blob: 19c26c85bf896d2e2bfd687ef3b527f9ca59ffa7 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
;;; guile-2d
;;; Copyright (C) 2013 David Thompson <dthompson2@worcester.edu>
;;;
;;; Guile-2d is free software: you can redistribute it and/or modify it
;;; under the terms of the GNU Lesser General Public License as
;;; published by the Free Software Foundation, either version 3 of the
;;; License, or (at your option) any later version.
;;;
;;; Guile-2d is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;;; Lesser General Public License for more details.
;;;
;;; You should have received a copy of the GNU Lesser General Public
;;; License along with this program. If not, see
;;; <http://www.gnu.org/licenses/>.
;;; Commentary:
;;
;; Textures and texture regions are high level wrappers over OpenGL
;; textures.
;;
;;; Code:
(define-module (2d texture)
#:use-module (srfi srfi-9)
#:use-module (srfi srfi-42)
#:use-module (figl gl)
#:use-module (2d wrappers gl)
#:use-module (2d wrappers freeimage)
#:use-module (2d helpers)
#:export (make-texture
make-texture-region
load-texture
texture?
texture-region?
texture-id
texture-width
texture-height
texture-s1
texture-t1
texture-s2
texture-t2
surface->texture
draw-texture
split-texture))
;;;
;;; Textures
;;;
;; The <texture> object is a simple wrapper around an OpenGL texture
;; id.
(define-record-type <texture>
(%make-texture id parent width height s1 t1 s2 t2)
texture?
(id texture-id)
(parent texture-parent)
(width texture-width)
(height texture-height)
(s1 texture-s1)
(t1 texture-t1)
(s2 texture-s2)
(t2 texture-t2))
(define (texture-region? texture)
(texture? (texture-parent texture)))
(define (make-texture id parent width height s1 t1 s2 t2)
(let ((texture (%make-texture id parent width height s1 t1 s2 t2)))
(texture-guardian texture)
texture))
(define (make-texture-region texture x y width height)
"Creates a new texture region given a texture and a pixel region."
(let* ((w (texture-width texture))
(h (texture-height texture)))
(make-texture (texture-id texture)
texture
width
height
(/ x w)
(/ y h)
(/ (+ x width) w)
(/ (+ y height) h))))
;; Use a guardian and an after GC hook that ensures that OpenGL
;; textures are deleted when texture objects are GC'd.
(define texture-guardian (make-guardian))
(define (reap-textures)
(let loop ((texture (texture-guardian)))
(when texture
;; Do not reap texture regions
(unless (texture-region? texture)
;; When attempting to reap structures upon guile exit, the
;; dynamic pointer to gl-delete-textures becomes invalid. So, we
;; ignore the error and move on.
(catch 'misc-error
(lambda () (gl-delete-texture (texture-id texture)))
(lambda (key . args) #f)))
(loop (texture-guardian)))))
(add-hook! after-gc-hook reap-textures)
(define (bitmap->texture bitmap)
"Translates a freeimage bitmap into an OpenGL texture."
(let ((texture-id (gl-generate-texture))
(pixels (freeimage-get-bits bitmap)))
(with-gl-bind-texture (texture-target texture-2d) texture-id
;; Use "nearest" scaling method so that pixel art doesn't become
;; blurry when scaled.
(gl-texture-parameter (texture-target texture-2d)
(texture-parameter-name texture-min-filter)
(texture-min-filter nearest))
(gl-texture-parameter (texture-target texture-2d)
(texture-parameter-name texture-mag-filter)
(texture-mag-filter nearest))
(gl-texture-image-2d (texture-target texture-2d)
0
(pixel-format rgba)
(freeimage-get-width bitmap)
(freeimage-get-height bitmap)
0
(version-1-2 bgra)
(color-pointer-type unsigned-byte)
pixels))
(make-texture texture-id
#f
(freeimage-get-width bitmap)
(freeimage-get-height bitmap)
0 0 1 1)))
(define (load-bitmap filename)
;; Throw an error if image file does not exist or else we will
;; segfault later.
(unless (file-exists? filename)
(throw 'image-not-found filename))
;; Load image and convert it to 32 bit color.
(let* ((image-type (freeimage-get-file-type filename))
(bitmap (freeimage-load image-type filename))
(32bit-bitmap (freeimage-convert-to-32-bits bitmap)))
(freeimage-unload bitmap)
32bit-bitmap))
(define (load-texture filename)
"Loads a texture from a file."
(let* ((bitmap (load-bitmap filename))
(texture (bitmap->texture bitmap)))
(freeimage-unload bitmap)
texture))
(define* (draw-texture texture x y #:optional (color #xffffffff))
"Renders a textured quad in GL immediate mode."
(let* ((x2 (+ x (texture-width texture)))
(y2 (+ y (texture-height texture)))
(color (rgba->gl-color color))
(r (vector-ref color 0))
(g (vector-ref color 1))
(b (vector-ref color 2))
(a (vector-ref color 3))
(s1 (texture-s1 texture))
(t1 (texture-t1 texture))
(s2 (texture-s2 texture))
(t2 (texture-t2 texture)))
(with-gl-bind-texture (texture-target texture-2d) (texture-id texture)
(gl-begin (begin-mode quads)
(gl-color r g b a)
(gl-texture-coordinates s1 t1)
(gl-vertex x y)
(gl-texture-coordinates s1 t2)
(gl-vertex x y2)
(gl-texture-coordinates s2 t2)
(gl-vertex x2 y2)
(gl-texture-coordinates s2 t1)
(gl-vertex x2 y)))))
(define* (split-texture texture width height #:optional #:key
(margin 0) (spacing 0))
"Splits a texture into a vector of texture regions of width x height
size."
(define (build-tile tx ty)
(let* ((x (+ (* tx (+ width spacing)) margin))
(y (+ (* ty (+ height spacing)) margin)))
(make-texture-region texture x y width height)))
(let* ((tw (texture-width texture))
(th (texture-height texture))
(rows (/ (- tw margin) (+ width spacing)))
(columns (/ (- tw margin) (+ height spacing))))
(vector-ec (: y rows) (: x columns) (build-tile x y))))
|
