Mercurial > foo_out_sdl

comparison SDL3/SDL_blendmode.h @ 1:20d02a178406 default tip

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
*: check in everything else yay
author Paper <paper@tflc.us>
date Mon, 05 Jan 2026 02:15:46 -0500
parents
children
comparison
equal deleted inserted replaced
0:e9bb126753e7 1:20d02a178406
1 /*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
4
5 This software is provided 'as-is', without any express or implied
6 warranty. In no event will the authors be held liable for any damages
7 arising from the use of this software.
8
9 Permission is granted to anyone to use this software for any purpose,
10 including commercial applications, and to alter it and redistribute it
11 freely, subject to the following restrictions:
12
13 1. The origin of this software must not be misrepresented; you must not
14 claim that you wrote the original software. If you use this software
15 in a product, an acknowledgment in the product documentation would be
16 appreciated but is not required.
17 2. Altered source versions must be plainly marked as such, and must not be
18 misrepresented as being the original software.
19 3. This notice may not be removed or altered from any source distribution.
20 */
21
22 /**
23 * # CategoryBlendmode
24 *
25 * Blend modes decide how two colors will mix together. There are both
26 * standard modes for basic needs and a means to create custom modes,
27 * dictating what sort of math to do on what color components.
28 */
29
30 #ifndef SDL_blendmode_h_
31 #define SDL_blendmode_h_
32
33 #include <SDL3/SDL_stdinc.h>
34
35 #include <SDL3/SDL_begin_code.h>
36 /* Set up for C function definitions, even when using C++ */
37 #ifdef __cplusplus
38 extern "C" {
39 #endif
40
41 /**
42 * A set of blend modes used in drawing operations.
43 *
44 * These predefined blend modes are supported everywhere.
45 *
46 * Additional values may be obtained from SDL_ComposeCustomBlendMode.
47 *
48 * \since This datatype is available since SDL 3.2.0.
49 *
50 * \sa SDL_ComposeCustomBlendMode
51 */
52 typedef Uint32 SDL_BlendMode;
53
54 #define SDL_BLENDMODE_NONE 0x00000000u /**< no blending: dstRGBA = srcRGBA */
55 #define SDL_BLENDMODE_BLEND 0x00000001u /**< alpha blending: dstRGB = (srcRGB * srcA) + (dstRGB * (1-srcA)), dstA = srcA + (dstA * (1-srcA)) */
56 #define SDL_BLENDMODE_BLEND_PREMULTIPLIED 0x00000010u /**< pre-multiplied alpha blending: dstRGBA = srcRGBA + (dstRGBA * (1-srcA)) */
57 #define SDL_BLENDMODE_ADD 0x00000002u /**< additive blending: dstRGB = (srcRGB * srcA) + dstRGB, dstA = dstA */
58 #define SDL_BLENDMODE_ADD_PREMULTIPLIED 0x00000020u /**< pre-multiplied additive blending: dstRGB = srcRGB + dstRGB, dstA = dstA */
59 #define SDL_BLENDMODE_MOD 0x00000004u /**< color modulate: dstRGB = srcRGB * dstRGB, dstA = dstA */
60 #define SDL_BLENDMODE_MUL 0x00000008u /**< color multiply: dstRGB = (srcRGB * dstRGB) + (dstRGB * (1-srcA)), dstA = dstA */
61 #define SDL_BLENDMODE_INVALID 0x7FFFFFFFu
62
63 /**
64 * The blend operation used when combining source and destination pixel
65 * components.
66 *
67 * \since This enum is available since SDL 3.2.0.
68 */
69 typedef enum SDL_BlendOperation
70 {
71 SDL_BLENDOPERATION_ADD = 0x1, /**< dst + src: supported by all renderers */
72 SDL_BLENDOPERATION_SUBTRACT = 0x2, /**< src - dst : supported by D3D, OpenGL, OpenGLES, and Vulkan */
73 SDL_BLENDOPERATION_REV_SUBTRACT = 0x3, /**< dst - src : supported by D3D, OpenGL, OpenGLES, and Vulkan */
74 SDL_BLENDOPERATION_MINIMUM = 0x4, /**< min(dst, src) : supported by D3D, OpenGL, OpenGLES, and Vulkan */
75 SDL_BLENDOPERATION_MAXIMUM = 0x5 /**< max(dst, src) : supported by D3D, OpenGL, OpenGLES, and Vulkan */
76 } SDL_BlendOperation;
77
78 /**
79 * The normalized factor used to multiply pixel components.
80 *
81 * The blend factors are multiplied with the pixels from a drawing operation
82 * (src) and the pixels from the render target (dst) before the blend
83 * operation. The comma-separated factors listed above are always applied in
84 * the component order red, green, blue, and alpha.
85 *
86 * \since This enum is available since SDL 3.2.0.
