Base/core/src-c/matrix.c

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#include <librr/linear_algebra.h>
#include <math.h>
rr_mat2f_s rr_identity_mat2f()
{
rr_mat2f_s matrix;
matrix.values[0][0] = 1.0f;
matrix.values[0][1] = 0.0f;
matrix.values[1][0] = 0.0f;
matrix.values[1][1] = 1.0f;
return matrix;
}
rr_mat3f_s rr_identity_mat3f()
{
rr_mat3f_s matrix;
matrix.values[0][0] = 1.0f;
matrix.values[0][1] = 0.0f;
matrix.values[0][2] = 0.0f;
matrix.values[1][0] = 0.0f;
matrix.values[1][1] = 1.0f;
matrix.values[1][2] = 0.0f;
matrix.values[2][0] = 0.0f;
matrix.values[2][1] = 0.0f;
matrix.values[2][2] = 1.0f;
return matrix;
}
rr_mat4f_s rr_identity_mat4f()
{
rr_mat4f_s matrix;
matrix.values[0][0] = 1.0f;
matrix.values[0][1] = 0.0f;
matrix.values[0][2] = 0.0f;
matrix.values[0][3] = 0.0f;
matrix.values[1][0] = 0.0f;
matrix.values[1][1] = 1.0f;
matrix.values[1][2] = 0.0f;
matrix.values[1][3] = 0.0f;
matrix.values[2][0] = 0.0f;
matrix.values[2][1] = 0.0f;
matrix.values[2][2] = 1.0f;
matrix.values[2][3] = 0.0f;
matrix.values[3][0] = 0.0f;
matrix.values[3][1] = 0.0f;
matrix.values[3][2] = 0.0f;
matrix.values[3][3] = 1.0f;
return matrix;
}
rr_mat4f_s rr_mat4f_multiply(rr_mat4f_s first, rr_mat4f_s second)
{
rr_mat4f_s result;
usz_t row = 0;
usz_t column = 0;
usz_t index = 0;
while(row < 4)
{
column = 0;
while(column < 4)
{
result.values[column][row] = 0.0f;
index = 0;
while(index < 4)
{
result.values[column][row] += first.values[column][index] * second.values[index][row];
++index;
}
++column;
}
++row;
}
return result;
}
rr_vec4f_s rr_mat4f_multiply_vec4f(rr_mat4f_s matrix, rr_vec4f_s vector)
{
rr_vec4f_s result;
result.x = matrix.values[0][0] * vector.x;
result.x += matrix.values[0][1] * vector.y;
result.x += matrix.values[0][2] * vector.z;
result.x += matrix.values[0][3] * vector.w;
result.y = matrix.values[1][0] * vector.x;
result.y += matrix.values[1][1] * vector.y;
result.y += matrix.values[1][2] * vector.z;
result.y += matrix.values[1][3] * vector.w;
result.z = matrix.values[2][0] * vector.x;
result.z += matrix.values[2][1] * vector.y;
result.z += matrix.values[2][2] * vector.z;
result.z += matrix.values[2][3] * vector.w;
result.w = matrix.values[3][0] * vector.x;
result.w += matrix.values[3][1] * vector.y;
result.w += matrix.values[3][2] * vector.z;
result.w += matrix.values[3][3] * vector.w;
return result;
}
void rr_mat4f_translate(rr_mat4f_s *matrix, rr_vec3f_s xyz)
{
matrix->values[3][0] = xyz.x;
matrix->values[3][1] = xyz.y;
matrix->values[3][2] = xyz.z;
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}
rr_mat4f_s rr_mat4f_rotate_x(float radians)
{
float sine = sinf(radians);
float cosine = cosf(radians);
rr_mat4f_s matrix;
matrix.values[1][1] = cosine;
matrix.values[1][2] = -sine;
matrix.values[2][1] = sine;
matrix.values[2][2] = -cosine;
return matrix;
}
rr_mat4f_s rr_mat4f_rotate_y(float radians)
{
float sine = sinf(radians);
float cosine = cosf(radians);
rr_mat4f_s matrix;
matrix.values[0][0] = cosine;
matrix.values[0][2] = sine;
matrix.values[2][0] = -sine;
matrix.values[2][2] = cosine;
return matrix;
}
rr_mat4f_s rr_mat4f_rotate_z(float radians)
{
float sine = sinf(radians);
float cosine = cosf(radians);
rr_mat4f_s matrix;
matrix.values[0][0] = cosine;
matrix.values[0][1] = -sine;
matrix.values[1][0] = sine;
matrix.values[1][1] = cosine;
return matrix;
}
rr_mat4f_s rr_mat4f_rotate_xyz(float x_rad, float y_rad, float z_rad)
{
rr_mat4f_s matrix = rr_mat4f_rotate_z(z_rad);
matrix = rr_mat4f_multiply(matrix, rr_mat4f_rotate_y(y_rad));
matrix = rr_mat4f_multiply(matrix, rr_mat4f_rotate_x(x_rad));
return matrix;
}
rr_mat4f_s rr_mat4f_perspective(float fov, float near_plane, float far_plane, float aspect_ratio)
{
float a = tanf(fov / 2.0f) * near_plane;
float planes_sum = far_plane + near_plane;
float planes_range = far_plane - near_plane;
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rr_mat4f_s matrix;
matrix.values[0][0] = 1 / aspect_ratio;
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matrix.values[0][1] = 0.0f;
matrix.values[0][2] = 0.0f;
matrix.values[0][3] = 0.0f;
matrix.values[1][0] = 0.0f;
matrix.values[1][1] = aspect_ratio;
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matrix.values[1][2] = 0.0f;
matrix.values[1][3] = 0.0f;
matrix.values[2][0] = 0.0f;
matrix.values[2][1] = 0.0f;
matrix.values[2][2] = -(planes_sum / planes_range);
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matrix.values[2][3] = -1.0f;
matrix.values[3][0] = 0.0f;
matrix.values[3][1] = 0.0f;
matrix.values[3][2] = -(2 * planes_sum / planes_range);
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matrix.values[3][3] = 0.0f;
return matrix;
}