Mercurial > touhou
comparison pytouhou/utils/maths.pyx @ 412:5fe6cd6ceb48
Refactor the maths functions out of Renderer.
| author | Emmanuel Gil Peyrot <linkmauve@linkmauve.fr> |
|---|---|
| date | Wed, 12 Jun 2013 18:30:08 +0200 |
| parents | |
| children | 878273a984c4 |
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| 411:2428296cccab | 412:5fe6cd6ceb48 |
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| 1 # -*- encoding: utf-8 -*- | |
| 2 ## | |
| 3 ## Copyright (C) 2013 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr> | |
| 4 ## | |
| 5 ## This program is free software; you can redistribute it and/or modify | |
| 6 ## it under the terms of the GNU General Public License as published | |
| 7 ## by the Free Software Foundation; version 3 only. | |
| 8 ## | |
| 9 ## This program is distributed in the hope that it will be useful, | |
| 10 ## but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 11 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 12 ## GNU General Public License for more details. | |
| 13 ## | |
| 14 | |
| 15 from math import radians | |
| 16 from libc.math cimport tan | |
| 17 | |
| 18 from .matrix cimport Matrix | |
| 19 from .vector import Vector, normalize, cross, dot | |
| 20 | |
| 21 | |
| 22 cpdef ortho_2d(left, right, bottom, top): | |
| 23 mat = Matrix() | |
| 24 data = mat.data | |
| 25 data[0][0] = 2 / (right - left) | |
| 26 data[1][1] = 2 / (top - bottom) | |
| 27 data[2][2] = -1 | |
| 28 data[3][0] = -(right + left) / (right - left) | |
| 29 data[3][1] = -(top + bottom) / (top - bottom) | |
| 30 return mat | |
| 31 | |
| 32 | |
| 33 cpdef look_at(eye, center, up): | |
| 34 eye = Vector(eye) | |
| 35 center = Vector(center) | |
| 36 up = Vector(up) | |
| 37 | |
| 38 f = normalize(center - eye) | |
| 39 u = normalize(up) | |
| 40 s = normalize(cross(f, u)) | |
| 41 u = cross(s, f) | |
| 42 | |
| 43 return Matrix([[s[0], u[0], -f[0], 0], | |
| 44 [s[1], u[1], -f[1], 0], | |
| 45 [s[2], u[2], -f[2], 0], | |
| 46 [-dot(s, eye), -dot(u, eye), dot(f, eye), 1]]) | |
| 47 | |
| 48 | |
| 49 cpdef perspective(fovy, aspect, z_near, z_far): | |
| 50 top = tan(radians(fovy / 2)) * z_near | |
| 51 bottom = -top | |
| 52 left = -top * aspect | |
| 53 right = top * aspect | |
| 54 | |
| 55 mat = Matrix() | |
| 56 data = mat.data | |
| 57 data[0][0] = (2 * z_near) / (right - left) | |
| 58 data[1][1] = (2 * z_near) / (top - bottom) | |
| 59 data[2][2] = -(z_far + z_near) / (z_far - z_near) | |
| 60 data[2][3] = -1 | |
| 61 data[3][2] = -(2 * z_far * z_near) / (z_far - z_near) | |
| 62 data[3][3] = 0 | |
| 63 return mat | |
| 64 | |
| 65 | |
| 66 cpdef setup_camera(dx, dy, dz): | |
| 67 # Some explanations on the magic constants: | |
| 68 # 192. = 384. / 2. = width / 2. | |
| 69 # 224. = 448. / 2. = height / 2. | |
| 70 # 835.979370 = 224./math.tan(math.radians(15)) = (height/2.)/math.tan(math.radians(fov/2)) | |
| 71 # This is so that objects on the (O, x, y) plane use pixel coordinates | |
| 72 return look_at((192., 224., - 835.979370 * dz), | |
| 73 (192. + dx, 224. - dy, 0.), (0., -1., 0.)) |