Implemented more flexible blending modes for accelerated renderers

This fixes bug 2594 - Propose new blend mode, SDL_BLENDMODE_BLEND_DSTA

	blendMode = SDL_ComposeCustomBlendMode(SDL_BLENDFACTOR_SRC_ALPHA,
	                                       SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA,
	                                       SDL_BLENDOPERATION_ADD,
	                                       SDL_BLENDFACTOR_ZERO,
	                                       SDL_BLENDFACTOR_ONE,
	                                       SDL_BLENDOPERATION_ADD);

This fixes bug 2828 - Subtractive Blending

	blendMode = SDL_ComposeCustomBlendMode(SDL_BLENDFACTOR_SRC_ALPHA,
	                                       SDL_BLENDFACTOR_ONE,
	                                       SDL_BLENDOPERATION_SUBTRACT,
	                                       SDL_BLENDFACTOR_ZERO,
	                                       SDL_BLENDFACTOR_ONE,
	                                       SDL_BLENDOPERATION_SUBTRACT);


This goes partway to fixing bug 3684 - Add support for a pre-multiplied alpha blending mode

	blendMode = SDL_ComposeCustomBlendMode(SDL_BLENDFACTOR_ONE,
	                                       SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA,
	                                       SDL_BLENDOPERATION_ADD,
	                                       SDL_BLENDFACTOR_ONE,
	                                       SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA,
	                                       SDL_BLENDOPERATION_ADD);
This commit is contained in:
Sam Lantinga 2017-08-14 05:51:44 -07:00
parent f8e1874d01
commit c59d9923b3
16 changed files with 718 additions and 778 deletions

View file

@ -659,3 +659,4 @@ SDL_DYNAPI_PROC(SDL_JoystickID,SDL_JoystickGetDeviceInstanceID,(int a),(a),retur
SDL_DYNAPI_PROC(size_t,SDL_utf8strlen,(const char *a),(a),return)
SDL_DYNAPI_PROC(void*,SDL_LoadFile_RW,(SDL_RWops *a, size_t *b, int c),(a,b,c),return)
SDL_DYNAPI_PROC(int,SDL_wcscmp,(const wchar_t *a, const wchar_t *b),(a,b),return)
SDL_DYNAPI_PROC(SDL_BlendMode,SDL_ComposeCustomBlendMode,(SDL_BlendFactor a, SDL_BlendFactor b, SDL_BlendOperation c, SDL_BlendFactor d, SDL_BlendFactor e, SDL_BlendOperation f),(a,b,c,d,e,f),return)