SDL 3.0
SDL_blendmode.h
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1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2024 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 * \file SDL_blendmode.h
24 *
25 * Header file declaring the SDL_BlendMode enumeration
26 */
27
28#ifndef SDL_blendmode_h_
29#define SDL_blendmode_h_
30
31#include <SDL3/SDL_begin_code.h>
32/* Set up for C function definitions, even when using C++ */
33#ifdef __cplusplus
34extern "C" {
35#endif
36
37/**
38 * An enumeration of blend modes used in drawing operations.
39 *
40 * Note that additional values may be obtained from
41 * SDL_ComposeCustomBlendMode.
42 *
43 * \since This enum is available since SDL 3.0.0.
44 *
45 * \sa SDL_ComposeCustomBlendMode
46 */
47typedef enum SDL_BlendMode
48{
49 SDL_BLENDMODE_NONE = 0x00000000, /**< no blending
50 dstRGBA = srcRGBA */
51 SDL_BLENDMODE_BLEND = 0x00000001, /**< alpha blending
52 dstRGB = (srcRGB * srcA) + (dstRGB * (1-srcA))
53 dstA = srcA + (dstA * (1-srcA)) */
54 SDL_BLENDMODE_ADD = 0x00000002, /**< additive blending
55 dstRGB = (srcRGB * srcA) + dstRGB
56 dstA = dstA */
57 SDL_BLENDMODE_MOD = 0x00000004, /**< color modulate
58 dstRGB = srcRGB * dstRGB
59 dstA = dstA */
60 SDL_BLENDMODE_MUL = 0x00000008, /**< color multiply
61 dstRGB = (srcRGB * dstRGB) + (dstRGB * (1-srcA))
62 dstA = dstA */
63 SDL_BLENDMODE_INVALID = 0x7FFFFFFF
64
65 /* Additional custom blend modes can be returned by SDL_ComposeCustomBlendMode() */
66
68
69/**
70 * The blend operation used when combining source and destination pixel
71 * components.
72 *
73 * \since This enum is available since SDL 3.0.0.
74 */
76{
77 SDL_BLENDOPERATION_ADD = 0x1, /**< dst + src: supported by all renderers */
78 SDL_BLENDOPERATION_SUBTRACT = 0x2, /**< src - dst : supported by D3D9, D3D11, OpenGL, OpenGLES */
79 SDL_BLENDOPERATION_REV_SUBTRACT = 0x3, /**< dst - src : supported by D3D9, D3D11, OpenGL, OpenGLES */
80 SDL_BLENDOPERATION_MINIMUM = 0x4, /**< min(dst, src) : supported by D3D9, D3D11 */
81 SDL_BLENDOPERATION_MAXIMUM = 0x5 /**< max(dst, src) : supported by D3D9, D3D11 */
83
84/**
85 * The normalized factor used to multiply pixel components.
86 *
87 * The blend factors are multiplied with the pixels from a drawing operation
88 * (src) and the pixels from the render target (dst) before the blend
89 * operation. The comma-separated factors listed above are always applied in
90 * the component order red, green, blue, and alpha.
91 *
92 * \since This enum is available since SDL 3.0.0.
93 */
94typedef enum SDL_BlendFactor
95{
96 SDL_BLENDFACTOR_ZERO = 0x1, /**< 0, 0, 0, 0 */
97 SDL_BLENDFACTOR_ONE = 0x2, /**< 1, 1, 1, 1 */
98 SDL_BLENDFACTOR_SRC_COLOR = 0x3, /**< srcR, srcG, srcB, srcA */
99 SDL_BLENDFACTOR_ONE_MINUS_SRC_COLOR = 0x4, /**< 1-srcR, 1-srcG, 1-srcB, 1-srcA */
100 SDL_BLENDFACTOR_SRC_ALPHA = 0x5, /**< srcA, srcA, srcA, srcA */
101 SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA = 0x6, /**< 1-srcA, 1-srcA, 1-srcA, 1-srcA */
102 SDL_BLENDFACTOR_DST_COLOR = 0x7, /**< dstR, dstG, dstB, dstA */
103 SDL_BLENDFACTOR_ONE_MINUS_DST_COLOR = 0x8, /**< 1-dstR, 1-dstG, 1-dstB, 1-dstA */
104 SDL_BLENDFACTOR_DST_ALPHA = 0x9, /**< dstA, dstA, dstA, dstA */
105 SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA = 0xA /**< 1-dstA, 1-dstA, 1-dstA, 1-dstA */
107
108/**
109 * Compose a custom blend mode for renderers.
110 *
111 * The functions SDL_SetRenderDrawBlendMode and SDL_SetTextureBlendMode accept
112 * the SDL_BlendMode returned by this function if the renderer supports it.
113 *
114 * A blend mode controls how the pixels from a drawing operation (source) get
115 * combined with the pixels from the render target (destination). First, the
116 * components of the source and destination pixels get multiplied with their
117 * blend factors. Then, the blend operation takes the two products and
118 * calculates the result that will get stored in the render target.
