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rewrite camera to use matrices
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@mixtur
mixtur committed Jul 14, 2024
1 parent e643731 commit c1bb56b
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Showing 16 changed files with 270 additions and 114 deletions.
169 changes: 165 additions & 4 deletions src/codegen/mat.mjs
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Original file line number Diff line number Diff line change
Expand Up @@ -9,8 +9,8 @@ const gen_type_name = ({rows, cols}) => {
: `Mat${rows}x${cols}`;
};

const get_idx_fn = (t) => {
return (row_index, col_index) => col_index * t.rows + row_index;
const get_idx_fn = (matrix_layout) => {
return (row_index, col_index) => col_index * matrix_layout.rows + row_index;
};

// we follow the standard math notation, where m12 is an element on row 1 and column 2
Expand Down Expand Up @@ -586,9 +586,160 @@ export const gen_transpose = (template) => (use_result_arg) => {
return gen_fn(name, signature, body, use_result_arg);
}

export const gen_gl_asymmetric_perspective_projection = (use_result_arg) => {
const name = 'gl_asymmetric_perspective_projection_to_mat4';
const signature = gen_signature(use_result_arg, sig('Mat4', 'left: number, right: number, bottom: number, top: number, near: number, far: number'));
const preamble = [
'const near2 = near * 2;',
'const inv_width = 1 / (right - left);',
'const inv_height = 1 / (top - bottom);',
'let m10, m14;',
'if (Number.isFinite(far)) {',
' const inv_neg_depth = 1 / (near - far);',
' m10 = (near + far) * inv_neg_depth;',
' m14 = near2 * far * inv_neg_depth;',
'} else {',
' m10 = -1;',
' m14 = -near2;',
'}',
].map(x => ind + x).join('\n');

const components = [
'near2 * inv_width',
'0',
'0',
'0',
'0',
'near2 * inv_height',
'0',
'0',
'(left + right) * inv_width',
'(bottom + top) * inv_height',
'm10',
'-1',
'0',
'0',
'm14',
'0',
];
const body = [
preamble,
gen_output(use_result_arg, 'mat4', components)
].join('\n\n');

return gen_fn(name, signature, body, use_result_arg);
};

export const gen_gl_perspective_projection = (use_result_arg) => {
const name = `gl_perspective_projection`;
const signature = gen_signature(use_result_arg, sig('Mat4', 'aspect: number, y_fov: number, near: number, far: number'));
const preamble = [
ind + 'const top = near * Math.tan(y_fov * 0.5);',
ind + 'const right = top * aspect;',
].join('\n');

const body = [
preamble,
use_result_arg
? ind + `gl_asymmetric_perspective_projection_to_mat4_r(result, -right, right, -top, top, near, far);`
: ind + `return gl_asymmetric_perspective_projection_to_mat4(-right, right, -top, top, near, far);`
].join('\n\n');

return gen_fn(name, signature, body, use_result_arg);
}

export const gen_look_direction_to_mat = (matrix_layout) => (use_result_arg) => {
const mat_type_name = gen_type_name(matrix_layout);

const mat_name = mat_type_name.toLowerCase();

const fn_name = `look_direction_to_${mat_name}`;
const signature = gen_signature(use_result_arg, sig(mat_type_name, `direction: Vec3, up: Vec3`));

const preamble = [
'const x = vec3_dirty();',
'const y = vec3_dirty();',
'const z = vec3_dirty();',
'',
'z.set(direction);',
'unit_vec3_r(z, z);',
'',
'if (!z.every(Number.isFinite)) {',
'orthogonal_vec3_r(z, up);',
'unit_vec3_r(z, z);',
'} else {',
'negate_vec3_r(z, z);',
'}',
'',
'cross_vec3_r(x, up, z);',
'unit_vec3_r(x, x);',
'if (!x.every(Number.isFinite)) {',
'orthogonal_vec3_r(x, z);',
'}',
'cross_vec3_r(y, z, x);'
].map(x => ind + x).join('\n');

const components = [
'x[0]',
'x[1]',
'x[2]',
'0',
'y[0]',
'y[1]',
'y[2]',
'0',
'z[0]',
'z[1]',
'z[2]',
'0',
'0',
'0',
'0',
'1',
].filter((x, i) => {
const col_index = Math.floor(i / 4);
const row_index = i % 4;
return matrix_layout.template[row_index][col_index] === s;
});

const body = [
preamble,
gen_output(use_result_arg, mat_name, components)
].join('\n\n');

return gen_fn(fn_name, signature, body, use_result_arg);
}

export const gen_look_target_to_mat = (matrix_layout) => (use_result_arg) => {
const mat_type_name = gen_type_name(matrix_layout);

const mat_name = mat_type_name.toLowerCase();

const fn_name = `look_target_to_${mat_name}`;
const signature = gen_signature(use_result_arg, sig(mat_type_name, `origin: Vec3, target: Vec3, up: Vec3`));
const get_idx = get_idx_fn(matrix_layout);

const body = [
// const direction = new Vector3().fromVector(target).subtractVector(origin);
'const direction = sub_vec3(target, origin);',
use_result_arg
? `look_direction_to_${mat_name}_r(result, direction, up);`
: `const result = look_direction_to_${mat_name}(direction, up);`,
`result[${get_idx(0, 3)}] = origin[0];`,
`result[${get_idx(1, 3)}] = origin[1];`,
`result[${get_idx(2, 3)}] = origin[2];`,
...(use_result_arg
? []
: ['return result;']
)
].map(x => ind + x).join('\n');

return gen_fn(fn_name, signature, body, use_result_arg);
}

export const gen_mat_module = () => {
const module_code = [
`import {Vec3, vec3} from './vec3.gen'`,
`import {Vec3, vec3, vec3_dirty, unit_vec3_r, orthogonal_vec3_r, negate_vec3_r, cross_vec3_r, sub_vec3} from './vec3.gen'`,
`import {Quat} from './quat.gen'`,
`import { run_hook } from '../utils';`,
gen_mat_preamble(lin),
Expand Down Expand Up @@ -633,7 +784,17 @@ export const gen_mat_module = () => {

gen_trs_to_mat(lin),
gen_trs_to_mat(aff),
gen_trs_to_mat(hom)
gen_trs_to_mat(hom),

gen_gl_asymmetric_perspective_projection,
gen_gl_perspective_projection,

gen_look_direction_to_mat(lin),
gen_look_direction_to_mat(aff),
gen_look_direction_to_mat(hom),

gen_look_target_to_mat(aff),
gen_look_target_to_mat(hom),
].flatMap(f => [f(false), f(true)])
].join('\n\n') + '\n';

Expand Down
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