SDL 3.0
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Macros | |
#define | SDL_BLENDMODE_NONE 0x00000000u |
#define | SDL_BLENDMODE_BLEND 0x00000001u |
#define | SDL_BLENDMODE_BLEND_PREMULTIPLIED 0x00000010u |
#define | SDL_BLENDMODE_ADD 0x00000002u |
#define | SDL_BLENDMODE_ADD_PREMULTIPLIED 0x00000020u |
#define | SDL_BLENDMODE_MOD 0x00000004u |
#define | SDL_BLENDMODE_MUL 0x00000008u |
#define | SDL_BLENDMODE_INVALID 0x7FFFFFFFu |
Typedefs | |
typedef Uint32 | SDL_BlendMode |
Enumerations | |
enum | SDL_BlendOperation { SDL_BLENDOPERATION_ADD = 0x1 , SDL_BLENDOPERATION_SUBTRACT = 0x2 , SDL_BLENDOPERATION_REV_SUBTRACT = 0x3 , SDL_BLENDOPERATION_MINIMUM = 0x4 , SDL_BLENDOPERATION_MAXIMUM = 0x5 } |
enum | SDL_BlendFactor { SDL_BLENDFACTOR_ZERO = 0x1 , SDL_BLENDFACTOR_ONE = 0x2 , SDL_BLENDFACTOR_SRC_COLOR = 0x3 , SDL_BLENDFACTOR_ONE_MINUS_SRC_COLOR = 0x4 , SDL_BLENDFACTOR_SRC_ALPHA = 0x5 , SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA = 0x6 , SDL_BLENDFACTOR_DST_COLOR = 0x7 , SDL_BLENDFACTOR_ONE_MINUS_DST_COLOR = 0x8 , SDL_BLENDFACTOR_DST_ALPHA = 0x9 , SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA = 0xA } |
Functions | |
SDL_BlendMode | SDL_ComposeCustomBlendMode (SDL_BlendFactor srcColorFactor, SDL_BlendFactor dstColorFactor, SDL_BlendOperation colorOperation, SDL_BlendFactor srcAlphaFactor, SDL_BlendFactor dstAlphaFactor, SDL_BlendOperation alphaOperation) |
#define SDL_BLENDMODE_ADD 0x00000002u |
additive blending: dstRGB = (srcRGB * srcA) + dstRGB, dstA = dstA
Definition at line 57 of file SDL_blendmode.h.
#define SDL_BLENDMODE_ADD_PREMULTIPLIED 0x00000020u |
pre-multiplied additive blending: dstRGB = srcRGB + dstRGB, dstA = dstA
Definition at line 58 of file SDL_blendmode.h.
#define SDL_BLENDMODE_BLEND 0x00000001u |
alpha blending: dstRGB = (srcRGB * srcA) + (dstRGB * (1-srcA)), dstA = srcA + (dstA * (1-srcA))
Definition at line 55 of file SDL_blendmode.h.
#define SDL_BLENDMODE_BLEND_PREMULTIPLIED 0x00000010u |
pre-multiplied alpha blending: dstRGBA = srcRGBA + (dstRGBA * (1-srcA))
Definition at line 56 of file SDL_blendmode.h.
#define SDL_BLENDMODE_INVALID 0x7FFFFFFFu |
Definition at line 61 of file SDL_blendmode.h.
#define SDL_BLENDMODE_MOD 0x00000004u |
color modulate: dstRGB = srcRGB * dstRGB, dstA = dstA
Definition at line 59 of file SDL_blendmode.h.
#define SDL_BLENDMODE_MUL 0x00000008u |
color multiply: dstRGB = (srcRGB * dstRGB) + (dstRGB * (1-srcA)), dstA = dstA
Definition at line 60 of file SDL_blendmode.h.
#define SDL_BLENDMODE_NONE 0x00000000u |
no blending: dstRGBA = srcRGBA
Definition at line 54 of file SDL_blendmode.h.
typedef Uint32 SDL_BlendMode |
Blend modes decide how two colors will mix together. There are both standard modes for basic needs and a means to create custom modes, dictating what sort of math to do on what color components. A set of blend modes used in drawing operations.
These predefined blend modes are supported everywhere.
Additional values may be obtained from SDL_ComposeCustomBlendMode.
Definition at line 52 of file SDL_blendmode.h.
enum SDL_BlendFactor |
The normalized factor used to multiply pixel components.
The blend factors are multiplied with the pixels from a drawing operation (src) and the pixels from the render target (dst) before the blend operation. The comma-separated factors listed above are always applied in the component order red, green, blue, and alpha.
Definition at line 88 of file SDL_blendmode.h.
enum SDL_BlendOperation |
The blend operation used when combining source and destination pixel components.
Definition at line 69 of file SDL_blendmode.h.
SDL_BlendMode SDL_ComposeCustomBlendMode | ( | SDL_BlendFactor | srcColorFactor, |
SDL_BlendFactor | dstColorFactor, | ||
SDL_BlendOperation | colorOperation, | ||
SDL_BlendFactor | srcAlphaFactor, | ||
SDL_BlendFactor | dstAlphaFactor, | ||
SDL_BlendOperation | alphaOperation | ||
) |
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:
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. All renderers support the four blend modes listed in the SDL_BlendMode enumeration.
SDL_BLENDOPERATION_MINIMUM
and SDL_BLENDOPERATION_MAXIMUM
.SDL_BLENDOPERATION_ADD
operation with all factors. OpenGL versions 1.1, 1.2, and 1.3 do not work correctly here.SDL_BLENDOPERATION_ADD
, SDL_BLENDOPERATION_SUBTRACT
, SDL_BLENDOPERATION_REV_SUBTRACT
operations with all factors.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.
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. |
\threadsafety It is safe to call this function from any thread.