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Fix my sphere #15

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Merged
btipling merged 16 commits into from
Aug 21, 2024
Merged

Fix my sphere #15

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b07151c
build end
btipling Aug 20, 2024
6991e34
moare prog
btipling Aug 20, 2024
9d03bc2
the ends work
btipling Aug 20, 2024
569d923
use arg
btipling Aug 20, 2024
53dfde9
1 triangle
btipling Aug 20, 2024
af1505c
Yep
btipling Aug 20, 2024
b1ca0a7
this works so far
btipling Aug 20, 2024
3565348
2 quads in grid done
btipling Aug 20, 2024
e1dcb19
got an entire grid row working
btipling Aug 20, 2024
6a79650
completed row correct
btipling Aug 20, 2024
78abf60
works with culling
btipling Aug 20, 2024
9354eb4
remove extra var
btipling Aug 20, 2024
bcdcad2
avoid hard coded value
btipling Aug 20, 2024
dff568d
moar sphere
btipling Aug 20, 2024
038a508
beautiful sphere
btipling Aug 20, 2024
f6c7f3c
remove default setting
btipling Aug 20, 2024
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151 changes: 111 additions & 40 deletions src/foundations/object/object_sphere/ObjectSphere.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -4,11 +4,16 @@ instance_data_stride: usize,

const Sphere = @This();
const angle_delta: f32 = std.math.pi * 0.02;
const x_angle_delta = angle_delta / 2.0;
const x_grid_rows: f32 = std.math.pi * 2.0 - angle_delta * 1.5;
const grid_dimension: usize = @intFromFloat((2.0 * std.math.pi) / angle_delta);
const num_vertices: usize = grid_dimension * grid_dimension;
const quad_dimensions = grid_dimension - 1;
const num_quads = quad_dimensions * quad_dimensions;
const num_indices: usize = num_quads * 6;
const num_triangles = quad_dimensions;
const num_triangles_in_end = quad_dimensions * 2;
const num_quads_in_grid = ((x_grid_rows - x_angle_delta * 2) / x_angle_delta) * grid_dimension;
const num_vertices: usize = (num_triangles_in_end * 2 + 1) + (3 * grid_dimension) * (3 * grid_dimension) + (num_triangles_in_end * 2 + 1);
const num_indices: usize = (grid_dimension * 3) + 6 * num_quads_in_grid + (grid_dimension * 3);
const sphere_scale: f32 = 0.75;

pub fn init(
Expand All @@ -26,9 +31,6 @@ pub fn init(
.vao = vao_buf.vao,
.buffer = vao_buf.buffer,
.wire_mesh = wireframe,
// TODO: this code has a degenerate triangle, cull face bug at when i % grid_dimension == 0
// I have to do the math on paper to figure this out.
.cull = false,
.instance_type = .{
.instanced = .{
.index_count = num_indices,
Expand All @@ -51,51 +53,120 @@ pub fn updateInstanceAt(self: Sphere, index: usize, instance_data: rhi.instanceD
fn data() struct { attribute_data: [num_vertices]rhi.attributeData, indices: [num_indices]u32 } {
var attribute_data: [num_vertices]rhi.attributeData = undefined;
var indices: [num_indices]u32 = undefined;
var x_axis_angle: f32 = 0;

const x_angle_delta: f32 = angle_delta;
const y_angle_delta = angle_delta;
var x_axis_angle: f32 = x_angle_delta;
var y_axis_angle: f32 = y_angle_delta;

var positions: [num_vertices]math.vector.vec3 = undefined;
{
var pi: usize = 0;
while (x_axis_angle < 2 * std.math.pi) : (x_axis_angle += x_angle_delta) {
const y_angle_delta: f32 = x_angle_delta;
var y_axis_angle: f32 = 0;
while (y_axis_angle < 2 * std.math.pi) : (y_axis_angle += y_angle_delta) {
positions[pi] = math.rotation.sphericalCoordinatesToCartesian3D(math.vector.vec3, .{
1.0,
y_axis_angle,
x_axis_angle,
});
pi += 1;
}
}
const r: f32 = 1.0;

