From 2ef4c41b14223e2b4c871acd5465f4641e527fb1 Mon Sep 17 00:00:00 2001 From: Artem Zyktin Date: Tue, 2 Jun 2026 06:02:50 +0800 Subject: [PATCH] Update readme --- README.md | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/README.md b/README.md index d8cdddd..c146bad 100644 --- a/README.md +++ b/README.md @@ -19,7 +19,7 @@ BSD 3-Clause License. Copyright (c) 2026 Artem Zyktin. See [LICENSE.txt](LICENSE - Expression-template engine: nodes are lazy and evaluated on assignment. - C++20 concepts (`expression`, `vec_expr`, `scalar_expr`) enforce type safety at compile time. - Storage policy: small trivially-copyable nodes are stored by value, larger ones by `const&`, which also avoids dangling references to temporary sub-expressions. -- Operations: `+`, `-`, `*` (scalar), `/` (by scalar), `dot3`, `cross3`, `norm3`, `magnitude3`, `==`, `approx_eq`, and component accessors `x()`, `y()`, `z()`, `w()`. +- Operations: `+`, `-` (binary), `-` (unary negation), `*` (scalar), `/` (by scalar), `dot3`, `cross3`, `norm3`, `magnitude3`, `==`, `approx_eq`, and component accessors `x()`, `y()`, `z()`, `w()`. ## Requirements @@ -59,6 +59,11 @@ vec4 cr = cross3(a, b); // 3D cross product, result w = 0 vec4 n = norm3(a); // normalize xyz, w preserved float mag = magnitude3(a); // 3D length (ignores w) +// Negation (unary minus) - works on any expression node, stays lazy +vec4 neg_a = -a; +vec4 neg_expr = -(a + b); // Neg> - still lazy +float neg_d = -dot3(a, b); // Neg> - still scalar_expr + // Compound expression - evaluated lazily, no temporaries, fused on assignment vec4 result = norm3(a + b * 2.0f) * dot3(b, c) + c * 3.0f; ``` @@ -139,15 +144,16 @@ using tnvx_ref_or_value_t = | Node | Concept | Intrinsics | Notes | | ------------- | ------------- | ----------------------------------------------------------- | --------------------------------------------------------------------------- | +| `Neg` | vec / scalar | `_mm_xor_ps` (sign mask) | Unary negation; result is `vec_expr` when E is `vec_expr`, `scalar_expr` when E is `scalar_expr`; both stay lazy | | `Scalar` | `scalar_expr` | `_mm_set_ps1` | Broadcasts a `float` to all 4 lanes | | `Add` | `vec_expr` | `_mm_add_ps` | | | `Sub` | `vec_expr` | `_mm_sub_ps` | | | `Mul` | vec / scalar | `_mm_mul_ps` | Scalar multiply only (no component-wise `vec * vec`). Operands may be vector×scalar, scalar×vector, or scalar×scalar; a scalar operand is a `float` or a scalar expression | | `Div` | `vec_expr` | `_mm_div_ps` | Vector divided by a scalar (`float`) | -| `Dot3` | `scalar_expr` | `_mm_dp_ps` (mask `0x7F`) | 3-component dot (ignores w), broadcast to all lanes; convertible to `float` | +| `Dot3` | `scalar_expr` | `_mm_mul_ps` + shuffles + `_mm_add_ss` | 3-component dot (ignores w), broadcast to all lanes; convertible to `float` | | `Cross3` | `vec_expr` | `_mm_shuffle_ps` + `_mm_mul_ps` + `_mm_sub_ps` | 3-component cross product; result `w = 0` | -| `Norm3` | `vec_expr` | `_mm_dp_ps` + `_mm_sqrt_ps` + `_mm_div_ps` + `_mm_blend_ps` | Normalizes xyz by the 3D magnitude; preserves w | -| `Magn3` | `scalar_expr` | `_mm_sqrt_ps(_mm_dp_ps(..., 0x7F))` | 3-component length (ignores w), broadcast; convertible to `float` | +| `Norm3` | `vec_expr` | `dot3` + `_mm_sqrt_ps` + `_mm_div_ps` + `_mm_blend_ps` | Normalizes xyz by the 3D magnitude; preserves w | +| `Magn3` | `scalar_expr` | `_mm_sqrt_ps` + `dot3(v,v)` | 3-component length (ignores w), broadcast; convertible to `float` | Comparison helpers (free functions in `tnvx`, backed by `tnvx::detail`): @@ -185,7 +191,7 @@ Build output is written to `bin//x64//output/`. ## Running Tests -The test suite uses Google Test (vendored in `thirdparty/gtest/`) and currently covers 27 cases: +The test suite uses Google Test (vendored in `thirdparty/gtest/`) and currently covers 34 cases: | Category | Tests | | -------------------- | ---------------------------------------------------------------------------------------------------------- | @@ -193,6 +199,7 @@ The test suite uses Google Test (vendored in `thirdparty/gtest/`) and currently | Compound expressions | `mixed_type_add`, `expression_a`, `expression_b`, `expression_c`, `expression_d`, `expression_from_temporaries` | | Math properties | `cross_anticommutative`, `dot_commutative`, `norm_magnitude`, `dot_perpendicular`, `cross_parallel`, `w_is_zero_with_nonzero_input_w`, `preserves_nontrivial_w`, `zero_vector_is_nan` | | Type system | `dot3_times_literal_collapses`, `magnitude3_times_literal_collapses` | +| Unary negation | `neg_basic`, `neg_zero`, `neg_double`, `neg_compound`, `neg_expression`, `neg_scalar_stays_lazy`, `neg_scalar_in_expression` | Build and run `tenvex_tests` from the generated project or makefile.