#pragma section-numbers off #pragma camelcase off || DRAFT|| = SDL_ComposeCustomBlendMode = Use this function to compose a custom blend mode for renderers. <> == Syntax == {{{#!highlight cpp SDL_BlendMode SDL_ComposeCustomBlendMode(SDL_BlendFactor srcColorFactor, SDL_BlendFactor dstColorFactor, SDL_BlendOperation colorOperation, SDL_BlendFactor srcAlphaFactor, SDL_BlendFactor dstAlphaFactor, SDL_BlendOperation alphaOperation) }}} == Function Parameters == ||'''srcColorFactor'''||the [[SDL_BlendFactor]] applied to the red, green, and blue components of the source pixels|| ||'''dstColorFactor'''||the [[SDL_BlendFactor]] applied to the red, green, and blue components of the destination pixels|| ||'''colorOperation'''||the [[SDL_BlendOperation]] used to combine the red, green, and blue components of the source and destination pixels|| ||'''srcAlphaFactor'''||the [[SDL_BlendFactor]] applied to the alpha component of the source pixels|| ||'''dstAlphaFactor'''||the [[SDL_BlendFactor]] applied to the alpha component of the destination pixels|| ||'''alphaOperation'''||the [[SDL_BlendOperation]] used to combine the alpha component of the source and destination pixels|| == Return Value == Returns an [[SDL_BlendMode]] that represents the chosen factors and operations. == Code Examples == {{{#!highlight cpp You can add your code example here }}} == Remarks == 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: {{{ 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. == Version == This function is available in SDL 2.0.6. == Related Functions == .[[SDL_SetRenderDrawBlendMode]] .[[SDL_GetRenderDrawBlendMode]] .[[SDL_SetTextureBlendMode]] .[[SDL_GetTextureBlendMode]] ---- [[CategoryAPI]], [[CategoryRender]]