cube foo init

inc/mesh.hpp

@@ -14,9 +14,9 @@ typedef struct TRIANGLE {
 } TRIANGLE;
 
 class Mesh {
-protected:
-  usu::vector<VECTOR> m_vertices;
-  usu::vector<TRIANGLE> m_triangles;
+public:
+  usu::vector<VECTOR> vertices;
+  usu::vector<TRIANGLE> triangles;
 };
 
 #endif // MESH_HPP

inc/model_instance.hpp

@@ -8,10 +8,14 @@
 class ModelInstance : Renderable {
 private:
   FIXED m_scale;
-  VECTOR m_rotation;
+  VECTOR m_rotation; // though technically "FIXED"'s, these are simply s32's
+                     // where [0, 2pi] -> [0, 0xFFFF] in the x,y,z axes
   VECTOR m_pos;
 
   std::shared_ptr<Mesh> m_mesh;
+
+public:
+  void render(std::shared_ptr<Scene> scene_context);
 };
 
 #endif // MODEL_INSTANCE_HPP

inc/scene.hpp

@@ -1,20 +1,23 @@
-#ifndef CANVAS_HPP
-#define CANVAS_HPP
+#ifndef SCENE_HPP
+#define SCENE_HPP
 
-#include "mesh.hpp"
+#include "model_instance.hpp"
 #include "vector.hpp"
 #include <cstdint>
+#include <tonc.h>
 
 class Scene {
-private:
-  usu::vector<Mesh> meshes;
-  std::uint32_t width;
-  std::uint32_t height;
-
 public:
-  Scene();
+  usu::vector<Renderable> renderables;
+  std::tuple<std::uint16_t, std::uint16_t>
+      viewport_dimension; // <width, height>
+  std::tuple<std::uint16_t, std::uint16_t> scene_dimension;
+  VECTOR directional_light;
+  FIXED z_plane;
 
+  Scene();
   void render();
+  POINT project_2d(VECTOR vertex);
 };
 
 #endif // SCENE_HPP

src/cube.cpp

@@ -2,5 +2,5 @@
 
 Cube::Cube() {
   for (std::uint8_t i = 0; i < 8; ++i)
-    m_vertices.add({(i >> 2) & 1, (i >> 1) & 1, i & 1});
+    vertices.add({(i >> 2) & 1, (i >> 1) & 1, i & 1});
 }

src/mesh.hpp

@@ -1,11 +0,0 @@
-#include "mesh.hpp"
-#include "scene.hpp"
-#include <tuple>
-
-void Mesh::render(std::shared_ptr<Scene> scene_context) {
-  for (const TRIANGLE triangle : m_triangles) {
-    VECTOR v0 = m_vertices[std::get<0>(triangle.vertex_indices)];
-    VECTOR v1 = m_vertices[std::get<1>(triangle.vertex_indices)];
-    VECTOR v2 = m_vertices[std::get<2>(triangle.vertex_indices)];
-  }
-}

