various improvements

- cleaned up the computation of the camera's matrix
- changed VertexData to being a struct which transmit data between the "vertex shader" and the "fragment shader"
- started working on keyboard and mouse controls
- added fov (field of view)
- changed quaternion to euler angles conversion, from zyx to zxy
- fixed computations of z coordinates in triangle rendering
- improved naming in the triangle rasterizer

2 files changed, 25 insertions, 11 deletions

diff --git a/src/fb/chfb.cpp b/src/fb/chfb.cpp
index 71259aa..8068d8f 100644
--- a/src/fb/chfb.cpp
+++ b/src/fb/chfb.cpp
@@ -4,9 +4,13 @@
 #include "math/vector.h"
 #include "math/quat.h"
 #include "o3d/vertex_data.h"
+#include "o3d/camera.h"
 
 using namespace engine::fb;
-using engine::math::Vector3, engine::math::Quaternion, engine::o3d::VertexData;
+using
+    engine::math::Vector3,
+    engine::o3d::VertexData,
+    engine::o3d::Camera;
 
 CharacterFrameBuffer::CharacterFrameBuffer(unsigned int w, unsigned int h) {
     resize(w, h);
@@ -25,12 +29,12 @@ void CharacterFrameBuffer::clear() {
 
 // taken from https://stackoverflow.com/a/74186686
 char brightness_chars[] = " `.-':_,^=;><+!rc*/z?sLTv)J7(|Fi{C}fI31tlu[neoZ5Yxjya]2ESwqkP6h9d4VpOGbUAKXHm8RD#$Bg0MNWQ%&@";
-extern Quaternion camera_quat;
+extern Camera* camera;
 
 void CharacterFrameBuffer::draw_point(int x, int y, const Vector3& loc, const VertexData& vd, const Vector3& normal) {
     (void) loc;
     (void) vd;
-    auto v = normal.rot(camera_quat.conjugate());
+    auto v = normal.rot(camera->transform.rot.conjugate());
     float light = .1f + (v.z < 0.f ? 0.f : v.z) * .9f;
     std::uint32_t c = (int) (light * static_cast<float>(sizeof(brightness_chars) - 1));
     chars_vector[x + y * w] = brightness_chars[c];
diff --git a/src/fb/pixfb.cpp b/src/fb/pixfb.cpp
index a8d6bee..d49566e 100644
--- a/src/fb/pixfb.cpp
+++ b/src/fb/pixfb.cpp
@@ -4,9 +4,13 @@
 #include "math/vector.h"
 #include "math/quat.h"
 #include "o3d/vertex_data.h"
+#include "o3d/camera.h"
 
 using namespace engine::fb;
-using engine::math::Vector3, engine::o3d::VertexData;
+using
+    engine::math::Vector3,
+    engine::o3d::VertexData,
+    engine::o3d::Camera;
 
 PixelFrameBuffer::PixelFrameBuffer(unsigned int w, unsigned int h) {
     resize(w, h);
@@ -23,16 +27,22 @@ void PixelFrameBuffer::clear() {
     std::fill(pixels_vector.begin(), pixels_vector.end(), 0x000000FF);
 }
 
-extern engine::math::Quaternion camera_quat;
+extern Camera* camera;
 
 void PixelFrameBuffer::draw_point(int x, int y, const Vector3& loc, const VertexData& vd, const Vector3& normal) {
     (void) loc;
     (void) vd;
-    // int ir = ((int) (((float) ((int) (vd.tx * 10.f))) * 25.5f));
-    // int ig = ((int) (((float) ((int) (vd.ty * 10.f))) * 25.5f));
-    // pixels_vector[x + y * w] = (ir << 24) | (ig << 16) | 0xFFFF;
-    auto v = normal.rot(camera_quat.conjugate());
-    float light = .1f + (v.z < 0.f ? 0.f : v.z) * .9f;
-    std::uint32_t c = (int) (light * 255.f);
+    auto u = vd.world_loc - camera->transform.loc;
+    float u_len_sq = u.length_squared();
+    u = u.normalize();
+    float attenuation = Vector3(0.f, 0.f, -1.f).rot(camera->transform.rot).dot(u);
+    if (attenuation < .7f) attenuation = 0.f;
+    else if (attenuation > .8f) attenuation = 1.f;
+    else attenuation = (attenuation - .7f) / .1f;
+    float light = -normal.dot(u) / u_len_sq;
+    if (light < 0.f) light = 0.f;
+    float final_light = .05f + light * attenuation * .8f * .95f;
+    if (final_light > 1.f) final_light = 1.f;
+    std::uint32_t c = (int) (final_light * 255.f);
     pixels_vector[x + y * w] = c << 24 | c << 16 | c << 8 | 0xff;
 }