moved linear algebra code to core/

core/linear.c

@@ -0,0 +1,205 @@
+/* SPDX-License-Identifier:BSD-3-Clause */
+#include "linear.h"
+
+float vec2_dot(vec2 a, vec2 b)
+{
+	float result = 0.0f;
+	for (int i = 0; i < 2; i++) {
+		result += a[i] * b[i];
+	}
+
+	return result;
+}
+
+float
+vec3_dot(vec3 a, vec3 b)
+{
+	float result = 0.0f;
+	for (int i = 0; i < 3; i++) {
+		result += a[i] * b[i];
+	}
+
+	return result;
+}
+
+float
+vec4_dot(vec4 a, vec4 b)
+{
+	float result = 0.0f;
+	for (int i = 0; i < 4; i++) {
+		result += a[i] * b[i];
+	}
+
+	return result;
+}
+
+void
+vec3_cross(vec3 dest, vec3 a, vec3 b)
+{
+	vec3 res = {0};
+	res[0] = a[1] * b[2] - a[2] * b[1];
+	res[1] = a[2] * b[0] - a[0] * b[2];
+	res[2] = a[0] * b[1] - a[1] * b[0];
+	memcpy(dest, res, sizeof(vec3));
+}
+
+void
+mat4_perspective(mat4 dest, float fov, float aspect, float near, float far)
+{
+	mat4 perspective = {
+		{1.0f / (aspect * tan(fov / 2.0f)), 0.0f, 0.0f, 0.0f},
+		{0.0f, 1.0f / tan(fov / 2.0f), 0.0f, 0.0f},
+		{0.0f, 0.0f, -((far + near) / (far - near)), -((2 * far * near) / (far - near))},
+		{0.0f, 0.0f, -1.0f, 0.0f}
+	};
+
+	memcpy(dest, perspective, sizeof(mat4));
+}
+
+void
+mat4_lookat(mat4 dest, vec3 eye, vec3 target, vec3 up)
+{
+	vec3 target_cpy = {0};
+	memcpy(target_cpy, target, sizeof(vec3));
+	vec3_sub(target_cpy, target_cpy, eye);
+
+	vec3 zaxis = {0};
+	vec3_normalize(zaxis, target_cpy);
+
+	vec3 zaxis_cpy = {0};
+	memcpy(zaxis_cpy, zaxis, sizeof(vec3));
+	vec3_cross(zaxis_cpy, zaxis, up);
+
+	vec3 xaxis = {0};
+	vec3_normalize(xaxis, zaxis_cpy);
+
+	vec3 yaxis = {0};
+	vec3_cross(yaxis, xaxis, zaxis);
+
+	zaxis[0] = -zaxis[0];
+	zaxis[1] = -zaxis[1];
+	zaxis[2] = -zaxis[2];
+
+	mat4 view = {
+		{xaxis[0], xaxis[1], xaxis[2], -vec3_dot(xaxis, eye)},
+		{yaxis[0], yaxis[1], yaxis[2], -vec3_dot(yaxis, eye)},
+		{zaxis[0], zaxis[1], zaxis[2], -vec3_dot(zaxis, eye)},
+		{0.0f, 0.0f, 0.0f, 1.0f}
+	};
+
+	memcpy(dest, view, sizeof(mat4));
+}
+
+void
+vec2_sub(vec2 dest, vec2 a, vec2 b)
+{
+	vec2 res = {0};
+	for (int i = 0; i < 2; i++)
+		res[i] = a[i] - b[i];
+	memcpy(dest, res, sizeof(vec2));
+}
+
+void
+vec3_sub(vec3 dest, vec3 a, vec3 b)
+{
+	vec3 res = {0};
+	for (int i = 0; i < 3; i++)
+		res[i] = a[i] - b[i];
+	memcpy(dest, res, sizeof(vec3));
+}
+
+void
+vec4_sub(vec4 dest, vec4 a, vec4 b)
+{
+	vec4 res = {0};
+	for (int i = 0; i < 4; i++)
+		res[i] = a[i] - b[i];
+	memcpy(dest, res, sizeof(vec4));
+}
+
+void
+vec2_add(vec2 dest, vec2 a, vec2 b)
+{
+	vec2 res = {0};
+	for (int i = 0; i < 2; i++)
+		res[i] = a[i] + b[i];
+	memcpy(dest, res, sizeof(vec2));
+}
+
+void
+vec3_add(vec3 dest, vec3 a, vec3 b)
+{
+	vec3 res = {0};
+	for (int i = 0; i < 3; i++)
+		res[i] = a[i] + b[i];
+	memcpy(dest, res, sizeof(vec3));
+}
+
+void
+vec4_add(vec4 dest, vec4 a, vec4 b)
+{
+	vec4 res = {0};
+	for (int i = 0; i < 4; i++)
+		res[i] = a[i] + b[i];
+	memcpy(dest, res, sizeof(vec4));
+}
+
+void
+vec2_normalize(vec2 dest, vec2 a)
+{
+	vec2 res = {0};
+	memcpy(res, a, sizeof(vec2));
+	float w = sqrt(a[0] * a[0] + a[1] * a[1]);
+	res[0] /= w;
+	res[1] /= w;
+	memcpy(dest, res, sizeof(vec2));
+}
+
+void
+vec3_normalize(vec3 dest, vec3 a)
+{
+	vec3 res = {0};
+	memcpy(res, a, sizeof(vec3));
+	float w = sqrt(a[0] * a[0] + a[1] * a[1] + a[2] * a[2]);
+	res[0] /= w;
+	res[1] /= w;
+	res[2] /= w;
+	memcpy(dest, res, sizeof(vec3));
+}
+
+void
+vec4_normalize(vec4 dest, vec4 a)
+{
+	vec4 res = {0};
+	memcpy(res, a, sizeof(vec4));
+	float w = sqrt(a[0] * a[0] + a[1] * a[1] + a[2] * a[2]);
+	res[0] /= w;
+	res[1] /= w;
+	res[2] /= w;
+	res[3] /= w;
+	memcpy(dest, res, sizeof(vec4));
+}
+
+void
+vec2_scale(vec2 dest, vec2 a, float scale)
+{
+	memcpy(dest, a, sizeof(vec2));
+	for (int i = 0; i < 2; i++)
+		dest[i] *= scale;
+}
+
+void
+vec3_scale(vec3 dest, vec3 a, float scale)
+{
+	memcpy(dest, a, sizeof(vec3));
+	for (int i = 0; i < 3; i++)
+		dest[i] *= scale;
+}
+
+void
+vec4_scale(vec4 dest, vec4 a, float scale)
+{
+	memcpy(dest, a, sizeof(vec4));
+	for (int i = 0; i < 4; i++)
+		dest[i] *= scale;
+}

