math: vector: Fix vec2-normalize and vec3-normalize.
[chickadee.git] / chickadee / render / texture.scm
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1;;; Chickadee Game Toolkit
2;;; Copyright © 2016 David Thompson <davet@gnu.org>
3;;;
4;;; Chickadee is free software: you can redistribute it and/or modify
5;;; it under the terms of the GNU General Public License as published
6;;; by the Free Software Foundation, either version 3 of the License,
7;;; or (at your option) any later version.
8;;;
9;;; Chickadee is distributed in the hope that it will be useful, but
10;;; WITHOUT ANY WARRANTY; without even the implied warranty of
11;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12;;; General Public License for more details.
13;;;
14;;; You should have received a copy of the GNU General Public License
15;;; along with this program. If not, see
16;;; <http://www.gnu.org/licenses/>.
17
18(define-module (chickadee render texture)
19 #:use-module (ice-9 format)
20 #:use-module (ice-9 match)
21 #:use-module (rnrs bytevectors)
22 #:use-module (srfi srfi-9)
23 #:use-module (srfi srfi-9 gnu)
51d3c475 24 #:use-module (system foreign)
98dc87a0 25 #:use-module (gl)
3879c714 26 #:use-module (gl enums)
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27 #:use-module (sdl2 surface)
28 #:use-module (oop goops)
2f4eab3c 29 #:use-module (chickadee math rect)
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30 #:use-module (chickadee render gl)
31 #:use-module (chickadee render gpu)
32 #:export (make-texture
fedd9bca 33 make-texture-region
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34 load-image
35 texture?
fedd9bca 36 texture-region?
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37 texture-null?
38 texture-id
39 texture-parent
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40 texture-min-filter
41 texture-mag-filter
42 texture-wrap-s
43 texture-wrap-t
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44 texture-x
45 texture-y
46 texture-width
47 texture-height
fedd9bca 48 texture-gl-rect
5896bde4 49 texture-gl-tex-rect
98dc87a0 50 null-texture
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51 texture-set!
52 texture-ref
98dc87a0 53
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54 texture-atlas
55 list->texture-atlas
56 split-texture
57 texture-atlas?
69d61338 58 texture-atlas-texture
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59 texture-atlas-ref))
60
61\f
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62;;;
63;;; Textures
64;;;
65
66;; The <texture> object is a simple wrapper around an OpenGL texture
67;; id.
68(define-record-type <texture>
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69 (%make-texture id parent min-filter mag-filter wrap-s wrap-t
70 x y width height gl-rect gl-tex-rect)
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71 texture?
72 (id texture-id)
fedd9bca 73 (parent texture-parent)
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74 (min-filter texture-min-filter)
75 (mag-filter texture-mag-filter)
76 (wrap-s texture-wrap-s)
c7d382fd 77 (wrap-t texture-wrap-t)
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78 (x texture-x)
79 (y texture-y)
80 (width texture-width)
81 (height texture-height)
82 (gl-rect texture-gl-rect)
83 (gl-tex-rect texture-gl-tex-rect))
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84
85(set-record-type-printer! <texture>
86 (lambda (texture port)
87 (format port
5896bde4 88 "#<texture region?: ~a x: ~d y: ~d width: ~d height: ~d min-filter: ~a mag-filter: ~a wrap-s: ~a wrap-t: ~a>"
fedd9bca 89 (texture-region? texture)
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90 (texture-x texture)
91 (texture-y texture)
92 (texture-width texture)
93 (texture-height texture)
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94 (texture-min-filter texture)
95 (texture-mag-filter texture)
96 (texture-wrap-s texture)
97 (texture-wrap-t texture))))
98
c7d382fd 99(define null-texture
5896bde4 100 (%make-texture 0 #f 'linear 'linear 'repeat 'repeat 0 0 0 0
fedd9bca 101 (make-rect 0.0 0.0 0.0 0.0) (make-rect 0.0 0.0 0.0 0.0)))
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102
103(define <<texture>> (class-of null-texture))
104
105(define (texture-null? texture)
106 "Return #t if TEXTURE is the null texture."
