add standard transforms (450f0481) · Commits · github_fork / Clip

core/vmath.cc

+92 −2

Original line number	Diff line number	Diff line
		@@ -19,6 +19,8 @@

		namespace fviz {

		constexpr double TAU = M_PI * 2;

		vec2::vec2() :
		x(0.0),
		y(0.0) {}
		@@ -29,12 +31,48 @@ vec2::vec2(
		x(_x),
		y(_y) {}

		double vec2_magnitude(const vec2& v) {
		vec2::vec2(
		const vec3& v) :
		x(v.x),
		y(v.y) {}

		vec3::vec3() :
		x(0.0),
		y(0.0),
		z(0.0) {}

		vec3::vec3(
		double _x,
		double _y,
		double _z) :
		x(_x),
		y(_y),
		z(_z) {}

		vec3::vec3(
		const vec2& v,
		double _z) :
		x(v.x),
		y(v.y),
		z(_z) {}

		mat3::mat3() :
		a(0.0),
		b(0.0),
		c(0.0),
		d(0.0),
		e(0.0),
		f(0.0),
		g(0.0),
		h(0.0),
		i(0.0) {}

		double magnitude(const vec2& v) {
		return sqrt(v.x * v.x + v.y * v.y);
		}

		vec2 normalize(const vec2& v) {
		auto m = vec2_magnitude(v);
		auto m = magnitude(v);
		return {v.x / m, v.y / m};
		}

		@@ -50,6 +88,29 @@ vec2 mul(const vec2& v, double s) {
		return {v.x * s, v.y * s};
		}

		mat3 mul(const mat3& a, const mat3& b) {
		mat3 m;

		m.a = a.a * b.a + a.b * b.d + a.c * b.g;
		m.b = a.a * b.b + a.b * b.e + a.c * b.h;
		m.c = a.a * b.c + a.b * b.f + a.c * b.i;
		m.d = a.d * b.a + a.e * b.d + a.f * b.g;
		m.e = a.d * b.b + a.e * b.e + a.f * b.h;
		m.f = a.d * b.c + a.e * b.f + a.f * b.i;
		m.g = a.g * b.a + a.h * b.d + a.i * b.g;
		m.h = a.g * b.b + a.h * b.e + a.i * b.h;
		m.i = a.g * b.c + a.h * b.f + a.i * b.i;

		return m;
		}

		vec3 mul(const mat3& m, const vec3& v) {
		return vec3(
		m.a * v.x + m.b * v.y + m.c * v.z,
		m.d * v.x + m.e * v.y + m.f * v.z,
		m.g * v.x + m.h * v.y + m.i * v.z);
		}

		double dot(const vec2& a, const vec2& b) {
		return a.x * b.x + a.y * b.y;
		}
		@@ -69,6 +130,35 @@ vec2 mean(const vec2* v, size_t v_len) {
		return mul(m, 1.0 / v_len);
		}

		mat3 rotate2(double angle) {
		double angle_tau = (-angle / 360) * TAU;
		mat3 m;
		m.a = cos(angle_tau);
		m.b = sin(angle_tau) * -1;
		m.d = sin(angle_tau);
		m.e = cos(angle_tau);
		m.i = 1.0;
		return m;
		}

		mat3 scale2(const vec2& s) {
		mat3 m;
		m.a = s.x;
		m.e = s.y;
		m.i = 1.0;
		return m;
		}

		mat3 translate2(const vec2& t) {
		mat3 m;
		m.a = 1.0;
		m.e = 1.0;
		m.i = 1.0;
		m.c = t.x;
		m.f = t.y;
		return m;
		}

		void sort_cw(vec2* v, size_t v_len) {
		auto m = mean(v, v_len);

core/vmath.h

+68 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,9 @@
		#include <iostream>

		namespace fviz {
		struct vec2;
		struct vec3;


		/**
		* A two-dimensional vector of the following form:
		@@ -29,8 +32,47 @@ namespace fviz {
		struct vec2 {
		vec2();
		vec2(double x, double y);
		explicit vec2(const vec3& v);
		double x;
		double y;
		};

