From 2f126f95ff7d4e30010d79faddcd69081897e3a8 Mon Sep 17 00:00:00 2001
From: Abdelrahman <said.abdelrahman89@gmail.com>
Date: Mon, 12 Aug 2024 00:24:12 +0100
Subject: [PATCH] Implement camera movement
---
src/obj.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 95 insertions(+), 8 deletions(-)
diff --git a/src/obj.c b/src/obj.c
index 4b8a2a6..e5b562c 100644
--- a/src/obj.c
+++ b/src/obj.c
@@ -28,13 +28,55 @@
V.x /= magnitude; \
V.y /= magnitude; \
V.z /= magnitude; \
- } while (0);
+ } while (0)
#define cross_product(V1, V2) \
((V3f){ \
.x = V1.y * V2.z - V1.z * V2.y, \
.y = V1.z * V2.x - V1.x * V2.z, \
.z = V1.x * V2.y - V1.y * V2.x, \
})
+#define mat4x4_identity \
+ ((M4x4f){ \
+ .row0 = {1.0f, 0.0f, 0.0f, 0.0f}, \
+ .row1 = {0.0f, 1.0f, 0.0f, 0.0f}, \
+ .row2 = {0.0f, 0.0f, 1.0f, 0.0f}, \
+ .row3 = {0.0f, 0.0f, 0.0f, 1.0f}, \
+ })
+#define mat4x4_mul(MAT1, MAT2) \
+ ((M4x4f){ \
+ .row0.x = MAT1.row0.x * MAT2.row0.x + MAT1.row0.y * MAT2.row1.x + \
+ MAT1.row0.z * MAT2.row2.x + MAT1.row0.w * MAT2.row3.x, \
+ .row0.y = MAT1.row0.x * MAT2.row0.y + MAT1.row0.y * MAT2.row1.y + \
+ MAT1.row0.z * MAT2.row2.y + MAT1.row0.w * MAT2.row3.y, \
+ .row0.z = MAT1.row0.x * MAT2.row0.z + MAT1.row0.y * MAT2.row1.z + \
+ MAT1.row0.z * MAT2.row2.z + MAT1.row0.w * MAT2.row3.z, \
+ .row0.w = MAT1.row0.x * MAT2.row0.w + MAT1.row0.y * MAT2.row1.w + \
+ MAT1.row0.z * MAT2.row2.w + MAT1.row0.w * MAT2.row3.w, \
+ .row1.x = MAT1.row1.x * MAT2.row0.x + MAT1.row1.y * MAT2.row1.x + \
+ MAT1.row1.z * MAT2.row2.x + MAT1.row1.w * MAT2.row3.x, \
+ .row1.y = MAT1.row1.x * MAT2.row0.y + MAT1.row1.y * MAT2.row1.y + \
+ MAT1.row1.z * MAT2.row2.y + MAT1.row1.w * MAT2.row3.y, \
+ .row1.z = MAT1.row1.x * MAT2.row0.z + MAT1.row1.y * MAT2.row1.z + \
+ MAT1.row1.z * MAT2.row2.z + MAT1.row1.w * MAT2.row3.z, \
+ .row1.w = MAT1.row1.x * MAT2.row0.w + MAT1.row1.y * MAT2.row1.w + \
+ MAT1.row1.z * MAT2.row2.w + MAT1.row1.w * MAT2.row3.w, \
+ .row2.x = MAT1.row2.x * MAT2.row0.x + MAT1.row2.y * MAT2.row1.x + \
+ MAT1.row2.z * MAT2.row2.x + MAT1.row2.w * MAT2.row3.x, \
+ .row2.y = MAT1.row2.x * MAT2.row0.y + MAT1.row2.y * MAT2.row1.y + \
+ MAT1.row2.z * MAT2.row2.y + MAT1.row2.w * MAT2.row3.y, \
+ .row2.z = MAT1.row2.x * MAT2.row0.z + MAT1.row2.y * MAT2.row1.z + \
+ MAT1.row2.z * MAT2.row2.z + MAT1.row2.w * MAT2.row3.z, \
+ .row2.w = MAT1.row2.x * MAT2.row0.w + MAT1.row2.y * MAT2.row1.w + \
+ MAT1.row2.z * MAT2.row2.w + MAT1.row2.w * MAT2.row3.w, \
+ .row3.x = MAT1.row3.x * MAT2.row0.x + MAT1.row3.y * MAT2.row1.x + \
+ MAT1.row3.z * MAT2.row2.x + MAT1.row3.w * MAT2.row3.x, \
+ .row3.y = MAT1.row3.x * MAT2.row0.y + MAT1.row3.y * MAT2.row1.y + \
+ MAT1.row3.z * MAT2.row2.y + MAT1.row3.w * MAT2.row3.y, \
+ .row3.z = MAT1.row3.x * MAT2.row0.z + MAT1.row3.y * MAT2.row1.z + \
+ MAT1.row3.z * MAT2.row2.z + MAT1.row3.w * MAT2.row3.z, \
+ .row3.w = MAT1.row3.x * MAT2.row0.w + MAT1.row3.y * MAT2.row1.w + \
+ MAT1.row3.z * MAT2.row2.w + MAT1.row3.w * MAT2.row3.w, \
+ })
#define mat4x4_mul_vec4(MAT, V) \
((V4f){ \
.x = MAT.row0.x * V.x + MAT.row0.y * V.y + MAT.row0.z * V.z + \
@@ -58,13 +100,12 @@ struct triangle_bbox {
internal void render_triangle(const Triangle *triangle, const Model *model,
Render *render, Colour colour, RenderType type,
- ProjectionType projection);
+ ProjectionType projection, M4x4f mv);
internal void fill_triangle(Render *render, V3f vertices[TRIANGLE_VERTICES],