119 *
120 * Expressed in pseudocode, it would look like this:
121 *
122 * ```c
123 * dstRGB = colorOperation(srcRGB * srcColorFactor, dstRGB * dstColorFactor);
124 * dstA = alphaOperation(srcA * srcAlphaFactor, dstA * dstAlphaFactor);
125 * ```
126 *
127 * Where the functions `colorOperation(src, dst)` and `alphaOperation(src,
128 * dst)` can return one of the following:
129 *
130 * - `src + dst`
131 * - `src - dst`
132 * - `dst - src`
133 * - `min(src, dst)`
134 * - `max(src, dst)`
135 *
136 * The red, green, and blue components are always multiplied with the first,
137 * second, and third components of the SDL_BlendFactor, respectively. The
138 * fourth component is not used.
139 *
140 * The alpha component is always multiplied with the fourth component of the
141 * SDL_BlendFactor. The other components are not used in the alpha
142 * calculation.
143 *
144 * Support for these blend modes varies for each renderer. To check if a
145 * specific SDL_BlendMode is supported, create a renderer and pass it to
146 * either SDL_SetRenderDrawBlendMode or SDL_SetTextureBlendMode. They will
147 * return with an error if the blend mode is not supported.
148 *
149 * This list describes the support of custom blend modes for each renderer.
150 * All renderers support the four blend modes listed in the SDL_BlendMode
151 * enumeration.
152 *
153 * - **direct3d**: Supports all operations with all factors. However, some
154 * factors produce unexpected results with `SDL_BLENDOPERATION_MINIMUM` and
155 * `SDL_BLENDOPERATION_MAXIMUM`.
156 * - **direct3d11**: Same as Direct3D 9.
157 * - **opengl**: Supports the `SDL_BLENDOPERATION_ADD` operation with all
158 * factors. OpenGL versions 1.1, 1.2, and 1.3 do not work correctly here.
159 * - **opengles2**: Supports the `SDL_BLENDOPERATION_ADD`,
160 * `SDL_BLENDOPERATION_SUBTRACT`, `SDL_BLENDOPERATION_REV_SUBTRACT`
161 * operations with all factors.
162 * - **psp**: No custom blend mode support.
163 * - **software**: No custom blend mode support.
164 *
165 * Some renderers do not provide an alpha component for the default render
166 * target. The `SDL_BLENDFACTOR_DST_ALPHA` and
167 * `SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA` factors do not have an effect in this
168 * case.
169 *
170 * \param srcColorFactor the SDL_BlendFactor applied to the red, green, and
171 * blue components of the source pixels
172 * \param dstColorFactor the SDL_BlendFactor applied to the red, green, and
173 * blue components of the destination pixels
174 * \param colorOperation the SDL_BlendOperation used to combine the red,
175 * green, and blue components of the source and
176 * destination pixels
177 * \param srcAlphaFactor the SDL_BlendFactor applied to the alpha component of
178 * the source pixels
179 * \param dstAlphaFactor the SDL_BlendFactor applied to the alpha component of
180 * the destination pixels
181 * \param alphaOperation the SDL_BlendOperation used to combine the alpha
182 * component of the source and destination pixels
183 * \returns an SDL_BlendMode that represents the chosen factors and
184 * operations.
185 *
186 * \since This function is available since SDL 3.0.0.
187 *
188 * \sa SDL_SetRenderDrawBlendMode
189 * \sa SDL_GetRenderDrawBlendMode
190 * \sa SDL_SetTextureBlendMode
191 * \sa SDL_GetTextureBlendMode
192 */
193extern DECLSPEC SDL_BlendMode SDLCALL SDL_ComposeCustomBlendMode(SDL_BlendFactor srcColorFactor,
194 SDL_BlendFactor dstColorFactor,
195 SDL_BlendOperation colorOperation,
196 SDL_BlendFactor srcAlphaFactor,
197 SDL_BlendFactor dstAlphaFactor,
198 SDL_BlendOperation alphaOperation);
199
200/* Ends C function definitions when using C++ */
201#ifdef __cplusplus
202}
203#endif
204#include <SDL3/SDL_close_code.h>
205
206#endif /* SDL_blendmode_h_ */
SDL_BlendOperation
@ SDL_BLENDOPERATION_MAXIMUM
@ SDL_BLENDOPERATION_MINIMUM
@ SDL_BLENDOPERATION_REV_SUBTRACT
@ SDL_BLENDOPERATION_ADD
@ SDL_BLENDOPERATION_SUBTRACT
SDL_BlendMode
@ SDL_BLENDMODE_NONE
@ SDL_BLENDMODE_ADD
@ SDL_BLENDMODE_BLEND
@ SDL_BLENDMODE_INVALID
@ SDL_BLENDMODE_MUL
@ SDL_BLENDMODE_MOD
SDL_BlendMode SDL_ComposeCustomBlendMode(SDL_BlendFactor srcColorFactor, SDL_BlendFactor dstColorFactor, SDL_BlendOperation colorOperation, SDL_BlendFactor srcAlphaFactor, SDL_BlendFactor dstAlphaFactor, SDL_BlendOperation alphaOperation)
SDL_BlendFactor
@ SDL_BLENDFACTOR_ONE_MINUS_SRC_COLOR
@ SDL_BLENDFACTOR_ZERO
@ SDL_BLENDFACTOR_SRC_COLOR
@ SDL_BLENDFACTOR_SRC_ALPHA
@ SDL_BLENDFACTOR_ONE_MINUS_DST_COLOR
@ SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA
@ SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA
@ SDL_BLENDFACTOR_DST_ALPHA
@ SDL_BLENDFACTOR_DST_COLOR
@ SDL_BLENDFACTOR_ONE