changed plane construction to accept 4 parameters to specify (a,b,c,d) directly (in addition to 6 parameter mode)

git-svn-id: svn://anubis/anaglym/trunk@147 99a6e188-d820-4881-8870-2d33a10e2619

.todo

@@ -1,3 +1,2 @@
-- add plane constructor taking 4 parameters for (a,b,c,d)
 - support loading and applying textures for managed objects
 - debug hooks for loading and execution to halt infinite lua loops

Engine.cc

@@ -31,6 +31,8 @@ using namespace std;
 
 #define WHITESPACE " \t\r\n\f"
 
+#define FP_EQ(a,b) (fabsf(a - b) < 0.0001)
+
 /* Global data */
 Engine * g_engine;
 
@@ -54,6 +56,13 @@ static string trim(const string & orig)
     return result;
 }
 
+static void cross_product(dVector3 result, dVector3 first, dVector3 second)
+{
+    result[0] = first[1] * second[2] - first[2] * second[1];
+    result[1] = first[2] * second[0] - first[0] * second[2];
+    result[2] = first[0] * second[1] - first[1] * second[0];
+}
+
 /******** Engine functions ********/
 
 Engine::Engine(const string & path, Video & video)
@@ -725,7 +734,7 @@ void Engine::Object::createManagedObject()
             m_ode_object->addSphere(m_args);
             break;
         case OdeWorld::PLANE:
-            while (m_args->size() < 6)
+            while (m_args->size() < 4 || m_args->size() == 5)
                 m_args->push_back(0);
             m_ode_object->addPlane(m_args);
             break;
@@ -745,29 +754,9 @@ void Engine::Object::createManagedObject()
 }
 
 /* render a managed object */
+/* prerequisite: m_args->size() is big enough */
 void Engine::Object::render()
 {
-    bool valid = false;
-    switch (m_geom_type)
-    {
-        case OdeWorld::BOX:
-            if (m_args->size() >= 3)    valid = true;
-            break;
-        case OdeWorld::SPHERE:
-            if (m_args->size() >= 1)    valid = true;
-            break;
-        case OdeWorld::PLANE:
-            if (m_args->size() >= 6)    valid = true;
-            break;
-        case OdeWorld::CYLINDER:
-            if (m_args->size() >= 2)    valid = true;
-            break;
-        case OdeWorld::CCYLINDER:
-            if (m_args->size() >= 2)    valid = true;
-            break;
-    }
-    if (!valid)
-        return;
     if (m_display_list <= 0)
         m_display_list = glGenLists(1);
     glNewList(m_display_list, GL_COMPILE);
@@ -813,30 +802,70 @@ void Engine::Object::render()
             gluSphere(quad, (*m_args)[0], 16, 8);
             break;
         case OdeWorld::PLANE: {
-            dMatrix3 r;
-            dRFromEulerAngles(r, (*m_args)[3], (*m_args)[4], (*m_args)[5]);
-            dVector3 default_plane_direction = {0, 0, 1, 0};
-            dVector3 default_x = {1, 0, 0, 0};
-            dVector3 default_y = {0, 1, 0, 0};
-            dVector3 rotated_plane_direction;
+            dVector3 normal;
             dVector3 rotated_x;
             dVector3 rotated_y;
-            dMultiply0(rotated_plane_direction, default_plane_direction,
-                    r, 1, 3, 3);
-            dMultiply0(rotated_x, default_x, r, 1, 3, 3);
-            dMultiply0(rotated_y, default_y, r, 1, 3, 3);
+            float x_o, y_o, z_o;
+            if (m_args->size() == 6)
+            {
+                dMatrix3 r;
+                dRFromEulerAngles(r, (*m_args)[3], (*m_args)[4], (*m_args)[5]);
+                dVector3 default_plane_direction = {0, 0, 1, 0};
+                dVector3 default_x = {1, 0, 0, 0};
+                dVector3 default_y = {0, 1, 0, 0};
+                dMultiply0(normal, default_plane_direction,
+                        r, 1, 3, 3);
+                dMultiply0(rotated_x, default_x, r, 1, 3, 3);
+                dMultiply0(rotated_y, default_y, r, 1, 3, 3);
+                x_o = (*m_args)[0];
+                y_o = (*m_args)[1];
+                z_o = (*m_args)[2];
+            }
+            else
+            {
+                normal[0] = (*m_args)[0];
+                normal[1] = (*m_args)[1];
+                normal[2] = (*m_args)[2];
+                float d = (*m_args)[3];
+                float len = normal[0] * normal[0]
+                            + normal[1] * normal[1]
+                            + normal[2] * normal[2];
+                if (! FP_EQ(len, 1.0))          /* normalize if necessary */
+                {
+                    len = sqrtf(len);
+                    normal[0] /= len;
+                    normal[1] /= len;
+                    normal[2] /= len;
+                    d /= len;
+                }
+                int min_component = 0;
+                float comp = 10000.0f;
+                for (int i = 0; i < 3; i++)
+                {
+                    if (normal[i] < comp)
+                    {
+                        min_component = i;
+                        comp = normal[i];
+                    }
+                }
+                dVector3 cross_vec;
+                for (int i = 0; i < 3; i++)
+                    cross_vec[i] = (i == min_component) ? 1 : 0;
+                cross_product(rotated_x, normal, cross_vec);
+                cross_product(rotated_y, normal, rotated_x);
+                x_o = normal[0] * d;
+                y_o = normal[1] * d;
+                z_o = normal[2] * d;
+            }
 
             /* plane equation: ax + by + cz = d, plane normal: (a, b, c) */
 
             const int num_sections = 10;
             const float section_size = 100.0f;
-            float x_o = (*m_args)[0];
-            float y_o = (*m_args)[1];
-            float z_o = (*m_args)[2];
 #ifdef dSINGLE
-            glNormal3fv(rotated_plane_direction);
+            glNormal3fv(normal);
 #else
-            glNormal3dv(rotated_plane_direction);
+            glNormal3dv(normal);
 #endif
             for (int x = 0; x < num_sections; x++)
             {

ag.cc

@@ -378,21 +378,27 @@ namespace ag
     static int createPlaneSpecify(lua_State * L, bool is_static)
     {
         int argc = lua_gettop(L);
-        if (argc == 6 &&
-                lua_isnumber(L, 1) &&
-                lua_isnumber(L, 2) &&
-                lua_isnumber(L, 3) &&
-                lua_isnumber(L, 4) &&
-                lua_isnumber(L, 5) &&
-                lua_isnumber(L, 6))
+        if (argc == 4 || argc == 6)
         {
-            refptr< vector<float> > args = new vector<float>();
-            for (int i = 1; i <= 6; i++)
-                args->push_back(lua_tonumber(L, i));
-            addManagedObject(L, is_static, OdeWorld::PLANE, args);
+            bool valid = true;
+            for (int i = 0; i < argc; i++)
+            {
+                if (!lua_isnumber(L, i))
+                {
+                    valid = false;
+                    break;
+                }
+            }
+            if (valid)
+            {
+                refptr< vector<float> > args = new vector<float>();
+                for (int i = 1; i <= 6; i++)
+                    args->push_back(lua_tonumber(L, i));
+                addManagedObject(L, is_static, OdeWorld::PLANE, args);
+                return 1;
+            }
         }
-        else
-            lua_pushnil(L);
+        lua_pushnil(L);
         return 1;
     }