Techneck/code/source-c/utility/matrix.c

#include <utility/math.h>

#include <math.h>

tc_mat4f_s tc_mat4f_zero()
{
    tc_mat4f_s              matrix;
    matrix.values[0][0]             = 0.0f;
    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]             = 0.0f;
    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]             = 0.0f;
    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]             = 0.0f;
    
    return matrix;
}

tc_mat4f_s tc_mat4f_identity()
{
    tc_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;
}

tc_mat3f_s tc_mat3f_identity()
{
    tc_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;
}

tc_mat4f_s tc_mat4f_multiply(tc_mat4f_s first, tc_mat4f_s second)
{
    tc_mat4f_s          result;
    
    u32_t               k, r, c;
	for(c = 0; c < 4; ++c)
	{
	    for(r = 0; r < 4; ++r)
	    {
	        result.values[c][r] = 0.f;
	        for(k=0; k<4; ++k)
	        {
		        result.values[c][r] += first.values[k][r] * second.values[c][k];
            }
		}
	}
	
	return result;
}



tc_mat4f_s tc_mat4_rotate_x(tc_mat4f_s matrix, float radians)
{
    tc_mat4f_s          rotation        = tc_mat4f_identity();
    rotation.values[1][1]               =  cosf(radians);
    rotation.values[1][2]               = -sinf(radians);
    rotation.values[2][1]               =  sinf(radians);
    rotation.values[2][2]               =  cosf(radians);
    
    return tc_mat4f_multiply(matrix, rotation);
}

tc_mat4f_s tc_mat4_rotate_y(tc_mat4f_s matrix, float radians)
{
    tc_mat4f_s          rotation        = tc_mat4f_identity();
    rotation.values[0][0]               =  cosf(radians);
    rotation.values[0][2]               =  sinf(radians);
    rotation.values[2][0]               = -sinf(radians);
    rotation.values[2][2]               =  cosf(radians);
    
    return tc_mat4f_multiply(matrix, rotation);
}

tc_mat4f_s tc_mat4_rotate_z(tc_mat4f_s matrix, float radians)
{
    tc_mat4f_s          rotation        = tc_mat4f_identity();
    rotation.values[0][0]               =  cosf(radians);
    rotation.values[0][1]               = -sinf(radians);
    rotation.values[1][0]               =  sinf(radians);
    rotation.values[1][1]               =  cosf(radians);
    
    return tc_mat4f_multiply(matrix, rotation);
}



tc_mat4f_s tc_mat4f_translate(tc_mat4f_s matrix, tc_vec3f_s translation)
{
    matrix.values[0][3]        += translation.x;
    matrix.values[1][3]        += translation.y;
    matrix.values[2][3]        += translation.z;
    
    return matrix;
}

tc_mat3f_s tc_mat3f_translate(tc_mat3f_s matrix, tc_vec3f_s translation)
{
    matrix.values[0][2]        += translation.x;
    matrix.values[1][2]        += translation.y;
    matrix.values[2][2]        += translation.z;
    
    return matrix;
}



tc_mat4f_s tc_mat4f_perspective(float fov, float aspect_ratio, float near, float far)
{
    float           range               = tanf(fov / 2) * near;
    float           scale_x             = (2 * near) / (range * aspect_ratio * 2);
    float           scale_y             = near / range;
    float           scale_z             = -(far + near) / (far - near);
    float           position_z          = -(2 * far * near) / (far - near);
    
    tc_mat4f_s      matrix              = tc_mat4f_zero();
    matrix.values[0][0]                 = scale_x;
    matrix.values[1][1]                 = scale_y;
    matrix.values[2][2]                 = scale_z;
    matrix.values[3][2]                 = -1.0f;
    matrix.values[2][3]                 = position_z;
    
    return matrix;
}