SDL 2.0
SDL_blendmode.h File Reference
#include "begin_code.h"
#include "close_code.h"
+ Include dependency graph for SDL_blendmode.h:
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Enumerations

enum  SDL_BlendMode {
  SDL_BLENDMODE_NONE = 0x00000000 ,
  SDL_BLENDMODE_BLEND = 0x00000001 ,
  SDL_BLENDMODE_ADD = 0x00000002 ,
  SDL_BLENDMODE_MOD = 0x00000004 ,
  SDL_BLENDMODE_MUL = 0x00000008 ,
  SDL_BLENDMODE_INVALID = 0x7FFFFFFF
}
 
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)
 

Enumeration Type Documentation

◆ SDL_BlendFactor

The normalized factor used to multiply pixel components

Enumerator
SDL_BLENDFACTOR_ZERO 

0, 0, 0, 0

SDL_BLENDFACTOR_ONE 

1, 1, 1, 1

SDL_BLENDFACTOR_SRC_COLOR 

srcR, srcG, srcB, srcA

SDL_BLENDFACTOR_ONE_MINUS_SRC_COLOR 

1-srcR, 1-srcG, 1-srcB, 1-srcA

SDL_BLENDFACTOR_SRC_ALPHA 

srcA, srcA, srcA, srcA

SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA 

1-srcA, 1-srcA, 1-srcA, 1-srcA

SDL_BLENDFACTOR_DST_COLOR 

dstR, dstG, dstB, dstA

SDL_BLENDFACTOR_ONE_MINUS_DST_COLOR 

1-dstR, 1-dstG, 1-dstB, 1-dstA

SDL_BLENDFACTOR_DST_ALPHA 

dstA, dstA, dstA, dstA

SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA 

1-dstA, 1-dstA, 1-dstA, 1-dstA

Definition at line 78 of file SDL_blendmode.h.

79{
80 SDL_BLENDFACTOR_ZERO = 0x1, /**< 0, 0, 0, 0 */
81 SDL_BLENDFACTOR_ONE = 0x2, /**< 1, 1, 1, 1 */
82 SDL_BLENDFACTOR_SRC_COLOR = 0x3, /**< srcR, srcG, srcB, srcA */
83 SDL_BLENDFACTOR_ONE_MINUS_SRC_COLOR = 0x4, /**< 1-srcR, 1-srcG, 1-srcB, 1-srcA */
84 SDL_BLENDFACTOR_SRC_ALPHA = 0x5, /**< srcA, srcA, srcA, srcA */
85 SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA = 0x6, /**< 1-srcA, 1-srcA, 1-srcA, 1-srcA */
86 SDL_BLENDFACTOR_DST_COLOR = 0x7, /**< dstR, dstG, dstB, dstA */
87 SDL_BLENDFACTOR_ONE_MINUS_DST_COLOR = 0x8, /**< 1-dstR, 1-dstG, 1-dstB, 1-dstA */
88 SDL_BLENDFACTOR_DST_ALPHA = 0x9, /**< dstA, dstA, dstA, dstA */
89 SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA = 0xA /**< 1-dstA, 1-dstA, 1-dstA, 1-dstA */
SDL_BlendFactor
@ SDL_BLENDFACTOR_ONE_MINUS_SRC_COLOR
@ SDL_BLENDFACTOR_ZERO
@ SDL_BLENDFACTOR_SRC_COLOR
@ SDL_BLENDFACTOR_SRC_ALPHA
@ SDL_BLENDFACTOR_ONE_MINUS_DST_COLOR
@ SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA
@ SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA
@ SDL_BLENDFACTOR_DST_ALPHA
@ SDL_BLENDFACTOR_DST_COLOR
@ SDL_BLENDFACTOR_ONE

◆ SDL_BlendMode

CategoryBlendmode

Header file declaring the SDL_BlendMode enumeration The blend mode used in SDL_RenderCopy() and drawing operations.

Enumerator
SDL_BLENDMODE_NONE 

no blending dstRGBA = srcRGBA

SDL_BLENDMODE_BLEND 

alpha blending dstRGB = (srcRGB * srcA) + (dstRGB * (1-srcA)) dstA = srcA + (dstA * (1-srcA))

SDL_BLENDMODE_ADD 

additive blending dstRGB = (srcRGB * srcA) + dstRGB dstA = dstA

SDL_BLENDMODE_MOD 

color modulate dstRGB = srcRGB * dstRGB dstA = dstA

SDL_BLENDMODE_MUL 

color multiply dstRGB = (srcRGB * dstRGB) + (dstRGB * (1-srcA)) dstA = dstA

SDL_BLENDMODE_INVALID 

Definition at line 40 of file SDL_blendmode.h.