src/model_instance.cpp

@@ -0,0 +1,161 @@
+#include "model_instance.hpp"
+#include "scene.hpp"
+#include <tuple>
+
+/**
+static inline POINT viewportToScreen (POINT *point) {
+    // Convert a viewport coordinate to screen x, y
+    return createPoint(fixed_multiply(point->x, fixed_divide(WINDOW_WIDTH <<
+FIX_SHIFT, viewport_width << FIX_SHIFT)), fixed_multiply(point->y,
+fixed_divide(WINDOW_HEIGHT << FIX_SHIFT, viewport_height << FIX_SHIFT))
+    );
+}
+
+static inline POINT projectVertex(VERTEX *vertex) {
+    // Project a vertex to a point
+    POINT temp;
+    if (vertex->z != 0) {
+        // Make sure we don't divide by zero
+        temp = createPoint(fixed_multiply(vertex->x, fixed_divide(ZPlane <<
+FIX_SHIFT, vertex->z)), fixed_multiply(vertex->y, fixed_divide(ZPlane <<
+FIX_SHIFT, vertex->z))
+        );
+    }
+    else {
+        temp = createPoint(0, 0);
+    }
+    temp = viewportToScreen(&temp);
+    return temp;
+}
+
+void renderInstance(INSTANCE *instance, SDL_Renderer *renderer) {
+    // Render an instance
+        // Array for projected points
+    POINT projected[instance->model->vertices_length];
+        // Pointers for transformed vertices
+    VERTEX *transformed = malloc(sizeof(VERTEX) *
+instance->model->vertices_length);
+
+    for (int i = 0; i < instance->model->vertices_length; i++) {
+        // Apply translation and rotation
+        *(transformed + i) = *(instance->model->vertices + i);
+        applyXRotation((transformed + i), *instance->xRotation);
+        applyYRotation((transformed + i), *instance->yRotation);
+        applyZRotation((transformed + i), *instance->zRotation);
+                *(transformed + i) = addVertices((transformed + i),
+instance->position);
+        // Project vertices
+        projected[i] = projectVertex(transformed + i);
+    }
+    VERTEX n, copyV;
+        // A directional light source
+    VERTEX playerLight = createVertex(0, 0, -1 << FIX_SHIFT);
+    normalizeVertex(&playerLight);
+    TRIANGLE *addr;
+    FIXED intensity;
+    COLOR clr;
+    for (int i = 0; i < instance->model->triangles_length; i++) {
+        // Render the triangle
+        addr = (instance->model->triangles + i);
+        n = computeNormal(transformed, addr);
+        normalizeVertex(&n);
+                // Intensity of light on the triangle
+        intensity = fixed_multiply(dotProduct(&n, &playerLight) + (1 <<
+FIX_SHIFT), 127 << FIX_SHIFT); copyV = *(transformed + addr->v2);
+        normalizeVertex(&copyV);
+
+                // Grayscale color of the triangle from light intensity
+        clr = createColor(intensity >> FIX_SHIFT, intensity >> FIX_SHIFT,
+intensity >> FIX_SHIFT);
+
+        if (dotProduct(&n, &copyV) < 0) {
+                        // The triangle is viewable by the camera
+            drawFilledTriangle(
+                &(projected[addr->v0]),
+                &(projected[addr->v1]),
+                &(projected[addr->v2]),
+                &clr,
+                renderer
+            );
+
+        }
+    }
+        transformed = NULL;
+    free(transformed);
+
+
+
+
+    static inline void applyXRotation(VERTEX *vertex, FIXED xRotation) {
+    // Apply rotation to vertex on x-axis
+    FIXED sinTheta = float_to_fixed(sin(fixed_to_float(xRotation) * (3.14159 /
+180))); FIXED cosTheta = float_to_fixed(cos(fixed_to_float(xRotation) * (3.14159