107 (eq? texture null-texture))
108
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109(define (texture-region? texture)
110 (texture? (texture-parent texture)))
111
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112(define (free-texture texture)
113 (gl-delete-texture (texture-id texture)))
114
115(define-method (gpu-finalize (texture <<texture>>))
116 (free-texture texture))
117
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118(define (make-apply-texture n)
119 (let ((texture-unit (+ (version-1-3 texture0) n)))
120 (lambda (texture)
121 (set-gl-active-texture texture-unit)
122 (gl-bind-texture (texture-target texture-2d)
123 (texture-id texture)))))
98dc87a0 124
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125(define *texture-states*
126 (let ((states (make-vector 32)))
127 (let loop ((i 0))
128 (if (< i 32)
129 (begin
130 (vector-set! states i (make-gpu-state (make-apply-texture i)
131 null-texture))
132 (loop (1+ i)))
133 states))))
134
135(define (texture-ref! n)
136 (gpu-state-ref (vector-ref *texture-states* n)))
137
138(define (texture-set! n texture)
139 (gpu-state-set! (vector-ref *texture-states* n) texture))
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140
141(define* (make-texture pixels width height #:key
142 (min-filter 'linear)
143 (mag-filter 'linear)
144 (wrap-s 'repeat)
145 (wrap-t 'repeat)
146 (format 'rgba))
147 "Translate the bytevector PIXELS into an OpenGL texture with
148dimensions WIDTHxHEIGHT where each pixel is in 32-bit RGBA format.
149The generated texture uses MIN-FILTER for downscaling and MAG-FILTER
150for upscaling. WRAP-S and WRAP-T are symbols that control how texture
151access is handled for texture coordinates outside the [0, 1] range.
152Allowed symbols are: repeat (the default), clamp, clamp-to-border,
153clamp-to-edge. FORMAT specifies the pixel format. Currently only
15432-bit RGBA format is supported."
155 (define (gl-wrap mode)
156 (match mode
157 ('repeat (texture-wrap-mode repeat))
158 ('clamp (texture-wrap-mode clamp))
159 ('clamp-to-border (texture-wrap-mode clamp-to-border-sgis))
160 ('clamp-to-edge (texture-wrap-mode clamp-to-edge-sgis))))
161
162 (let ((texture (gpu-guard
fedd9bca 163 (%make-texture (gl-generate-texture) #f
c7d382fd 164 min-filter mag-filter wrap-s wrap-t
5896bde4 165 0 0 width height
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166 (make-rect 0.0 0.0 width height)
167 (make-rect 0.0 0.0 1.0 1.0)))))
8152ddc9 168 (texture-set! 0 texture)
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169 (gl-texture-parameter (texture-target texture-2d)
170 (texture-parameter-name texture-min-filter)
171 (match min-filter
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172 ('nearest 9728)
173 ('linear 9729)))
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174 (gl-texture-parameter (texture-target texture-2d)
175 (texture-parameter-name texture-mag-filter)
176 (match mag-filter
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177 ('nearest 9728)
178 ('linear 9729)))
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179 (gl-texture-parameter (texture-target texture-2d)
180 (texture-parameter-name texture-wrap-s)
181 (gl-wrap wrap-s))
182 (gl-texture-parameter (texture-target texture-2d)
183 (texture-parameter-name texture-wrap-t)
184 (gl-wrap wrap-t))
185 (gl-texture-image-2d (texture-target texture-2d)
186 0 (pixel-format rgba) width height 0
187 (match format
188 ('rgba (pixel-format rgba)))
189 (color-pointer-type unsigned-byte)
51d3c475 190 (or pixels %null-pointer))
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191 texture))
192
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193(define (make-texture-region texture rect)
194 "Create a new texture region covering a section of TEXTURE defined
195by the bounding box RECT."
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196 (let* ((pw (texture-width texture))
197 (ph (texture-height texture))
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198 (x (rect-x rect))
199 (y (rect-y rect))
200 (w (rect-width rect))
201 (h (rect-height rect))
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202 (vert-rect (make-rect 0.0 0.0 w h))
203 (tex-rect (make-rect (/ x pw) (/ y ph) (/ w pw) (/ h ph))))
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204 (%make-texture (texture-id texture)
205 texture
206 (texture-min-filter texture)
207 (texture-mag-filter texture)
208 (texture-wrap-s texture)
209 (texture-wrap-t texture)
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210 x y w h
211 vert-rect
212 tex-rect)))
fedd9bca 213
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214(define (flip-pixels-vertically pixels width height)
215 "Create a new bytevector that reverses the rows in PIXELS, a WIDTH x
216HEIGHT, 32 bit color bytevector."
217 (let ((buffer (make-u8vector (bytevector-length pixels)))
218 (row-width (* width 4))) ; assuming 32 bit color
219 (let loop ((y 0))
220 (when (< y height)
221 (let* ((y* (- height y 1))
222 (source-start (* y row-width))
223 (target-start (* y* row-width)))
224 (bytevector-copy! pixels source-start buffer target-start row-width)
225 (loop (1+ y)))))
226 buffer))
227
228(define (surface->texture surface min-filter mag-filter wrap-s wrap-t)
229 "Convert SURFACE, an SDL2 surface object, into a texture that uses
230the given MIN-FILTER and MAG-FILTER."
