slice_colors_buf);
 
     //endregion
 
@@ -176,17 +189,12 @@ void run(GLFWwindow *window) {
         Matrices mats = build(window, st);
         ubo.put(mats);
 
-        const auto wires_dark = glm::vec3(.3, .3, .3);
-        const auto wires_light = wires_dark;
-
         glLineWidth(1.5);
 
-        glProgramUniform3f(solid, 2, 0.9, 0.9, 0.9);
+//        proj_pipe.bound([&]() {
-        proj_pipe.bound([&]() {
+//            wires.draw();
-            wires.draw();
+//        });
-        });
 
-        glProgramUniform3f(solid, 2, 0.9, 0.1, 0.1);
         slice_pipe.bound([&]() {
             slices.draw();
         });