triangle midpoints

This commit is contained in:
jb 2025-07-08 22:40:11 -07:00
parent 9bb767b58f
commit 434eddee27
3 changed files with 73 additions and 2 deletions

View File

@ -153,6 +153,9 @@ void update(void) {
projected_triangle.points[j] = projected_point;
}
//vec2_t midpoint = triangle_midpoint(projected_triangle);
//draw_rect(midpoint.x, midpoint.y, 10, 10, 0xFFFF0000);
// save the projected triangle in the array of triangles
array_push(triangles_to_render, projected_triangle);
@ -178,13 +181,21 @@ void render(void) {
draw_grid();
// Loop all projected points and render them
for (int i = 0; i < array_length(triangles_to_render); i++) {
/*for (int i = 0; i < array_length(triangles_to_render); i++) {
triangle_t triangle = triangles_to_render[i];
draw_triangle(triangle, 0xFF00FF00);
draw_rect(triangle.points[0].x, triangle.points[0].y, 3, 3, 0xFFFFFF00);
draw_rect(triangle.points[1].x, triangle.points[1].y, 3, 3, 0xFFFFFF00);
draw_rect(triangle.points[2].x, triangle.points[2].y, 3, 3, 0xFFFFFF00);
}
}*/
triangle_t t;
t.points[0] = (vec2_t){ .x = 300, .y = 100 };
t.points[1] = (vec2_t){ .x = 50, .y = 400 };
t.points[2] = (vec2_t){ .x = 500, .y = 700 };
//draw_triangle(t, 0xFF00FF00);
vec2_t m = triangle_midpoint(t);
//draw_rect(m.x, m.y, 10, 10, 0xFFFF0000);
//draw_line(10, 10, 500, 500, 0x00FF00);
array_free(triangles_to_render);

View File

@ -1,3 +1,61 @@
#include "triangle.h"
#include "display.h"
// TODO: Create implementation for triangle.h functions
int compare_vec2_t(const void* a, const void* b) {
const vec2_t* arg1 = (const vec2_t*)a;
const vec2_t* arg2 = (const vec2_t*)b;
if (arg1->y < arg2->y) return -1;
if (arg1->y > arg2->y) return 1;
return 0;
}
void fill_flat_bottom_triangle(triangle_t triangle) {
}
void fill_flat_top_triangle(triangle_t triangle) {
}
vec2_t triangle_midpoint(triangle_t triangle) {
// sort by y
int temp = 0, min_idx = 0, mid_idx = 1, max_idx = 2;
if (triangle.points[min_idx].y > triangle.points[mid_idx].y) {
temp = min_idx; min_idx = mid_idx; mid_idx = temp;
}
if (triangle.points[min_idx].y > triangle.points[max_idx].y) {
temp = min_idx; min_idx = max_idx; max_idx = temp;
}
if (triangle.points[mid_idx].y > triangle.points[max_idx].y) {
temp = mid_idx; mid_idx = max_idx; max_idx = temp;
}
// check for division by zero
if (triangle.points[max_idx].y == triangle.points[min_idx].y) {
// Degenerate case, return something reasonable
return triangle.points[mid_idx]; // or some fallback
}
vec2_t midpoint;
midpoint.y = triangle.points[mid_idx].y;
midpoint.x = (((triangle.points[max_idx].x - triangle.points[min_idx].x) * (triangle.points[mid_idx].y - triangle.points[min_idx].y)) / (triangle.points[max_idx].y - triangle.points[min_idx].y)) + triangle.points[min_idx].x;
triangle_t flat_top, flat_bottom;
flat_bottom.points[0] = triangle.points[min_idx];
flat_bottom.points[1] = triangle.points[mid_idx];
flat_bottom.points[2] = midpoint;
flat_top.points[0] = triangle.points[mid_idx];
flat_top.points[1] = triangle.points[max_idx];
flat_top.points[2] = midpoint;
draw_triangle(flat_bottom, 0xFF00FF00);
draw_triangle(flat_top, 0xF0000FF);
return midpoint;
}

View File

@ -13,4 +13,6 @@ typedef struct {
vec2_t points[3];
} triangle_t;
vec2_t triangle_midpoint(triangle_t triangle);
#endif