Utilisation de CompositeTag

Utilisation du mode de composition d'AmigaOS 4.1

Alain Thellier nous explique l'utilisation du mode de composition d'AmigaOS 4.1.


CompositeTags marche de 2 manières

1) Comme le blitter il utilise des surfaces rectangulaires (genre x y haut large) et les blitte avec transparence alpha dans une autre bitmap 
==> je n'ai jamais utilisé cette façon de faire

2) Il trace des triangles de forme quelconque venant d'une bitmap dans une autre bitmap avec transparence. C'est pratiquement identique à ce que fait OpenGL (ou Warp3D) avec :
glVertexPointer(...); 
glTexCoordPointer(...); 
glDrawArrays(GL_TRIANGLES,0,TRInb*3); 
Voir une doc GL si besoin.... 

C'est ce que j'utilise dans CompositePOC (en combinant 2 triangles pour tracer un rectangle) et me permet de les mettre dans N'IMPORTE quelle position,les tourner, les mettre de biais, les redimensionner, etc.... 

Donc P contient le tableau avec les coordonnées x y des points des tris 

TRInb le nombre de triangles (2 pour simuler un rectangle) 

COMPVF_STW0_Present indique que les coordonnées de textures s t w sont fournies aussi (similaire au u v w d'OpenGL mais dans l'espace pixels et non pas 0.0 à 1.0 ) 
struct XYSTW_Vertex3D { 
float x, y; 
float s, t, w; 
}; 

NAME 
CompositeTagList - Compose one bitmap onto another (V53) 

SYNOPSIS 
uint32 CompositeTagList(uint32 operator, struct BitMap *Source, 
struct BitMap *Dest, struct TagItem *tags); 

uint32 CompositeTags(uint32 operator, struct BitMap *Source, 
struct BitMap *Dest, ...); 

FUNCTION 
This function implements Porter/Duff image compositing. If possible, the operation will be hardware accelerated. 

The function composes the bitmap pointed to by Source onto the bitmap pointed to by Dest, using the specified operator. 

Color values in the bitmaps are pre-multiplied with the alpha values (or left unmodified if no alpha is present) before composition. The most common operator is COMPOSITE_Src_Over_Dest, which, if the destination's alpha value is 1, performs a standard OpenGL-style linear blend between the Source and Destination bitmaps based on the source alpha values (i.e. a "transparent blit"). 

For the purpose of the operation, this is the order in which the modifiers are applied: 

- The source rectangle specifies a sub-portion of the source bitmap that becomes the source operand. Note that ONLY the source rectangle is used for this, i.e for all intent and purpose this is equivalent to specifying a bitmap that only contains the pixels in the source rectangle. 

- The destination operand is ALWAYS the complete destination bitmap. However, no pixel outside the destination rectangle is modified. Likewise, the OffsetX and OffsetY values specify coordinates relative to the top left pixel of the destination bitmap, NOT the destination rectangle. 

- The scale factors are applied after the source rectangle is "cut" from the source bitmap. This enlarges or shrinks the source operand to a new size, doubling or removing pixels as needed, and possibly filtering them. For all intent and purpose this is equivalent to providing a bitmap that contains a scaled (and possibly filtered) image of the original source rectangle. 

- After scaling, the resulting pixels are composed into the destination bitmap one by one using the specified operator. Asmentioned previously, no pixel outside the destination bitmap's destination rectangle are modified; the result of the compose operation there is discarded (this process is commonly called "clipping", although the term "sciscoring" is more adequate). 

- Exactly the same method is used for any alpha mask specified. 

Please refer to the SDK documentation and example code for a more in-depth discussion of the function and Porter/Duff style image composition in general. 

INPUTS 
operator - the Porter/Duff image composition operator. Please refer to graphics/composite.h for a list of operators, and the SDK documentation for their meaning. 

