| /* |
| Simple DirectMedia Layer |
| Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.org> |
| |
| This software is provided 'as-is', without any express or implied |
| warranty. In no event will the authors be held liable for any damages |
| arising from the use of this software. |
| |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it |
| freely, subject to the following restrictions: |
| |
| 1. The origin of this software must not be misrepresented; you must not |
| claim that you wrote the original software. If you use this software |
| in a product, an acknowledgment in the product documentation would be |
| appreciated but is not required. |
| 2. Altered source versions must be plainly marked as such, and must not be |
| misrepresented as being the original software. |
| 3. This notice may not be removed or altered from any source distribution. |
| */ |
| |
| /** |
| * \file SDL_blendmode.h |
| * |
| * Header file declaring the SDL_BlendMode enumeration |
| */ |
| |
| #ifndef SDL_blendmode_h_ |
| #define SDL_blendmode_h_ |
| |
| #include "begin_code.h" |
| /* Set up for C function definitions, even when using C++ */ |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /** |
| * \brief The blend mode used in SDL_RenderCopy() and drawing operations. |
| */ |
| typedef enum |
| { |
| SDL_BLENDMODE_NONE = 0x00000000, /**< no blending |
| dstRGBA = srcRGBA */ |
| SDL_BLENDMODE_BLEND = 0x00000001, /**< alpha blending |
| dstRGB = (srcRGB * srcA) + (dstRGB * (1-srcA)) |
| dstA = srcA + (dstA * (1-srcA)) */ |
| SDL_BLENDMODE_ADD = 0x00000002, /**< additive blending |
| dstRGB = (srcRGB * srcA) + dstRGB |
| dstA = dstA */ |
| SDL_BLENDMODE_MOD = 0x00000004, /**< color modulate |
| dstRGB = srcRGB * dstRGB |
| dstA = dstA */ |
| SDL_BLENDMODE_MUL = 0x00000008, /**< color multiply |
| dstRGB = (srcRGB * dstRGB) + (dstRGB * (1-srcA)) |
| dstA = (srcA * dstA) + (dstA * (1-srcA)) */ |
| SDL_BLENDMODE_INVALID = 0x7FFFFFFF |
| |
| /* Additional custom blend modes can be returned by SDL_ComposeCustomBlendMode() */ |
| |
| } SDL_BlendMode; |
| |
| /** |
| * \brief The blend operation used when combining source and destination pixel components |
| */ |
| typedef enum |
| { |
| SDL_BLENDOPERATION_ADD = 0x1, /**< dst + src: supported by all renderers */ |
| SDL_BLENDOPERATION_SUBTRACT = 0x2, /**< dst - src : supported by D3D9, D3D11, OpenGL, OpenGLES */ |
| SDL_BLENDOPERATION_REV_SUBTRACT = 0x3, /**< src - dst : supported by D3D9, D3D11, OpenGL, OpenGLES */ |
| SDL_BLENDOPERATION_MINIMUM = 0x4, /**< min(dst, src) : supported by D3D11 */ |
| SDL_BLENDOPERATION_MAXIMUM = 0x5 /**< max(dst, src) : supported by D3D11 */ |
| |
| } SDL_BlendOperation; |
| |
| /** |
| * \brief The normalized factor used to multiply pixel components |
| */ |
| typedef enum |
| { |
| SDL_BLENDFACTOR_ZERO = 0x1, /**< 0, 0, 0, 0 */ |
| SDL_BLENDFACTOR_ONE = 0x2, /**< 1, 1, 1, 1 */ |
| SDL_BLENDFACTOR_SRC_COLOR = 0x3, /**< srcR, srcG, srcB, srcA */ |
| SDL_BLENDFACTOR_ONE_MINUS_SRC_COLOR = 0x4, /**< 1-srcR, 1-srcG, 1-srcB, 1-srcA */ |
| SDL_BLENDFACTOR_SRC_ALPHA = 0x5, /**< srcA, srcA, srcA, srcA */ |
| SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA = 0x6, /**< 1-srcA, 1-srcA, 1-srcA, 1-srcA */ |
| SDL_BLENDFACTOR_DST_COLOR = 0x7, /**< dstR, dstG, dstB, dstA */ |
| SDL_BLENDFACTOR_ONE_MINUS_DST_COLOR = 0x8, /**< 1-dstR, 1-dstG, 1-dstB, 1-dstA */ |
| SDL_BLENDFACTOR_DST_ALPHA = 0x9, /**< dstA, dstA, dstA, dstA */ |
| SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA = 0xA /**< 1-dstA, 1-dstA, 1-dstA, 1-dstA */ |
| |
| } SDL_BlendFactor; |
| |
| /** |
| * Compose a custom blend mode for renderers. |
| * |
| * The functions SDL_SetRenderDrawBlendMode and SDL_SetTextureBlendMode accept |
| * the SDL_BlendMode returned by this function if the renderer supports it. |
| * |
| * A blend mode controls how the pixels from a drawing operation (source) get |
| * combined with the pixels from the render target (destination). First, the |
| * components of the source and destination pixels get multiplied with their |
| * blend factors. Then, the blend operation takes the two products and |
| * calculates the result that will get stored in the render target. |
| * |
| * Expressed in pseudocode, it would look like this: |
