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| Rev | Author | Line No. | Line |
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| 1 | pmbaty | 1 | /* |
| 2 | Simple DirectMedia Layer |
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| 3 | Copyright (C) 1997-2023 Sam Lantinga <slouken@libsdl.org> |
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| 4 | |||
| 5 | This software is provided 'as-is', without any express or implied |
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| 6 | warranty. In no event will the authors be held liable for any damages |
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| 7 | arising from the use of this software. |
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| 8 | |||
| 9 | Permission is granted to anyone to use this software for any purpose, |
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| 10 | including commercial applications, and to alter it and redistribute it |
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| 11 | freely, subject to the following restrictions: |
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| 12 | |||
| 13 | 1. The origin of this software must not be misrepresented; you must not |
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| 14 | claim that you wrote the original software. If you use this software |
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| 15 | in a product, an acknowledgment in the product documentation would be |
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| 16 | appreciated but is not required. |
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| 17 | 2. Altered source versions must be plainly marked as such, and must not be |
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| 18 | misrepresented as being the original software. |
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| 19 | 3. This notice may not be removed or altered from any source distribution. |
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| 20 | */ |
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| 21 | |||
| 22 | /** |
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| 23 | * \file SDL_blendmode.h |
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| 24 | * |
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| 25 | * Header file declaring the SDL_BlendMode enumeration |
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| 26 | */ |
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| 27 | |||
| 28 | #ifndef SDL_blendmode_h_ |
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| 29 | #define SDL_blendmode_h_ |
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| 30 | |||
| 31 | #include "begin_code.h" |
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| 32 | /* Set up for C function definitions, even when using C++ */ |
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| 33 | #ifdef __cplusplus |
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| 34 | extern "C" { |
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| 35 | #endif |
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| 36 | |||
| 37 | /** |
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| 38 | * \brief The blend mode used in SDL_RenderCopy() and drawing operations. |
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| 39 | */ |
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| 40 | typedef enum |
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| 41 | { |
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| 42 | SDL_BLENDMODE_NONE = 0x00000000, /**< no blending |
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| 43 | dstRGBA = srcRGBA */ |
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| 44 | SDL_BLENDMODE_BLEND = 0x00000001, /**< alpha blending |
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| 45 | dstRGB = (srcRGB * srcA) + (dstRGB * (1-srcA)) |
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| 46 | dstA = srcA + (dstA * (1-srcA)) */ |
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| 47 | SDL_BLENDMODE_ADD = 0x00000002, /**< additive blending |
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| 48 | dstRGB = (srcRGB * srcA) + dstRGB |
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| 49 | dstA = dstA */ |
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| 50 | SDL_BLENDMODE_MOD = 0x00000004, /**< color modulate |
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| 51 | dstRGB = srcRGB * dstRGB |
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| 52 | dstA = dstA */ |
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| 53 | SDL_BLENDMODE_MUL = 0x00000008, /**< color multiply |
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| 54 | dstRGB = (srcRGB * dstRGB) + (dstRGB * (1-srcA)) |
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| 55 | dstA = dstA */ |
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| 56 | SDL_BLENDMODE_INVALID = 0x7FFFFFFF |
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| 57 | |||
| 58 | /* Additional custom blend modes can be returned by SDL_ComposeCustomBlendMode() */ |
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| 59 | |||
| 60 | } SDL_BlendMode; |
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| 61 | |||
| 62 | /** |
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| 63 | * \brief The blend operation used when combining source and destination pixel components |
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| 64 | */ |
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| 65 | typedef enum |
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| 66 | { |
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| 67 | SDL_BLENDOPERATION_ADD = 0x1, /**< dst + src: supported by all renderers */ |
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| 68 | SDL_BLENDOPERATION_SUBTRACT = 0x2, /**< dst - src : supported by D3D9, D3D11, OpenGL, OpenGLES */ |
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| 69 | SDL_BLENDOPERATION_REV_SUBTRACT = 0x3, /**< src - dst : supported by D3D9, D3D11, OpenGL, OpenGLES */ |
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| 70 | SDL_BLENDOPERATION_MINIMUM = 0x4, /**< min(dst, src) : supported by D3D9, D3D11 */ |
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| 71 | SDL_BLENDOPERATION_MAXIMUM = 0x5 /**< max(dst, src) : supported by D3D9, D3D11 */ |
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| 72 | } SDL_BlendOperation; |