Source - The source bitmap. The bitmap may or may not have an Alpha channel. If it hasn't got one, then an alpha of one is assumed. The tag items may influence the interpretation of the alpha channel as well. The bitmap must be BMF_DISPLAYABLE to be able to use hardware acceleration, and it must be a compatible format, otherwise software blending is used. 

Dest - The destination bitmap. The same restrictions apply as with the Source bitmap. 

tags - A tag list with additional parameters. Some of the tag items accept fix point real numbers. These are 32 bit integers with the upper 16 bit representing the decimal part of the number, and the lower 16 bits representing the fractional part. To convert from a float to a fixpoint number, simply multiply 0x00010000 by the floating point number and typecast the result to an int32. 

Currently, the following tag items are possible: 

COMPTAG_SrcX (uint32) 

The X coordinate of a subrectangle on the source bitmap. If a subrectangle is specified, only that part of the bitmap is used for the compositing operation. Default is 0. 

COMPTAG_SrcY (uint32) 

The Y coordinate of a subrectangle on the source bitmap. If a subrectangle is specified, only that part of the bitmap is used for the compositing operation. Default is 0. 

COMPTAG_SrcWidth (uint32) 

The width of a subrectangle on the source bitmap. If a subrectangle is specified, only that part of the bitmap is used for the compositing operation. Default is the width of the source bitmap. 

COMPTAG_SrcHeight (uint32) 

The height of a subrectangle on the source bitmap. If a subrectangle is specified, only that part of the bitmap is used for the compositing operation. Default is the height of the source bitmap. 

COMPTAG_DestX (uint32) 

The X coordinate of a subrectangle on the destination bitmap. This rectangle specifies the area of the bitmap that is affected by the operation. In no case are pixels outside of this area affected by the operation. Default is 0. 

COMPTAG_DestY (uint32) 

The Y coordinate of a subrectangle on the destination bitmap. This rectangle specifies the area of the bitmap that is affected by the operation. In no case are pixels outside of this area affected by theoperation. Default is 0. 

COMPTAG_DestWidth (uint32) 

The width of a subrectangle on the destination bitmap. This rectangle specifies the area of the bitmap that is affected by the operation. In no case are pixels outside of this area affected by the operation. Default is the width of the destination bitmap. 

COMPTAG_DestHeight (uint32) 

The height of a subrectangle on the destination bitmap. This rectangle specifies the area of the bitmap that is affected by the operation. In no case are pixels outside of this area affected by the operation. Default is the height of the destination bitmap. 

COMPTAG_SrcAlpha (fixpoint) 

A constant alpha factor for the source bitmap. If the COMPFLAG_SrcAlphaOverride flag is given (see below) this value replaces any alpha channel or mask that may be present in the bitmap itself or specified via a tag item. If the COMPFLAG_SrcAlphaOverride flag is not given, then the alpha channel of the source bitmap is multiplied with this value. This tag can be used to implement the Porter/Duff fade and darken operators. The default value is 1.0. Setting any value outside the interval of zero to one inclusive yields undefined results. 

COMPTAG_DestAlpha (fixpoint) 

A constant alpha factor for the destination bitmap. If the COMPFLAG_DestAlphaOverride flag is given (see below) this value replaces any alpha channel or mask that may be present in the bitmap itself or specified via a tag item. If the COMPFLAG_DestAlphaOverride flag is not given, then the alpha channel of the source bitmap is multiplied with this value. This tag can be used to implement the Porter/Duff fade and darken operators. The default value is 1.0f. Setting any value outside the interval of zero to one inclusive yields undefined results. 

COMPTAG_ScaleX (fixpoint) 

A floating-point scale factor by which the source bitmap resp. the subrectangle of the source bitmap should be scaled horizontally before the operation is executed. A value of 1.0f means no scaling. Values greater than one enlarge the bitmap, while values between zero and one shrink it. Values less than or equal to zero are illegal and will result in the function to fail. Defaults to 1.0f (no scaling) 

COMPTAG_ScaleY (fixpoint) 

A floating-point scale factor by which the source bitmap resp. the subrectangle of the source bitmap should be scaled vertically before the operation is executed. A value of 1.0f means no scaling. Values greater than one enlarge the bitmap, while values between zero and one shrink it. Values less than or equal to zero are illegal and will result in the function to fail. Defaults to 1.0f (no scaling) 

COMPTAG_SrcAlphaMask (struct BitMap *) 

A pointer to an (alternative) alpha channel for the source bitmap. If specified, alpha information in the source bitmap is ignored. 

