1 /*
2 * art_render.h: Modular rendering architecture.
3 *
4 * Libart_LGPL - library of basic graphic primitives
5 * Copyright (C) 2000 Raph Levien
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
16 *
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
21 */
23 #ifndef __ART_RENDER_H__
24 #define __ART_RENDER_H__
26 #ifdef __cplusplus
27 extern "C" {
28 #endif /* __cplusplus */
30 /* Render object */
32 #ifndef ART_MAX_DEPTH
33 #define ART_MAX_DEPTH 16
34 #endif
36 #if ART_MAX_DEPTH == 16
37 typedef art_u16 ArtPixMaxDepth;
38 #define ART_PIX_MAX_FROM_8(x) ((x) | ((x) << 8))
39 #define ART_PIX_8_FROM_MAX(x) (((x) + 0x80 - (((x) + 0x80) >> 8)) >> 8)
40 #else
41 #if ART_MAX_DEPTH == 8
42 typedef art_u8 ArtPixMaxDepth;
43 #define ART_PIX_MAX_FROM_8(x) (x)
44 #define ART_PIX_8_FROM_MAX(x) (x)
45 #else
46 #error ART_MAX_DEPTH must be either 8 or 16
47 #endif
48 #endif
50 #define ART_MAX_CHAN 16
52 typedef struct _ArtRender ArtRender;
53 typedef struct _ArtRenderCallback ArtRenderCallback;
54 typedef struct _ArtRenderMaskRun ArtRenderMaskRun;
55 typedef struct _ArtImageSource ArtImageSource;
56 typedef struct _ArtMaskSource ArtMaskSource;
58 typedef enum {
59 ART_ALPHA_NONE = 0,
60 ART_ALPHA_SEPARATE = 1,
61 ART_ALPHA_PREMUL = 2
62 } ArtAlphaType;
64 typedef enum {
65 ART_COMPOSITE_NORMAL,
66 ART_COMPOSITE_MULTIPLY,
67 /* todo: more */
68 ART_COMPOSITE_CUSTOM
69 } ArtCompositingMode;
71 typedef enum {
72 ART_IMAGE_SOURCE_CAN_CLEAR = 1,
73 ART_IMAGE_SOURCE_CAN_COMPOSITE = 2
74 } ArtImageSourceFlags;
76 struct _ArtRenderMaskRun {
77 int x;
78 int alpha;
79 };
81 struct _ArtRenderCallback {
82 void (*render) (ArtRenderCallback *self, ArtRender *render,
83 art_u8 *dest, int y);
84 void (*done) (ArtRenderCallback *self, ArtRender *render);
85 };
87 struct _ArtImageSource {
88 ArtRenderCallback super;
89 void (*negotiate) (ArtImageSource *self, ArtRender *render,
90 ArtImageSourceFlags *p_flags,
91 int *p_buf_depth, ArtAlphaType *p_alpha_type);
92 };
94 struct _ArtMaskSource {
95 ArtRenderCallback super;
96 int (*can_drive) (ArtMaskSource *self, ArtRender *render);
97 /* For each mask source, ::prepare() is invoked if it is not
98 a driver, or ::invoke_driver() if it is. */
99 void (*invoke_driver) (ArtMaskSource *self, ArtRender *render);
100 void (*prepare) (ArtMaskSource *self, ArtRender *render, art_boolean first);
101 };
103 struct _ArtRender {
104 /* parameters of destination image */
105 int x0, y0;
106 int x1, y1;
107 art_u8 *pixels;
108 int rowstride;
109 int n_chan;
110 int depth;
111 ArtAlphaType alpha_type;
113 art_boolean clear;
114 ArtPixMaxDepth clear_color[ART_MAX_CHAN + 1];
115 art_u32 opacity; /* [0..0x10000] */
117 ArtCompositingMode compositing_mode;
119 ArtAlphaGamma *alphagamma;
121 art_u8 *alpha_buf;
123 /* parameters of intermediate buffer */
124 int buf_depth;
125 ArtAlphaType buf_alpha;
126 art_u8 *image_buf;
128 /* driving alpha scanline data */
129 /* A "run" is a contiguous sequence of x values with the same alpha value. */
130 int n_run;
131 ArtRenderMaskRun *run;
133 /* A "span" is a contiguous sequence of x values with non-zero alpha. */
134 int n_span;
135 int *span_x;
137 art_boolean need_span;
138 };
140 ArtRender *
141 art_render_new (int x0, int y0, int x1, int y1,
142 art_u8 *pixels, int rowstride,
143 int n_chan, int depth, ArtAlphaType alpha_type,
144 ArtAlphaGamma *alphagamma);
146 void
147 art_render_invoke (ArtRender *render);
149 void
150 art_render_clear (ArtRender *render, const ArtPixMaxDepth *clear_color);
152 void
153 art_render_clear_rgb (ArtRender *render, art_u32 clear_rgb);
155 void
156 art_render_mask_solid (ArtRender *render, int opacity);
158 void
159 art_render_image_solid (ArtRender *render, ArtPixMaxDepth *color);
161 /* The next two functions are for custom mask sources only. */
162 void
163 art_render_add_mask_source (ArtRender *render, ArtMaskSource *mask_source);
165 void
166 art_render_invoke_callbacks (ArtRender *render, art_u8 *dest, int y);
168 /* The following function is for custom image sources only. */
169 void
170 art_render_add_image_source (ArtRender *render, ArtImageSource *image_source);
172 #ifdef __cplusplus
173 }
174 #endif /* __cplusplus */
176 #endif /* __ART_RENDER_H__ */