41{
42 SDL_BLENDMODE_NONE = 0x00000000, /**< no blending
43 dstRGBA = srcRGBA */
44 SDL_BLENDMODE_BLEND = 0x00000001, /**< alpha blending
45 dstRGB = (srcRGB * srcA) + (dstRGB * (1-srcA))
46 dstA = srcA + (dstA * (1-srcA)) */
47 SDL_BLENDMODE_ADD = 0x00000002, /**< additive blending
48 dstRGB = (srcRGB * srcA) + dstRGB
49 dstA = dstA */
50 SDL_BLENDMODE_MOD = 0x00000004, /**< color modulate
51 dstRGB = srcRGB * dstRGB
52 dstA = dstA */
53 SDL_BLENDMODE_MUL = 0x00000008, /**< color multiply
54 dstRGB = (srcRGB * dstRGB) + (dstRGB * (1-srcA))
55 dstA = dstA */
56 SDL_BLENDMODE_INVALID = 0x7FFFFFFF
57
58 /* Additional custom blend modes can be returned by SDL_ComposeCustomBlendMode() */
59
SDL_BlendMode
@ SDL_BLENDMODE_NONE
@ SDL_BLENDMODE_ADD
@ SDL_BLENDMODE_BLEND
@ SDL_BLENDMODE_INVALID
@ SDL_BLENDMODE_MUL
@ SDL_BLENDMODE_MOD

◆ SDL_BlendOperation

The blend operation used when combining source and destination pixel components

Enumerator
SDL_BLENDOPERATION_ADD 

dst + src: supported by all renderers

SDL_BLENDOPERATION_SUBTRACT 

src - dst : supported by D3D9, D3D11, OpenGL, OpenGLES

SDL_BLENDOPERATION_REV_SUBTRACT 

dst - src : supported by D3D9, D3D11, OpenGL, OpenGLES

SDL_BLENDOPERATION_MINIMUM 

min(dst, src) : supported by D3D9, D3D11

SDL_BLENDOPERATION_MAXIMUM 

max(dst, src) : supported by D3D9, D3D11

Definition at line 66 of file SDL_blendmode.h.

67{
68 SDL_BLENDOPERATION_ADD = 0x1, /**< dst + src: supported by all renderers */
69 SDL_BLENDOPERATION_SUBTRACT = 0x2, /**< src - dst : supported by D3D9, D3D11, OpenGL, OpenGLES */
70 SDL_BLENDOPERATION_REV_SUBTRACT = 0x3, /**< dst - src : supported by D3D9, D3D11, OpenGL, OpenGLES */
71 SDL_BLENDOPERATION_MINIMUM = 0x4, /**< min(dst, src) : supported by D3D9, D3D11 */
72 SDL_BLENDOPERATION_MAXIMUM = 0x5 /**< max(dst, src) : supported by D3D9, D3D11 */
SDL_BlendOperation
@ SDL_BLENDOPERATION_MAXIMUM
@ SDL_BLENDOPERATION_MINIMUM
@ SDL_BLENDOPERATION_REV_SUBTRACT
@ SDL_BLENDOPERATION_ADD
@ SDL_BLENDOPERATION_SUBTRACT

Function Documentation

◆ SDL_ComposeCustomBlendMode()

SDL_BlendMode SDL_ComposeCustomBlendMode ( SDL_BlendFactor  srcColorFactor,
SDL_BlendFactor  dstColorFactor,
SDL_BlendOperation  colorOperation,
SDL_BlendFactor  srcAlphaFactor,
SDL_BlendFactor  dstAlphaFactor,
SDL_BlendOperation  alphaOperation 
)
extern

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:

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 all operations with all factors. However, some factors produce unexpected results with SDL_BLENDOPERATION_MINIMUM and SDL_BLENDOPERATION_MAXIMUM.
  • direct3d11: Same as Direct3D 9.
  • 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.

Parameters
srcColorFactorthe SDL_BlendFactor applied to the red, green, and blue components of the source pixels.
dstColorFactorthe SDL_BlendFactor applied to the red, green, and blue components of the destination pixels.
colorOperationthe SDL_BlendOperation used to combine the red, green, and blue components of the source and destination pixels.
srcAlphaFactorthe SDL_BlendFactor applied to the alpha component of the source pixels.
dstAlphaFactorthe SDL_BlendFactor applied to the alpha component of the destination pixels.
alphaOperationthe 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.
See also
SDL_SetRenderDrawBlendMode
SDL_GetRenderDrawBlendMode
SDL_SetTextureBlendMode
SDL_GetTextureBlendMode