231 ;; Convert to 32 bit RGBA color.
232 (call-with-surface (convert-surface-format surface 'abgr8888)
233 (lambda (surface)
234 (let* ((width (surface-width surface))
235 (height (surface-height surface))
236 ;; OpenGL textures use the bottom-left corner as the
237 ;; origin, whereas SDL uses the top-left, so the rows
238 ;; of pixels must be reversed before creating a
239 ;; texture from them.
240 (pixels (flip-pixels-vertically (surface-pixels surface)
241 width height)))
242 (make-texture pixels width height
243 #:min-filter min-filter
244 #:mag-filter mag-filter
245 #:wrap-s wrap-s
246 #:wrap-t wrap-t)))))
247
7015cd49 248(define* (load-image file #:key
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249 (min-filter 'nearest)
250 (mag-filter 'nearest)
251 (wrap-s 'repeat)
252 (wrap-t 'repeat))
253 "Load a texture from an image in FILE. MIN-FILTER and MAG-FILTER
254describe the method that should be used for minification and
255magnification. Valid values are 'nearest and 'linear. By default,
256'nearest is used."
5a07e08c 257 (call-with-surface ((@ (sdl2 image) load-image) file)
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258 (lambda (surface)
259 (surface->texture surface min-filter mag-filter wrap-s wrap-t))))
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260
261\f
262;;;
263;;; Texture Atlas
264;;;
265
266(define-record-type <texture-atlas>
267 (%make-texture-atlas texture vector)
268 texture-atlas?
269 (texture texture-atlas-texture)
270 (vector texture-atlas-vector))
271
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272(define (display-texture-atlas atlas port)
273 (format port
274 "#<texture-atlas texture: ~a size: ~d>"
275 (texture-atlas-texture atlas)
276 (vector-length (texture-atlas-vector atlas))))
277
278(set-record-type-printer! <texture-atlas> display-texture-atlas)
279
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280(define (list->texture-atlas texture rects)
281 "Return a new atlas for TEXTURE containing RECTS, a list of texture
282coordinate rects denoting the various tiles within."
283 (let ((v (make-vector (length rects))))
284 (let loop ((i 0)
285 (rects rects))
286 (match rects
287 (() (%make-texture-atlas texture v))
31b6f11b 288 (((x y width height) . rest)
fedd9bca 289 (vector-set! v i (make-texture-region texture (make-rect x y width height)))
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290 (loop (1+ i) rest))))))
291
292(define (texture-atlas texture . rects)
293 "Return a new atlas for TEXTURE containing RECTS, a series of
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2944-tuples in the form (x y width height) describing the various tiles
295within."
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296 (list->texture-atlas texture rects))
297
298(define (texture-atlas-ref atlas index)
31b6f11b 299 "Return the texture region associated with INDEX in
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300ATLAS."
301 (vector-ref (texture-atlas-vector atlas) index))
302
303(define* (split-texture texture tile-width tile-height #:key
304 (margin 0) (spacing 0))
305 "Return a new texture atlas that splits TEXTURE into a grid of
306TILE-WIDTH by TILE-HEIGHT rectangles. Optionally, each tile may have
307SPACING pixels of horizontal and vertical space between surrounding
308tiles and the entire image may have MARGIN pixels of empty space
309around its border.
310
311This type of texture atlas layout is very common for tile map
312terrain."
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313 (let* ((w (texture-width texture))
314 (h (texture-height texture))
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315 (sw (/ tile-width w))
316 (th (/ tile-height h))
317 (rows (/ (- h margin) (+ tile-height spacing)))
318 (columns (/ (- w margin) (+ tile-width spacing)))
319 (v (make-vector (* rows columns))))
320 (define (make-tile tx ty)
321 (let* ((x (+ (* tx (+ tile-width spacing)) margin))
322 (y (+ (* ty (+ tile-height spacing)) margin)))
fedd9bca 323 (make-texture-region texture (make-rect x y tile-width tile-height))))
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324 (let y-loop ((y 0))
325 (when (< y rows)
326 (let x-loop ((x 0))
327 (when (< x columns)
328 (vector-set! v (+ x (* y columns)) (make-tile x y))
329 (x-loop (1+ x))))
330 (y-loop (1+ y))))
331 (%make-texture-atlas texture v)))