		/**
		* A three-dimensional vector of the following form:
		*
		* \| X \|
		* \| Y \|
		* \| Z \|
		*
		*/
		struct vec3 {
		vec3();
		vec3(double x, double y, double z);
		vec3(const vec2& v, double z);
		double x;
		double y;
		double z;
		};

		/**
		* A 3x3 matrix of the following form:
		*
		* \| A B C \|
		* \| D E F \|
		* \| G H I \|
		*
		*/
		struct mat3 {
		mat3();
		double a;
		double d;
		double g;
		double b;
		double e;
		double h;
		double c;
		double f;
		double i;
		};

		/**
		@@ -48,6 +90,16 @@ vec2 sub(const vec2& a, const vec2& b);
		*/
		vec2 mul(const vec2& v, double s);

		/**
		* Multiply a 3x3 matrix with a 3x3 matrix
		*/
		mat3 mul(const mat3& a, const mat3& b);

		/**
		* Multiply a 3x3 matrix with a three-dimensional vector
		*/
		vec3 mul(const mat3& m, const vec3& v);

		/**
		* Compute the dot (scalar) product of two vectors
		*/
		@@ -75,6 +127,22 @@ vec2 normalize(const vec2& v);
		*/
		vec2 mean(const vec2* v, size_t v_len);

		/**
		* Create a 2D "rotation matrix" that rotates `angle` degrees clockwise around
		* origin
		*/
		mat3 rotate2(double angle);

		/**
		* Create a 2D "scale matrix"
		*/
		mat3 scale2(const vec2& s);

		/**
		* Create a 2D "translation matrix"
		*/
		mat3 translate2(const vec2& t);

		/**
		* Sort an array of vec2 objects in clockwise order
		*/

tests/unit/test_graphics_vmath.cc

0 → 100644

+79 −0

Original line number	Diff line number	Diff line
		/**
		* This file is part of the "fviz" project
		* Copyright (c) 2018 Paul Asmuth
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/
		#include "graphics/brush.h"
		#include "graphics/color.h"
		#include "graphics/page_description.h"
		#include "graphics/text.h"
		#include "environment.h"
		#include "utils/fileutil.h"
		#include "unittest.h"

		using namespace fviz;

		void test_translate() {
		auto m = translate2({1.0, 1.0});
		auto v1 = vec3(5.0, 2.0, 1.0);
		auto v2 = mul(m, v1);
		EXPECT_FEQ(v2.x, 6.0);
		EXPECT_FEQ(v2.y, 3.0);
		}

		void test_scale() {
		auto m = scale2({3.0, 3.0});
		auto v1 = vec3(5.0, 2.0, 1.0);
		auto v2 = mul(m, v1);
		EXPECT_FEQ(v2.x, 15.0);
		EXPECT_FEQ(v2.y, 6.0);
		}

		void test_rotate() {
		{
		auto m = rotate2(90);
		auto v1 = vec3(0.0, 2.0, 1.0);
		auto v2 = mul(m, v1);
		EXPECT_FEQ(v2.x, 2.0);
		EXPECT_FEQ(v2.y, 0.0);
		}

		{
		auto m = rotate2(180);
		auto v1 = vec3(0.0, 2.0, 1.0);
		auto v2 = mul(m, v1);
		EXPECT_FEQ(v2.x, 0.0);
		EXPECT_FEQ(v2.y, -2.0);
		}

		{
		auto m = rotate2(270);
		auto v1 = vec3(0.0, 2.0, 1.0);
		auto v2 = mul(m, v1);
		EXPECT_FEQ(v2.x, -2.0);
		EXPECT_FEQ(v2.y, 0.0);
		}

		{
		auto m = rotate2(360);
		auto v1 = vec3(0.0, 2.0, 1.0);
		auto v2 = mul(m, v1);
		EXPECT_FEQ(v2.x, 0.0);
		EXPECT_FEQ(v2.y, 2.0);
		}
		}

		int main(int argc, char** argv) {
		test_translate();
		test_scale();
		test_rotate();
		}

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