+/ 180))); FIXED y = vertex->y; FIXED z = vertex->z; vertex->y =
+fixed_multiply(y, cosTheta) - fixed_multiply(z, sinTheta); vertex->z =
+fixed_multiply(z, cosTheta) + fixed_multiply(y, sinTheta);
+}
+
+static inline void applyYRotation(VERTEX *vertex, FIXED yRotation) {
+    // Apply rotation to vertex on y-axis
+    FIXED sinTheta = float_to_fixed(sin(fixed_to_float(yRotation) * (3.14159 /
+180))); FIXED cosTheta = float_to_fixed(cos(fixed_to_float(yRotation) * (3.14159
+/ 180))); FIXED x = vertex->x; FIXED z = vertex->z; vertex->x =
+fixed_multiply(x, cosTheta) + fixed_multiply(z, sinTheta); vertex->z =
+fixed_multiply(z, cosTheta) - fixed_multiply(x, sinTheta);
+}
+
+static inline void applyZRotation(VERTEX *vertex, FIXED zRotation) {
+    // Apply rotation to vertex on z-axis
+    FIXED sinTheta = float_to_fixed(sin(fixed_to_float(zRotation) * (3.14159 /
+180))); FIXED cosTheta = float_to_fixed(cos(fixed_to_float(zRotation) * (3.14159
+/ 180))); FIXED x = vertex->x; FIXED y = vertex->y; vertex->x =
+fixed_multiply(x, cosTheta) - fixed_multiply(y, sinTheta); vertex->y =
+fixed_multiply(y, cosTheta) + fixed_multiply(x, sinTheta);
+}
+}
+ */
+
+VECTOR rotate(VECTOR v, VECTOR rot) {
+  FIXED sin_theta_x, sin_theta_y, sin_theta_z;
+  FIXED cos_theta_x, cos_theta_y, cos_theta_z;
+  VECTOR res = {v.x, v.y, v.z};
+
+  if (rot.x != 0) {
+    sin_theta_x = lu_sin(rot.x) >> 4;
+    cos_theta_x = lu_cos(rot.x) >> 4;
+    res.y = fxmul(res.y, cos_theta_x) - fxmul(res.z, sin_theta_x);
+    res.z = fxmul(res.z, cos_theta_x) + fxmul(res.y, sin_theta_x);
+  }
+
+  if (rot.y != 0) {
+    sin_theta_y = lu_sin(rot.y) >> 4;
+    cos_theta_y = lu_cos(rot.y) >> 4;
+    res.x = fxmul(res.x, cos_theta_y) + fxmul(res.z, sin_theta_y);
+    res.z = fxmul(res.z, cos_theta_y) - fxmul(res.x, sin_theta_y);
+  }
+
+  if (rot.z != 0) {
+    sin_theta_z = lu_sin(rot.z) >> 4;
+    cos_theta_z = lu_cos(rot.z) >> 4;
+    res.x = fxmul(res.x, cos_theta_z) - fxmul(res.y, sin_theta_z);
+    res.y = fxmul(res.z, cos_theta_z) + fxmul(res.x, sin_theta_z);
+  }
+
+  return res;
+};
+
+void ModelInstance::render(std::shared_ptr<Scene> scene_context) {
+  usu::vector<VECTOR> transformed(m_mesh->vertices.size());
+  usu::vector<POINT> projected(transformed.size());
+
+  for (std::uint32_t i = 0; i < transformed.size(); i++) {
+    transformed[i] = rotate(m_mesh->vertices[i], m_rotation);
+    projected[i] = scene_context->project_2d(m_mesh->vertices[i]);
+  }
+
+  for (const TRIANGLE triangle : m_mesh->triangles) {
+    VECTOR v0 = transformed[std::get<0>(triangle.vertex_indices)];
+    VECTOR v1 = transformed[std::get<1>(triangle.vertex_indices)];
+    VECTOR v2 = transformed[std::get<2>(triangle.vertex_indices)];
+  }
+}

src/scene.cpp

@@ -0,0 +1,29 @@
+#include "scene.hpp"
+#include <memory>
+
+Scene::Scene() {
+  directional_light = {0, 0, -1};
+  viewport_dimension = {2, 3};
+  scene_dimension = {SCREEN_WIDTH, SCREEN_HEIGHT};
+
+  z_plane = int2fx(1);
+}
+
+void Scene::render() {
+  auto this_ptr = std::make_shared<Scene>(this);
+  for (auto renderable : renderables) {
+    renderable.render(this_ptr);
+  }
+}
+
+POINT Scene::project_2d(VECTOR vertex) {
+  POINT pt = {0, 0};
+
+  if (vertex.z != 0) {
+    pt.x = fxdiv(z_plane, vertex.z);
+    pt.y = fxmul(vertex.y, pt.x);
+    pt.x = fxmul(vertex.x, pt.x);
+  }
+
+  return pt;
+}