abdelrahman/cg-from-scratch
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Apply transformation first then project the points

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Abdelrahman Said 2024-07-07 23:19:29 +01:00
parent 9d929c22ba
commit 26fc513d4a
2 changed files with 20 additions and 8 deletions
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1
include/rasteriser/rasteriser.h
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@ -18,6 +18,7 @@ typedef struct {
MAKE_LIST_TYPE(f32); MAKE_LIST_TYPE(f32);
MAKE_LIST_TYPE(vec2i_t); MAKE_LIST_TYPE(vec2i_t);
MAKE_LIST_TYPE(vec3f_t); MAKE_LIST_TYPE(vec3f_t);
MAKE_LIST_TYPE(vec4f_t);
MAKE_LIST_TYPE(scene_triangle_t); MAKE_LIST_TYPE(scene_triangle_t);
typedef struct { typedef struct {

27
src/rasteriser/rasteriser.c
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@ -31,9 +31,9 @@ void render_scene(window_t *wnd, Arena *arena,
void render_instance(window_t *wnd, Arena *arena, mat4x4f_t camera_matrix, void render_instance(window_t *wnd, Arena *arena, mat4x4f_t camera_matrix,
mat3x4f_t projection_matrix, const instance_t *instance) { mat3x4f_t projection_matrix, const instance_t *instance) {
list_vec2i_t *projected = list_create_with_capacity( list_vec4f_t *transformed = list_create_with_capacity(
vec2i_t, arena, instance->model->vertices->count * sizeof(vec3f_t)); vec4f_t, arena, instance->model->vertices->count * sizeof(vec4f_t));
if (!projected) { if (!transformed) {
return; return;
} }
@ -47,14 +47,25 @@ void render_instance(window_t *wnd, Arena *arena, mat4x4f_t camera_matrix,
mat4x4f_t xf_cam_mat = mul_mat4x4f(camera_matrix, trs_mat); mat4x4f_t xf_cam_mat = mul_mat4x4f(camera_matrix, trs_mat);
mat3x4f_t xf_proj_mat = mul_mat3x4f_by_mat4x4f(projection_matrix, xf_cam_mat);
vec3f_t vertex = {0}; vec3f_t vertex = {0};
vec2i_t point = {0}; vec4f_t xf_vertex = {0};
for (u64 i = 0; i < instance->model->vertices->count; ++i) { for (u64 i = 0; i < instance->model->vertices->count; ++i) {
vertex = list_get(instance->model->vertices, i); vertex = list_get(instance->model->vertices, i);
vertex = mul_mat3x4f_by_vec4f( xf_vertex = mul_mat4x4f_by_vec4f(
xf_proj_mat, (vec4f_t){vertex.x, vertex.y, vertex.z, 1.0f}); xf_cam_mat, (vec4f_t){vertex.x, vertex.y, vertex.z, 1.0f});
list_append(vec4f_t, arena, transformed, xf_vertex);
}
list_vec2i_t *projected = list_create_with_capacity(
vec2i_t, arena, instance->model->vertices->count * sizeof(vec2i_t));
if (!projected) {
return;
}
vec2i_t point = {0};
for (u64 i = 0; i < transformed->count; ++i) {
xf_vertex = list_get(transformed, i);
vertex = mul_mat3x4f_by_vec4f(projection_matrix, xf_vertex);
point = (vec2i_t){(i32)(vertex.x / vertex.z), (i32)(vertex.y / vertex.z)}; point = (vec2i_t){(i32)(vertex.x / vertex.z), (i32)(vertex.y / vertex.z)};
list_append(vec2i_t, arena, projected, point); list_append(vec2i_t, arena, projected, point);
} }