COMPTAG_DestAlphaMask (struct BitMap *) 

A pointer to an (alternative) alpha channel for the destination bitmap. If specified, alpha information in the destination is ignored. 

COMPTAG_SrcAlphaX (uint32) 
COMPTAG_SrcAlphaY (uint32) 

The X and Y coordinates of a subrectangle on the alpha channel bitmap for the source. The width and height of the rectangle are the same as the COMPTAG_SrcWidth and COMPTAG_SrcHeight. Defaults to zero. 

COMPTAG_DestAlphaX (uint32) 
COMPTAG_DestAlphaY (uint32) 

The X and Y coordinates of a subrectangle on the alpha channel bitmap for the destination. The width and height of the rectangle are the same as the COMPTAG_SrcWidth and COMPTAG_SrcHeight. Defaults to zero. 

COMPTAG_Flags (uint32) 

A bit mask specifying a number of flag bits that further modify the operation of this call. Currently, the following flags are defined: 

COMPFLAG_SrcAlphaOverride 
COMPFLAG_DestAlphaOverride 
If either is set, the source respectively destination alpha factor specified with COMPTAG_SrcAlpha resp. COMPTAG_DestAlpha overrides the alpha value in the bitmap or alpha mask, i.e. the alpha channel is assumed to be a constant value as specified. If the respective bit is not set, source resp. destination alpha channel values are multiplied with the value specified by the COMPTAG_SrcAlpha/COMPTAG_DestAlpha tag. 

COMPFLAG_SrcFilter 
If set, then bilinear filtering is applied to the source bitmap to smooth out any artifacts introduced by scaling. Filtering will have a slight but negligible performance impact on hardware acceleration (usually this will be so small it cannot be noticed), but might have a severe impact when using software. The software implementation may ignore this flag. 

COMPFLAG_HardwareOnly 
If this flag is set and the operation cannot be performed in hardware, instead of falling back to software the operation will fail entirely.* 

COMPFLAG_IgnoreDestAlpha 
If this flag is set, the destination bitmap is assumed to be without alpha channel, i.e. Alpha is assumed to be one. On some hardware this greatly enhances the performance or reduces the overhead of the function (for example, it frees the R200 driver from allocating temporary texture storage). Use this flag whenever possible. 

COMPTAG_OffsetX (int32) 
COMPTAG_OffsetY (int32) 

Specifies the offset on the destination bitmap (NOT the destination rectangle) where the source operand should be applied. Negative coordinates are possible. By default, both tags are zero. 


RESULT 
The function returns a status code. The following values are possible: 

COMPERR_Success 
No error. The operation performed successfully. 

COMPERR_Incompatible 
The input bitmaps were incompatible for the call. This usually happens when a bitmap color format is not supported. 

COMPERR_Value 
An input value was illegal. This error is raised if e.g. the specified operator is not known, or negative coordinates are given, etc. 

COMPERR_SoftwareFallback 
The COMPFLAG_HardwareOnly flag was set but the operation was incompatible with the current hardware. 

COMPERR_OutOfMemory 
Temporary storage was required to finish the operation but could not be allocated. 

COMPERR_Generic 
An unknown error has occurred. 