V3f normals[TRIANGLE_VERTICES],
V2f coordinates[TRIANGLE_VERTICES], Colour colour,
Image *texture, RenderType type);
-internal void reorder_points(V2u vertices[TRIANGLE_VERTICES],
- V2f coordinates[TRIANGLE_VERTICES]);
+internal M4x4f lookat(V3f eye, V3f target, V3f up);
internal TriangleBBox get_triangle_bbox(const Image *img,
V3f vertices[TRIANGLE_VERTICES]);
internal V3f get_barycentric_coords(f32 d00, f32 d01, f32 d11, f32 denom,
@@ -85,6 +126,10 @@ M4x4f g_cam_matrix = {
};
// clang-format on
+V3f g_eye = {0.2f, 0.1f, 0.7f};
+V3f g_target = {0};
+V3f g_up = {0.0f, 1.0f, 0.0f};
+
Model load_obj_file(Arena *arena, const char *filename, const char *texture) {
if (!arena) {
return INVALID_MODEL;
@@ -182,6 +227,7 @@ void render_model(const Model *model, Render *render, Colour colour,
RenderType type, ColourType colour_type,
ProjectionType projection) {
Triangle triangle;
+ M4x4f model_view = lookat(g_eye, g_target, g_up);
for (u64 i = 0; i < model->triangles->count; ++i) {
triangle = list_get(model->triangles, i);
@@ -191,13 +237,14 @@ void render_model(const Model *model, Render *render, Colour colour,
.b = rand() % UINT8_MAX,
.a = 255};
}
- render_triangle(&triangle, model, render, colour, type, projection);
+ render_triangle(&triangle, model, render, colour, type, projection,
+ model_view);
}
}
internal void render_triangle(const Triangle *triangle, const Model *model,
Render *render, Colour colour, RenderType type,
- ProjectionType projection) {
+ ProjectionType projection, M4x4f mv) {
Image *img = &(render->img);
V3f vertices[TRIANGLE_VERTICES] = {
list_get(model->vertices, triangle->p0),
@@ -215,8 +262,21 @@ internal void render_triangle(const Triangle *triangle, const Model *model,
list_get(model->texture_coordinates, triangle->tx2),
};
+ // Camera
+ for (u64 i = 0; i < TRIANGLE_VERTICES; ++i) {
+ V4f vertex;
+ vertex = (V4f){
+ .x = vertices[i].x,
+ .y = vertices[i].y,
+ .z = vertices[i].z,
+ .w = 1.0f,
+ };
+ vertex = mat4x4_mul_vec4(mv, vertex);
+ vertices[i] = project_vec4(vertex);
+ }
+
+ // Basic perspective projection
if (projection == PROJECTION_TYPE_PERSPECTIVE) {
- // Basic perspective projection
V4f vertex;
for (u64 i = 0; i < TRIANGLE_VERTICES; ++i) {
vertex = (V4f){
@@ -304,7 +364,7 @@ internal void fill_triangle(Render *render, V3f vertices[TRIANGLE_VERTICES],
}
if (intensity < 0.0f) {
- continue;
+ intensity = 0.01f;
}
if (texture) {
@@ -329,6 +389,33 @@ internal void fill_triangle(Render *render, V3f vertices[TRIANGLE_VERTICES],
}
}
+internal M4x4f lookat(V3f eye, V3f target, V3f up) {
+ V3f z = V3(V3f, f32, target.x, target.y, target.z, eye.x, eye.y, eye.z);
+ normalise_v3(z);
+ V3f x = cross_product(up, z);
+ normalise_v3(x);
+ V3f y = cross_product(z, x);
+ normalise_v3(y);
+
+ M4x4f rotation = mat4x4_identity;
+ rotation.row0.x = x.x;
+ rotation.row0.y = x.y;
+ rotation.row0.z = x.z;
+ rotation.row1.x = y.x;
+ rotation.row1.y = y.y;
+ rotation.row1.z = y.z;
+ rotation.row2.x = z.x;
+ rotation.row2.y = z.y;
+ rotation.row2.z = z.z;
+
+ M4x4f translation = mat4x4_identity;
+ translation.row0.w = -(eye.x);
+ translation.row1.w = -(eye.y);
+ translation.row2.w = -(eye.z);
+
+ return mat4x4_mul(rotation, translation);
+}
+
internal TriangleBBox get_triangle_bbox(const Image *img,
V3f vertices[TRIANGLE_VERTICES]) {
f32 x0 = min(vertices[0].x, min(vertices[1].x, vertices[2].x));