instanced point drawing, 3D shading, worldspace point sizes

CMakeLists.txt

@@ -145,7 +145,7 @@ if(pcg32_ADDED)
   target_include_directories(pcg32 INTERFACE "${pcg32_SOURCE_DIR}")
 endif()
 
-CPMAddPackage("gh:wkjarosz/galois#2bf22e85952c8612832838a26baf68ad93beff7a")
+CPMAddPackage("gh:wkjarosz/galois#6105d219a6f26777fc02a1649c2e1d56f6e8e51e")
 if(galois_ADDED)
   message(STATUS "galois++ library added")
   target_include_directories(galois++ INTERFACE "${galois_SOURCE_DIR}/include")

assets/shaders/grid.frag

@@ -1,6 +1,5 @@
 uniform float alpha;
 uniform ivec2 size;
-in vec4       v_position;
 in vec2       v_texcoord;
 
 // The MIT License

assets/shaders/point_instance.frag

@@ -0,0 +1,29 @@
+uniform mat4  mvp;
+uniform mat3  rotation;
+uniform vec3  color;
+uniform float point_size;
+in vec2       v_texcoord;
+
+// taken from https://gist.github.com/romainguy/6415cbf511233c063a1abe691ad4883b
+vec3 Irradiance_SphericalHarmonics(const vec3 n)
+{
+    // Uniform array of 4 vec3 for SH environment lighting
+    // Computed from "Ditch River" (http://www.hdrlabs.com/sibl/archive.html)
+    const vec3 sh0 = vec3(0.754554516862612, 0.748542953903366, 0.790921515418539);
+    const mat3 sh1 = mat3(vec3(-0.188884931542396, -0.277402551592231, -0.377844212327557),
+                          vec3(0.308152705331738, 0.366796330467391, 0.466698181299906),
+                          vec3(-0.083856548007422, 0.092533500963210, 0.322764661032516));
+    return max(sh0 + sh1 * n, 0.0);
+}
+
+void main()
+{
+    float alpha   = 1.0;
+    float radius2 = dot(v_texcoord, v_texcoord);
+    if (radius2 > 1.0)
+        discard;
+    vec3 n       = vec3(v_texcoord, sqrt(1.0 - radius2));
+    vec3 sh      = Irradiance_SphericalHarmonics(n);
+    sh           = mix(mix(sh, vec3(dot(sh, vec3(1.0 / 3.0))), 0.5), vec3(1.0), 0.25);
+    fo_FragColor = vec4(sh * color * alpha, alpha);
+}

assets/shaders/point_instance.vert

@@ -0,0 +1,14 @@
+uniform mat4  mvp;
+uniform mat4  smash;
+uniform mat3  rotation;
+uniform float point_size;
+in vec3       vertices;
+in vec3       center;
+out vec2      v_texcoord;
+
+void main()
+{
+    gl_Position =
+        mvp * (vec4(rotation * (point_size * vertices), 1.0) + vec4((smash * vec4(center - 0.5, 1.0)).xyz, 0.0));
+    v_texcoord = 2.0 * vertices.xy;
+}

include/app.h

@@ -63,14 +63,14 @@ enum CameraType
 
 struct CameraParameters
 {
-    Arcball    arcball;
-    float      persp_factor = 0.0f;
-    float      zoom = 1.0f, view_angle = 30.0f;
-    float      dnear = 0.05f, dfar = 1000.0f;
-    float3     eye         = float3{0.0f, 0.0f, 2.0f};
-    float3     center      = float3{0.0f, 0.0f, 0.0f};
-    float3     up          = float3{0.0f, 1.0f, 0.0f};
-    CameraType camera_type = CAMERA_CURRENT;
+    Arcball                 arcball;
+    float                   persp_factor = 0.0f;
+    float                   zoom = 1.0f, view_angle = 30.0f;
+    float                   dnear = 0.05f, dfar = 1000.0f;
+    static constexpr float3 eye         = float3{0.0f, 0.0f, 2.0f};
+    static constexpr float3 center      = float3{0.0f, 0.0f, 0.0f};
+    static constexpr float3 up          = float3{0.0f, 1.0f, 0.0f};
+    CameraType              camera_type = CAMERA_CURRENT;
 
     float4x4 matrix(float window_aspect) const;
 };
@@ -114,7 +114,7 @@ class SampleViewer
     void populate_point_subset();
     void draw_text(const int2 &pos, const std::string &text, const float4 &col, ImFont *font = nullptr,
                    int align = TextAlign_RIGHT | TextAlign_BOTTOM) const;
-    void draw_points(const float4x4 &mvp, const float3 &color);
+    void draw_points(const float4x4 &mvp, const float4x4 &smash, const float3 &color);
     void draw_trigrid(Shader *shader, const float4x4 &mvp, float alpha, const int2x3 &count);
     void draw_2D_points_and_grid(const float4x4 &mvp, int2 dims, int plotIndex);
     int2 get_draw_range() const;
@@ -126,7 +126,7 @@ class SampleViewer
     int            m_num_dimensions = 3;
     int3           m_dimension{0, 1, 2};
     Array2d<float> m_points, m_subset_points;
-    vector<float3> m_3d_points;
+    vector<float3> m_3d_points, m_2d_points;
     int            m_target_point_count = 256, m_point_count = 256;
     int            m_subset_count = 0;
 
@@ -142,7 +142,7 @@ class SampleViewer
     bool              m_show_1d_projections = false, m_show_point_nums = false, m_show_point_coords = false,
          m_show_coarse_grid = false, m_show_fine_grid = false, m_show_custom_grid = false, m_show_bbox = false;
 
-    Shader *m_point_shader = nullptr, *m_2d_point_shader = nullptr, *m_grid_shader = nullptr;
+    Shader *m_3d_point_shader = nullptr, *m_2d_point_shader = nullptr, *m_grid_shader = nullptr;
 
     int2  m_viewport_pos, m_viewport_pos_GL, m_viewport_size;
     float m_animate_start_time = 0.0f;

include/arcball.h

@@ -113,10 +113,14 @@ struct Arcball
         return true;
     }
 
+    Quatf quat() const
+    {
+        return linalg::qmul(m_incr, m_quat);
+    }
+
     Mat44f matrix() const
     {
-        auto m = linalg::qmat(linalg::qmul(m_incr, m_quat));
-        return {{m.x, 0.f}, {m.y, 0.f}, {m.z, 0.f}, {0.f, 0.f, 0.f, 1.f}};
+        return linalg::rotation_matrix(quat());
     }
 
 private:

include/shader.h

@@ -102,6 +102,13 @@ class Shader
         set_buffer(name, get_type<T>(), 2, shape, vecs.data());
     }
 
+    template <typename T, int M>
+    void set_buffer(const std::string &name, const std::vector<linalg::vec<T, M>> &vecs, size_t offset, size_t count)
+    {
+        size_t shape[3] = {count, M, 1};
+        set_buffer(name, get_type<T>(), 2, shape, &vecs[offset]);
+    }
+
     template <typename T>
     void set_buffer(const std::string &name, const std::vector<T> &data)
     {