SEE ALSO 
SDK examples and documentation. 

enum enPDOperator 
COMPOSITE_Clear = 0, 
COMPOSITE_Src = 1, 
COMPOSITE_Dest = 2, 
COMPOSITE_Src_Over_Dest = 3, 
COMPOSITE_Dest_Over_Src = 4, 
COMPOSITE_Src_In_Dest = 5, 
COMPOSITE_Dest_In_Src = 6, 
COMPOSITE_Src_Out_Dest = 7, 
COMPOSITE_Dest_Out_Src = 8, 
COMPOSITE_Src_Atop_Dest = 9, 
COMPOSITE_Dest_Atop_Src = 10, 
COMPOSITE_Src_Xor_Dest = 11, 
COMPOSITE_Plus = 12, 

COMPOSITE_NumOperators = 13 
}; 

/* Tag items for the Composite call */ 
#define COMPTAG_Base TAG_USER 

/* (uint32) X clip coordinate on source bitmap (defaults to 0) */ 
#define COMPTAG_SrcX (COMPTAG_Base + 0) 

/* (uint32) Y clip coordinate on source bitmap (defaults to 0) */ 
#define COMPTAG_SrcY (COMPTAG_Base + 1) 

/* (uint32) Width of clip rectangle on source (defaults to full width) */ 
#define COMPTAG_SrcWidth (COMPTAG_Base + 2) 

/* (uint32) Height of clip rectangle on source (defaults to full height) */ 
#define COMPTAG_SrcHeight (COMPTAG_Base + 3) 

/* (uint32) X clip coordinate on dest bitmap (defaults to 0) */ 
#define COMPTAG_DestX (COMPTAG_Base + 4) 

/* (uint32) Y clip coordinate on dest bitmap (defaults to 0) */ 
#define COMPTAG_DestY (COMPTAG_Base + 5) 

/* (uint32) Width of clip rectangle on dest (defaults to full width) */ 
#define COMPTAG_DestWidth (COMPTAG_Base + 6) 

/* (uint32) Height of clip rectangle on dest (defaults to full height) */ 
#define COMPTAG_DestHeight (COMPTAG_Base + 7) 

/* (fixpoint) (additional) Alpha for source bitmap (no default) */ 
#define COMPTAG_SrcAlpha (COMPTAG_Base + 8) 

/* (fixpoint) (additional) Alpha for destination bitmap (no default) */ 
#define COMPTAG_DestAlpha (COMPTAG_Base + 9) 

/* (fixpoint) X scale factor for source bitmap (defaults to 1.0) */ 
#define COMPTAG_ScaleX (COMPTAG_Base + 10) 

/* (fixpoint) Y scale factor for source bitmap (defaults to 1.0) */ 
#define COMPTAG_ScaleY (COMPTAG_Base + 11) 

/* (struct Bitmap *) Alpha mask for source. Specifying this tag overrides any 
* alpha that might be present in the source bitmap. 
*/ 
#define COMPTAG_SrcAlphaMask (COMPTAG_Base + 12) 

/* (struct Bitmap *) Alpha mask for the destination. Specifying this tag 
* overrides any alpha that might be present in the destination bitmap. 
*/ 
#define COMPTAG_DestAlphaMask (COMPTAG_Base + 13) 

/* (uint32, see defines below) Specifies a set of flags that may modify the 
* operation. See the defines below 
*/ 
#define COMPTAG_Flags (COMPTAG_Base + 18) 

/* (int32) X Coordinate on the destination bitmap that the operation should be 
* applied to. Defaults to zero. 
*/ 
#define COMPTAG_OffsetX (COMPTAG_Base + 20) 

/* (int32) Y Coordinate on the destination bitmap that the operation should be 
* applied to. Defaults to zero. 
*/ 
#define COMPTAG_OffsetY (COMPTAG_Base + 21) 

/* (struct BitMap *) when the source and/or destination bitmaps are located in 
* main memory, this tag tells the graphics system to upload the bitmaps to 
* the same board the friend bitmap is located on. 
*/ 
#define COMPTAG_FriendBitMap (COMPTAG_Base + 22) 

/* (uint32) the same as above, but a DisplayID is used as reference to the board 
* and not a bitmap. 
*/ 
#define COMPTAG_DisplayID (COMPTAG_Base + 23) 