core/linear.h

@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier:BSD-3-Clause */
+#ifndef LINEAR_H
+#define LINEAR_H
+
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include "../types.h"
+
+#define PI 3.14159265358979323846
+#define RAD(deg) deg * (PI / 180.0f)
+#define DEG(rad) rad * (180.0f / PI)
+
+typedef f32 vec2[2];
+typedef f32 vec3[3];
+typedef f32 vec4[4];
+
+typedef f32 mat2[2][2];
+typedef f32 mat3[3][3];
+typedef f32 mat4[4][4];
+
+f32 vec2_dot(vec2 a, vec2 b);
+f32 vec3_dot(vec3 a, vec3 b);
+f32 vec4_dot(vec4 a, vec4 b);
+
+void vec2_sub(vec2 dest, vec2 a, vec2 b);
+void vec3_sub(vec3 dest, vec3 a, vec3 b);
+void vec4_sub(vec4 dest, vec4 a, vec4 b);
+
+void vec2_add(vec2 dest, vec2 a, vec2 b);
+void vec3_add(vec3 dest, vec3 a, vec3 b);
+void vec4_add(vec4 dest, vec4 a, vec4 b);
+
+void vec3_cross(vec3 dest, vec3 a, vec3 b);
+
+void vec2_normalize(vec2 dest, vec2 a);
+void vec3_normalize(vec3 dest, vec3 a);
+void vec4_normalize(vec4 dest, vec4 a);
+
+void vec2_scale(vec2 dest, vec2 a, f32 scale);
+void vec3_scale(vec3 dest, vec3 a, f32 scale);
+void vec4_scale(vec4 dest, vec4 a, f32 scale);
+
+void mat4_perspective(mat4 dest, f32 fov, f32 aspect, f32 near, f32 far);
+void mat4_lookat(mat4 dest, vec3 eye, vec3 target, vec3 up);
+
+#endif