| * |
| * ```c |
| * dstRGB = colorOperation(srcRGB * srcColorFactor, dstRGB * dstColorFactor); |
| * dstA = alphaOperation(srcA * srcAlphaFactor, dstA * dstAlphaFactor); |
| * ``` |
| * |
| * Where the functions `colorOperation(src, dst)` and `alphaOperation(src, |
| * dst)` can return one of the following: |
| * |
| * - `src + dst` |
| * - `src - dst` |
| * - `dst - src` |
| * - `min(src, dst)` |
| * - `max(src, dst)` |
| * |
| * The red, green, and blue components are always multiplied with the first, |
| * second, and third components of the SDL_BlendFactor, respectively. The |
| * fourth component is not used. |
| * |
| * The alpha component is always multiplied with the fourth component of the |
| * SDL_BlendFactor. The other components are not used in the alpha |
| * calculation. |
| * |
| * Support for these blend modes varies for each renderer. To check if a |
| * specific SDL_BlendMode is supported, create a renderer and pass it to |
| * either SDL_SetRenderDrawBlendMode or SDL_SetTextureBlendMode. They will |
| * return with an error if the blend mode is not supported. |
| * |
| * This list describes the support of custom blend modes for each renderer in |
| * SDL 2.0.6. All renderers support the four blend modes listed in the |
| * SDL_BlendMode enumeration. |
| * |
| * - **direct3d**: Supports `SDL_BLENDOPERATION_ADD` with all factors. |
| * - **direct3d11**: Supports all operations with all factors. However, some |
| * factors produce unexpected results with `SDL_BLENDOPERATION_MINIMUM` and |
| * `SDL_BLENDOPERATION_MAXIMUM`. |
| * - **opengl**: Supports the `SDL_BLENDOPERATION_ADD` operation with all |
| * factors. OpenGL versions 1.1, 1.2, and 1.3 do not work correctly with SDL |
| * 2.0.6. |
| * - **opengles**: Supports the `SDL_BLENDOPERATION_ADD` operation with all |
| * factors. Color and alpha factors need to be the same. OpenGL ES 1 |
| * implementation specific: May also support `SDL_BLENDOPERATION_SUBTRACT` |
| * and `SDL_BLENDOPERATION_REV_SUBTRACT`. May support color and alpha |
| * operations being different from each other. May support color and alpha |
| * factors being different from each other. |
| * - **opengles2**: Supports the `SDL_BLENDOPERATION_ADD`, |
| * `SDL_BLENDOPERATION_SUBTRACT`, `SDL_BLENDOPERATION_REV_SUBTRACT` |
| * operations with all factors. |
| * - **psp**: No custom blend mode support. |
| * - **software**: No custom blend mode support. |
| * |
| * Some renderers do not provide an alpha component for the default render |
| * target. The `SDL_BLENDFACTOR_DST_ALPHA` and |
| * `SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA` factors do not have an effect in this |
| * case. |
| * |
| * \param srcColorFactor the SDL_BlendFactor applied to the red, green, and |
| * blue components of the source pixels |
| * \param dstColorFactor the SDL_BlendFactor applied to the red, green, and |
| * blue components of the destination pixels |
| * \param colorOperation the SDL_BlendOperation used to combine the red, |
| * green, and blue components of the source and |
| * destination pixels |
| * \param srcAlphaFactor the SDL_BlendFactor applied to the alpha component of |
| * the source pixels |
| * \param dstAlphaFactor the SDL_BlendFactor applied to the alpha component of |
| * the destination pixels |
| * \param alphaOperation the SDL_BlendOperation used to combine the alpha |
| * component of the source and destination pixels |
| * \returns an SDL_BlendMode that represents the chosen factors and |
| * operations. |
| * |
| * \since This function is available since SDL 2.0.6. |
| * |
| * \sa SDL_SetRenderDrawBlendMode |
| * \sa SDL_GetRenderDrawBlendMode |
| * \sa SDL_SetTextureBlendMode |
| * \sa SDL_GetTextureBlendMode |
| */ |
| extern DECLSPEC SDL_BlendMode SDLCALL SDL_ComposeCustomBlendMode(SDL_BlendFactor srcColorFactor, |
| SDL_BlendFactor dstColorFactor, |
| SDL_BlendOperation colorOperation, |
| SDL_BlendFactor srcAlphaFactor, |
| SDL_BlendFactor dstAlphaFactor, |
| SDL_BlendOperation alphaOperation); |
| |
| /* Ends C function definitions when using C++ */ |
| #ifdef __cplusplus |
| } |
| #endif |
| #include "close_code.h" |
| |
| #endif /* SDL_blendmode_h_ */ |
| |
| /* vi: set ts=4 sw=4 expandtab: */ |