87 */
88 typedef enum SDL_BlendFactor
89 {
90 SDL_BLENDFACTOR_ZERO = 0x1, /**< 0, 0, 0, 0 */
91 SDL_BLENDFACTOR_ONE = 0x2, /**< 1, 1, 1, 1 */
92 SDL_BLENDFACTOR_SRC_COLOR = 0x3, /**< srcR, srcG, srcB, srcA */
93 SDL_BLENDFACTOR_ONE_MINUS_SRC_COLOR = 0x4, /**< 1-srcR, 1-srcG, 1-srcB, 1-srcA */
94 SDL_BLENDFACTOR_SRC_ALPHA = 0x5, /**< srcA, srcA, srcA, srcA */
95 SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA = 0x6, /**< 1-srcA, 1-srcA, 1-srcA, 1-srcA */
96 SDL_BLENDFACTOR_DST_COLOR = 0x7, /**< dstR, dstG, dstB, dstA */
97 SDL_BLENDFACTOR_ONE_MINUS_DST_COLOR = 0x8, /**< 1-dstR, 1-dstG, 1-dstB, 1-dstA */
98 SDL_BLENDFACTOR_DST_ALPHA = 0x9, /**< dstA, dstA, dstA, dstA */
99 SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA = 0xA /**< 1-dstA, 1-dstA, 1-dstA, 1-dstA */
100 } SDL_BlendFactor;
101
102 /**
103 * Compose a custom blend mode for renderers.
104 *
105 * The functions SDL_SetRenderDrawBlendMode and SDL_SetTextureBlendMode accept
106 * the SDL_BlendMode returned by this function if the renderer supports it.
107 *
108 * A blend mode controls how the pixels from a drawing operation (source) get
109 * combined with the pixels from the render target (destination). First, the
110 * components of the source and destination pixels get multiplied with their
111 * blend factors. Then, the blend operation takes the two products and
112 * calculates the result that will get stored in the render target.
113 *
114 * Expressed in pseudocode, it would look like this:
115 *
116 * ```c
117 * dstRGB = colorOperation(srcRGB * srcColorFactor, dstRGB * dstColorFactor);
118 * dstA = alphaOperation(srcA * srcAlphaFactor, dstA * dstAlphaFactor);
119 * ```
120 *
121 * Where the functions `colorOperation(src, dst)` and `alphaOperation(src,
122 * dst)` can return one of the following:
123 *
124 * - `src + dst`
125 * - `src - dst`
126 * - `dst - src`
127 * - `min(src, dst)`
128 * - `max(src, dst)`
129 *
130 * The red, green, and blue components are always multiplied with the first,
131 * second, and third components of the SDL_BlendFactor, respectively. The
132 * fourth component is not used.
133 *
134 * The alpha component is always multiplied with the fourth component of the
135 * SDL_BlendFactor. The other components are not used in the alpha
136 * calculation.
137 *
138 * Support for these blend modes varies for each renderer. To check if a
139 * specific SDL_BlendMode is supported, create a renderer and pass it to
140 * either SDL_SetRenderDrawBlendMode or SDL_SetTextureBlendMode. They will
141 * return with an error if the blend mode is not supported.
142 *
143 * This list describes the support of custom blend modes for each renderer.
144 * All renderers support the four blend modes listed in the SDL_BlendMode
145 * enumeration.
146 *
147 * - **direct3d**: Supports all operations with all factors. However, some
148 * factors produce unexpected results with `SDL_BLENDOPERATION_MINIMUM` and
149 * `SDL_BLENDOPERATION_MAXIMUM`.
150 * - **direct3d11**: Same as Direct3D 9.
151 * - **opengl**: Supports the `SDL_BLENDOPERATION_ADD` operation with all
152 * factors. OpenGL versions 1.1, 1.2, and 1.3 do not work correctly here.
153 * - **opengles2**: Supports the `SDL_BLENDOPERATION_ADD`,
154 * `SDL_BLENDOPERATION_SUBTRACT`, `SDL_BLENDOPERATION_REV_SUBTRACT`
155 * operations with all factors.
156 * - **psp**: No custom blend mode support.
157 * - **software**: No custom blend mode support.
158 *
159 * Some renderers do not provide an alpha component for the default render
160 * target. The `SDL_BLENDFACTOR_DST_ALPHA` and
161 * `SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA` factors do not have an effect in this
162 * case.
163 *
164 * \param srcColorFactor the SDL_BlendFactor applied to the red, green, and
165 * blue components of the source pixels.
166 * \param dstColorFactor the SDL_BlendFactor applied to the red, green, and
167 * blue components of the destination pixels.
168 * \param colorOperation the SDL_BlendOperation used to combine the red,
169 * green, and blue components of the source and
170 * destination pixels.
171 * \param srcAlphaFactor the SDL_BlendFactor applied to the alpha component of
172 * the source pixels.
173 * \param dstAlphaFactor the SDL_BlendFactor applied to the alpha component of
174 * the destination pixels.
175 * \param alphaOperation the SDL_BlendOperation used to combine the alpha
176 * component of the source and destination pixels.
177 * \returns an SDL_BlendMode that represents the chosen factors and
178 * operations.
179 *
180 * \threadsafety It is safe to call this function from any thread.
181 *
182 * \since This function is available since SDL 3.2.0.
183 *
184 * \sa SDL_SetRenderDrawBlendMode
185 * \sa SDL_GetRenderDrawBlendMode
186 * \sa SDL_SetTextureBlendMode
187 * \sa SDL_GetTextureBlendMode
188 */
189 extern SDL_DECLSPEC SDL_BlendMode SDLCALL SDL_ComposeCustomBlendMode(SDL_BlendFactor srcColorFactor,
190 SDL_BlendFactor dstColorFactor,
191 SDL_BlendOperation colorOperation,
192 SDL_BlendFactor srcAlphaFactor,
193 SDL_BlendFactor dstAlphaFactor,
194 SDL_BlendOperation alphaOperation);
195
196 /* Ends C function definitions when using C++ */
197 #ifdef __cplusplus
198 }
199 #endif
200 #include <SDL3/SDL_close_code.h>
201
202 #endif /* SDL_blendmode_h_ */