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| 73 | |||
| 74 | /** |
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| 75 | * \brief The normalized factor used to multiply pixel components |
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| 76 | */ |
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| 77 | typedef enum |
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| 78 | { |
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| 79 | SDL_BLENDFACTOR_ZERO = 0x1, /**< 0, 0, 0, 0 */ |
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| 80 | SDL_BLENDFACTOR_ONE = 0x2, /**< 1, 1, 1, 1 */ |
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| 81 | SDL_BLENDFACTOR_SRC_COLOR = 0x3, /**< srcR, srcG, srcB, srcA */ |
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| 82 | SDL_BLENDFACTOR_ONE_MINUS_SRC_COLOR = 0x4, /**< 1-srcR, 1-srcG, 1-srcB, 1-srcA */ |
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| 83 | SDL_BLENDFACTOR_SRC_ALPHA = 0x5, /**< srcA, srcA, srcA, srcA */ |
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| 84 | SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA = 0x6, /**< 1-srcA, 1-srcA, 1-srcA, 1-srcA */ |
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| 85 | SDL_BLENDFACTOR_DST_COLOR = 0x7, /**< dstR, dstG, dstB, dstA */ |
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| 86 | SDL_BLENDFACTOR_ONE_MINUS_DST_COLOR = 0x8, /**< 1-dstR, 1-dstG, 1-dstB, 1-dstA */ |
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| 87 | SDL_BLENDFACTOR_DST_ALPHA = 0x9, /**< dstA, dstA, dstA, dstA */ |
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| 88 | SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA = 0xA /**< 1-dstA, 1-dstA, 1-dstA, 1-dstA */ |
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| 89 | } SDL_BlendFactor; |
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| 90 | |||
| 91 | /** |
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| 92 | * Compose a custom blend mode for renderers. |
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| 93 | * |
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| 94 | * The functions SDL_SetRenderDrawBlendMode and SDL_SetTextureBlendMode accept |
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| 95 | * the SDL_BlendMode returned by this function if the renderer supports it. |
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| 96 | * |
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| 97 | * A blend mode controls how the pixels from a drawing operation (source) get |
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| 98 | * combined with the pixels from the render target (destination). First, the |
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| 99 | * components of the source and destination pixels get multiplied with their |
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| 100 | * blend factors. Then, the blend operation takes the two products and |
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| 101 | * calculates the result that will get stored in the render target. |
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| 102 | * |
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| 103 | * Expressed in pseudocode, it would look like this: |
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| 104 | * |
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| 105 | * ```c |
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| 106 | * dstRGB = colorOperation(srcRGB * srcColorFactor, dstRGB * dstColorFactor); |
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| 107 | * dstA = alphaOperation(srcA * srcAlphaFactor, dstA * dstAlphaFactor); |
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| 108 | * ``` |
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| 109 | * |
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| 110 | * Where the functions `colorOperation(src, dst)` and `alphaOperation(src, |
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| 111 | * dst)` can return one of the following: |
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| 112 | * |
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| 113 | * - `src + dst` |
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| 114 | * - `src - dst` |
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| 115 | * - `dst - src` |
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| 116 | * - `min(src, dst)` |
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| 117 | * - `max(src, dst)` |
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| 118 | * |
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| 119 | * The red, green, and blue components are always multiplied with the first, |
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| 120 | * second, and third components of the SDL_BlendFactor, respectively. The |
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| 121 | * fourth component is not used. |
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| 122 | * |
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| 123 | * The alpha component is always multiplied with the fourth component of the |
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| 124 | * SDL_BlendFactor. The other components are not used in the alpha |
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| 125 | * calculation. |
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| 126 | * |
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| 127 | * Support for these blend modes varies for each renderer. To check if a |
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| 128 | * specific SDL_BlendMode is supported, create a renderer and pass it to |
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| 129 | * either SDL_SetRenderDrawBlendMode or SDL_SetTextureBlendMode. They will |
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| 130 | * return with an error if the blend mode is not supported. |
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| 131 | * |
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| 132 | * This list describes the support of custom blend modes for each renderer in |
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| 133 | * SDL 2.0.6. All renderers support the four blend modes listed in the |
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| 134 | * SDL_BlendMode enumeration. |
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| 135 | * |
