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

@ -79,6 +79,7 @@ struct SDL_Renderer
void (*WindowEvent) (SDL_Renderer * renderer, const SDL_WindowEvent *event);
int (*GetOutputSize) (SDL_Renderer * renderer, int *w, int *h);
SDL_bool (*SupportsBlendMode)(SDL_Renderer * renderer, SDL_BlendMode blendMode);
int (*CreateTexture) (SDL_Renderer * renderer, SDL_Texture * texture);
int (*SetTextureColorMod) (SDL_Renderer * renderer,
SDL_Texture * texture);
@ -186,6 +187,14 @@ extern SDL_RenderDriver DirectFB_RenderDriver;
extern SDL_RenderDriver PSP_RenderDriver;
extern SDL_RenderDriver SW_RenderDriver;
/* Blend mode functions */
extern SDL_BlendFactor SDL_GetBlendModeSrcColorFactor(SDL_BlendMode blendMode);
extern SDL_BlendFactor SDL_GetBlendModeDstColorFactor(SDL_BlendMode blendMode);
extern SDL_BlendOperation SDL_GetBlendModeColorOperation(SDL_BlendMode blendMode);
extern SDL_BlendFactor SDL_GetBlendModeSrcAlphaFactor(SDL_BlendMode blendMode);
extern SDL_BlendFactor SDL_GetBlendModeDstAlphaFactor(SDL_BlendMode blendMode);
extern SDL_BlendOperation SDL_GetBlendModeAlphaOperation(SDL_BlendMode blendMode);
#endif /* SDL_sysrender_h_ */
/* vi: set ts=4 sw=4 expandtab: */