SDL_SetTextureAlphaMod

Use this function to set an additional alpha value multiplied into render copy operations.

Syntax

int SDL_SetTextureAlphaMod(SDL_Texture* texture,
                           Uint8        alpha)

Function Parameters

texture

the texture to update

alpha

the source alpha value multiplied into copy operations

Return Value

Returns 0 on success or a negative error code on failure; call SDL_GetError() for more information.

Code Examples

You can add your code example here

Remarks

When this texture is rendered, during the copy operation the source alpha value is modulated by this alpha value according to the following formula:

  • srcA = srcA * (alpha / 255)

Alpha modulation is not always supported by the renderer; it will return -1 if alpha modulation is not supported.

You can call SDL_GetRendererInfo() to fill in an SDL_RendererInfo structure with the information about the current renderer. This structure will have SDL_TEXTUREMODULATE_ALPHA set in the mod_modes mask if alpha modulation is supported.


CategoryAPI, CategoryVideo

SDL_SetTextureAlphaMod (last edited 2011-01-07 18:50:19 by SheenaSmith)

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