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| 136 | * - **direct3d**: Supports all operations with all factors. However, some |
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| 137 | * factors produce unexpected results with `SDL_BLENDOPERATION_MINIMUM` and |
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| 138 | * `SDL_BLENDOPERATION_MAXIMUM`. |
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| 139 | * - **direct3d11**: Same as Direct3D 9. |
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| 140 | * - **opengl**: Supports the `SDL_BLENDOPERATION_ADD` operation with all |
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| 141 | * factors. OpenGL versions 1.1, 1.2, and 1.3 do not work correctly with SDL |
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| 142 | * 2.0.6. |
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| 143 | * - **opengles**: Supports the `SDL_BLENDOPERATION_ADD` operation with all |
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| 144 | * factors. Color and alpha factors need to be the same. OpenGL ES 1 |
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| 145 | * implementation specific: May also support `SDL_BLENDOPERATION_SUBTRACT` |
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| 146 | * and `SDL_BLENDOPERATION_REV_SUBTRACT`. May support color and alpha |
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| 147 | * operations being different from each other. May support color and alpha |
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| 148 | * factors being different from each other. |
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| 149 | * - **opengles2**: Supports the `SDL_BLENDOPERATION_ADD`, |
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| 150 | * `SDL_BLENDOPERATION_SUBTRACT`, `SDL_BLENDOPERATION_REV_SUBTRACT` |
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| 151 | * operations with all factors. |
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| 152 | * - **psp**: No custom blend mode support. |
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| 153 | * - **software**: No custom blend mode support. |
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| 154 | * |
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| 155 | * Some renderers do not provide an alpha component for the default render |
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| 156 | * target. The `SDL_BLENDFACTOR_DST_ALPHA` and |
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| 157 | * `SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA` factors do not have an effect in this |
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| 158 | * case. |
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| 159 | * |
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| 160 | * \param srcColorFactor the SDL_BlendFactor applied to the red, green, and |
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| 161 | * blue components of the source pixels |
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| 162 | * \param dstColorFactor the SDL_BlendFactor applied to the red, green, and |
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| 163 | * blue components of the destination pixels |
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| 164 | * \param colorOperation the SDL_BlendOperation used to combine the red, |
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| 165 | * green, and blue components of the source and |
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| 166 | * destination pixels |
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| 167 | * \param srcAlphaFactor the SDL_BlendFactor applied to the alpha component of |
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| 168 | * the source pixels |
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| 169 | * \param dstAlphaFactor the SDL_BlendFactor applied to the alpha component of |
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| 170 | * the destination pixels |
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| 171 | * \param alphaOperation the SDL_BlendOperation used to combine the alpha |
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| 172 | * component of the source and destination pixels |
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| 173 | * \returns an SDL_BlendMode that represents the chosen factors and |
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| 174 | * operations. |
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| 175 | * |
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| 176 | * \since This function is available since SDL 2.0.6. |
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| 177 | * |
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| 178 | * \sa SDL_SetRenderDrawBlendMode |
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| 179 | * \sa SDL_GetRenderDrawBlendMode |
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| 180 | * \sa SDL_SetTextureBlendMode |
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| 181 | * \sa SDL_GetTextureBlendMode |
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| 182 | */ |
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| 183 | extern DECLSPEC SDL_BlendMode SDLCALL SDL_ComposeCustomBlendMode(SDL_BlendFactor srcColorFactor, |
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| 184 | SDL_BlendFactor dstColorFactor, |
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| 185 | SDL_BlendOperation colorOperation, |
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| 186 | SDL_BlendFactor srcAlphaFactor, |
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| 187 | SDL_BlendFactor dstAlphaFactor, |
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| 188 | SDL_BlendOperation alphaOperation); |
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| 189 | |||
| 190 | /* Ends C function definitions when using C++ */ |
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| 191 | #ifdef __cplusplus |
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| 192 | } |
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| 193 | #endif |
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| 194 | #include "close_code.h" |
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| 195 | |||
| 196 | #endif /* SDL_blendmode_h_ */ |
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| 197 | |||
| 198 | /* vi: set ts=4 sw=4 expandtab: */ |