| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| /** @file matrix.cc |
| * Implements simple matrix manipulation functions. |
| */ |
| |
| //----------------------------------------------------------------------------- |
| #include <stdlib.h> |
| #include <string.h> |
| #include "matrix.h" |
| #define deg_to_rad(x) (x * (M_PI / 180.0f)) |
| |
| void glhFrustumf2(Matrix_t mat, |
| GLfloat left, |
| GLfloat right, |
| GLfloat bottom, |
| GLfloat top, |
| GLfloat znear, |
| GLfloat zfar) { |
| float temp, temp2, temp3, temp4; |
| temp = 2.0f * znear; |
| temp2 = right - left; |
| temp3 = top - bottom; |
| temp4 = zfar - znear; |
| mat[0] = temp / temp2; |
| mat[1] = 0.0f; |
| mat[2] = 0.0f; |
| mat[3] = 0.0f; |
| mat[4] = 0.0f; |
| mat[5] = temp / temp3; |
| mat[6] = 0.0f; |
| mat[7] = 0.0f; |
| mat[8] = (right + left) / temp2; |
| mat[9] = (top + bottom) / temp3; |
| mat[10] = (-zfar - znear) / temp4; |
| mat[11] = -1.0f; |
| mat[12] = 0.0f; |
| mat[13] = 0.0f; |
| mat[14] = (-temp * zfar) / temp4; |
| mat[15] = 0.0f; |
| } |
| |
| void glhPerspectivef2(Matrix_t mat, |
| GLfloat fovyInDegrees, |
| GLfloat aspectRatio, |
| GLfloat znear, |
| GLfloat zfar) { |
| float ymax, xmax; |
| ymax = znear * tanf(fovyInDegrees * 3.14f / 360.0f); |
| xmax = ymax * aspectRatio; |
| glhFrustumf2(mat, -xmax, xmax, -ymax, ymax, znear, zfar); |
| } |
| |
| void identity_matrix(Matrix_t mat) { |
| memset(mat, 0, sizeof(Matrix_t)); |
| mat[0] = 1.0; |
| mat[5] = 1.0; |
| mat[10] = 1.0; |
| mat[15] = 1.0; |
| } |
| |
| void multiply_matrix(const Matrix_t a, const Matrix_t b, Matrix_t mat) { |
| // Generate to a temporary first in case the output matrix and input |
| // matrix are the same. |
| Matrix_t out; |
| |
| out[0] = a[0] * b[0] + a[4] * b[1] + a[8] * b[2] + a[12] * b[3]; |
| out[1] = a[1] * b[0] + a[5] * b[1] + a[9] * b[2] + a[13] * b[3]; |
| out[2] = a[2] * b[0] + a[6] * b[1] + a[10] * b[2] + a[14] * b[3]; |
| out[3] = a[3] * b[0] + a[7] * b[1] + a[11] * b[2] + a[15] * b[3]; |
| |
| out[4] = a[0] * b[4] + a[4] * b[5] + a[8] * b[6] + a[12] * b[7]; |
| out[5] = a[1] * b[4] + a[5] * b[5] + a[9] * b[6] + a[13] * b[7]; |
| out[6] = a[2] * b[4] + a[6] * b[5] + a[10] * b[6] + a[14] * b[7]; |
| out[7] = a[3] * b[4] + a[7] * b[5] + a[11] * b[6] + a[15] * b[7]; |
| |
| out[8] = a[0] * b[8] + a[4] * b[9] + a[8] * b[10] + a[12] * b[11]; |
| out[9] = a[1] * b[8] + a[5] * b[9] + a[9] * b[10] + a[13] * b[11]; |
| out[10] = a[2] * b[8] + a[6] * b[9] + a[10] * b[10] + a[14] * b[11]; |
| out[11] = a[3] * b[8] + a[7] * b[9] + a[11] * b[10] + a[15] * b[11]; |
| |
| out[12] = a[0] * b[12] + a[4] * b[13] + a[8] * b[14] + a[12] * b[15]; |
| out[13] = a[1] * b[12] + a[5] * b[13] + a[9] * b[14] + a[13] * b[15]; |
| out[14] = a[2] * b[12] + a[6] * b[13] + a[10] * b[14] + a[14] * b[15]; |
| out[15] = a[3] * b[12] + a[7] * b[13] + a[11] * b[14] + a[15] * b[15]; |
| |
| memcpy(mat, out, sizeof(Matrix_t)); |
| } |
| |
| void rotate_x_matrix(GLfloat x_rad, Matrix_t mat) { |
| identity_matrix(mat); |
| mat[5] = cosf(x_rad); |
| mat[6] = -sinf(x_rad); |
| mat[9] = -mat[6]; |
| mat[10] = mat[5]; |
| } |
| |
| void rotate_y_matrix(GLfloat y_rad, Matrix_t mat) { |
| identity_matrix(mat); |
| mat[0] = cosf(y_rad); |
| mat[2] = sinf(y_rad); |
| mat[8] = -mat[2]; |
| mat[10] = mat[0]; |
| } |
| |
| void rotate_z_matrix(GLfloat z_rad, Matrix_t mat) { |
| identity_matrix(mat); |
| mat[0] = cosf(z_rad); |
| mat[1] = sinf(z_rad); |
| mat[4] = -mat[1]; |
| mat[5] = mat[0]; |
| } |
| |
| void rotate_matrix(GLfloat x_deg, GLfloat y_deg, GLfloat z_deg, Matrix_t mat) { |
| GLfloat x_rad = (GLfloat) deg_to_rad(x_deg); |
| GLfloat y_rad = (GLfloat) deg_to_rad(y_deg); |
| GLfloat z_rad = (GLfloat) deg_to_rad(z_deg); |
| |
| Matrix_t x_matrix; |
| Matrix_t y_matrix; |
| Matrix_t z_matrix; |
| |
| rotate_x_matrix(x_rad, x_matrix); |
| rotate_y_matrix(y_rad, y_matrix); |
| rotate_z_matrix(z_rad, z_matrix); |
| |
| Matrix_t xy_matrix; |
| multiply_matrix(y_matrix, x_matrix, xy_matrix); |
| multiply_matrix(z_matrix, xy_matrix, mat); |
| } |
| |
| void translate_matrix(GLfloat x, GLfloat y, GLfloat z, Matrix_t mat) { |
| identity_matrix(mat); |
| mat[12] += x; |
| mat[13] += y; |
| mat[14] += z; |
| } |