const start: math.vector.vec3 = .{ 1, 0, 0 };
const end: math.vector.vec3 = .{ -1, 0, 0 };
positions[0] = start;
positions[1] = end;
var pi: usize = 2;
while (y_axis_angle <= std.math.pi * 2 + y_angle_delta) : (y_axis_angle += y_angle_delta) {
positions[pi] = .{
r * @cos(x_axis_angle),
r * @sin(x_axis_angle) * @sin(y_axis_angle),
r * @sin(x_axis_angle) * @cos(y_axis_angle),
};
pi += 1;
}
y_axis_angle += y_angle_delta;
x_axis_angle += x_angle_delta;

var ii: usize = 0;
var i: u32 = 0;
var pii: u32 = 1;
while (i < num_triangles) : (i += 1) {
indices[ii] = 0;
indices[ii + 1] = pii + 1;
indices[ii + 2] = pii + 2;
ii += 3;
pii += 1;
}
indices[ii] = 0;
indices[ii + 1] = pii + 1;
indices[ii + 2] = 2;
ii += 3;
pii += 2;

var iii: usize = 2;
while (x_axis_angle < x_grid_rows) : (x_axis_angle += x_angle_delta) {
const start_iii = iii;
y_axis_angle = y_angle_delta;
for (0..grid_dimension) |ri| {
positions[pi] = .{
r * @cos(x_axis_angle),
r * @sin(x_axis_angle) * @sin(y_axis_angle),
r * @sin(x_axis_angle) * @cos(y_axis_angle),
};
pi += 1;
y_axis_angle += y_angle_delta;
positions[pi] = .{
r * @cos(x_axis_angle),
r * @sin(x_axis_angle) * @sin(y_axis_angle),
r * @sin(x_axis_angle) * @cos(y_axis_angle),
};
pi += 1;
{
var tr = iii + 1;
if (ri == grid_dimension - 1) {
tr = start_iii;
}
const br = iii + grid_dimension + 1;
const tl = iii;
const bl = iii + grid_dimension;

{
var ii: usize = 0;
var last: usize = 0;
var fl: usize = 0;
var sl: usize = 0;
for (0..quad_dimensions) |_| {
for (0..quad_dimensions) |_| {
const i = fl + sl;
const tr = i + 1;
const br = i + grid_dimension + 1;
const tl = i;
var bl = i + grid_dimension;
bl += 0;

addVertexData(positions, indices[0..], attribute_data[0..], tr, br, tl, bl, ii);
// Triangle 1
indices[ii] = @intCast(tl);
indices[ii + 1] = @intCast(bl);
indices[ii + 2] = @intCast(br);

// Triangle 2
indices[ii + 3] = @intCast(tl);
indices[ii + 4] = @intCast(br);
indices[ii + 5] = @intCast(tr);

ii += 6;
last = br;
fl += 1;
iii += 1;
}
sl += 1;
y_axis_angle += y_angle_delta;
pii += 2;
}
}

y_axis_angle = y_angle_delta;
x_axis_angle = std.math.pi + x_angle_delta;
while (y_axis_angle <= std.math.pi * 2 + y_angle_delta) : (y_axis_angle += y_angle_delta) {
positions[pi] = .{
r * @cos(x_axis_angle),
r * @sin(x_axis_angle) * @sin(y_axis_angle),
r * @sin(x_axis_angle) * @cos(y_axis_angle),
};
pi += 1;
}

i = 0;
const closer = pii;
while (i < num_triangles) : (i += 1) {
indices[ii + 2] = 1;
indices[ii + 1] = pii + 0;
indices[ii] = pii + 1;
ii += 3;
pii += 1;
}
indices[ii + 2] = 1;
indices[ii + 1] = pii;
indices[ii] = closer;
var adi: usize = 0;

while (adi < pi) : (adi += 1) {
attribute_data[adi].position = positions[adi];
attribute_data[adi].normals = math.vector.normalize(positions[adi]);
}

return .{ .attribute_data = attribute_data, .indices = indices };
}

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