/* (uint32) the X/Y coordinates on the src alpha map to use for compositing. If not 
* specified, use the same as the SrcX and SrcY 
*/ 
#define COMPTAG_SrcAlphaX (COMPTAG_Base + 14) 
#define COMPTAG_SrcAlphaY (COMPTAG_Base + 15) 

/* (uint32) the X/Y coordinates on the destination alpha map to use. If not 
* specified, use the DestX and DestY 
*/ 
#define COMPTAG_DestAlphaX (COMPTAG_Base + 16) 
#define COMPTAG_DestAlphaY (COMPTAG_Base + 17) 

/* 
* The following group of tag items deals with direct triangle mapping. Read the 
* autodoc for a detailed explanation 
*/ 
#define COMPTAG_VertexArray (COMPTAG_Base + 30) 
#define COMPTAG_IndexArray (COMPTAG_Base + 31) 
#define COMPTAG_VertexFormat (COMPTAG_Base + 32) 
#define COMPTAG_NumTriangles (COMPTAG_Base + 33) 

/* 
* This group of tag items can be used to specify up to four colors, either 
* as an 32 bit ARGB value, or as a set of discreet fixpoint numbers. 
* The fixpoint numbers range is 0 to 1. Specifying a fixpoint component 
* overrides the ARGB value completely. 
*/ 
#define COMPTAG_Color0 (COMPTAG_Base + 40) 
#define COMPTAG_Color1 (COMPTAG_Base + 41) 
#define COMPTAG_Color2 (COMPTAG_Base + 42) 
#define COMPTAG_Color3 (COMPTAG_Base + 43) 

#define COMPTAG_Color0_Red (COMPTAG_Base + 44) 
#define COMPTAG_Color0_Green (COMPTAG_Base + 45) 
#define COMPTAG_Color0_Blue (COMPTAG_Base + 46) 
#define COMPTAG_Color0_Alpha (COMPTAG_Base + 47) 

#define COMPTAG_Color1_Red (COMPTAG_Base + 48) 
#define COMPTAG_Color1_Green (COMPTAG_Base + 49) 
#define COMPTAG_Color1_Blue (COMPTAG_Base + 50) 
#define COMPTAG_Color1_Alpha (COMPTAG_Base + 51) 

#define COMPTAG_Color2_Red (COMPTAG_Base + 52) 
#define COMPTAG_Color2_Green (COMPTAG_Base + 53) 
#define COMPTAG_Color2_Blue (COMPTAG_Base + 54) 
#define COMPTAG_Color2_Alpha (COMPTAG_Base + 55) 

#define COMPTAG_Color3_Red (COMPTAG_Base + 56) 
#define COMPTAG_Color3_Green (COMPTAG_Base + 57) 
#define COMPTAG_Color3_Blue (COMPTAG_Base + 58) 
#define COMPTAG_Color3_Alpha (COMPTAG_Base + 59) 


/* 
* Reserved 
*/ 
#define COMPTAG_Private (COMPTAG_Base + 34) 
#define COMPTAG_Private2 (COMPTAG_Base + 35) 

/* Vertex Array format flags */ 
#define COMPVF_STW0_Present 0x02 
#define COMPVF_STW1_Present 0x04 

/* 
* Flags for the COMPTAG_Flags tag item 
* Currently defined flags are: 
* COMPFLAG_SrcAlphaOverride - If set, the value specified in SrcAlpha overrides 
* the value in the source bitmap, which means that the source bitmap is 
* assumed to have a constant alpha over the entire image. If not set, 
* the SrcAlpha value is used to modulate/scale any other alpha channel. 
* COMPFLAG_DestAlphaOverride - Like COMPFLAG_SrcAlphaOverride, for the 
* destination bitmap. 
* COMPFLAG_SrcFilter - If set, enables bilinear filtering of the source bitmap 
* while scaling. While this can improve the quality of scaled images, 
* it might cause a dramatic slowdown when the operation is emulated 
* in software. 
* COMPFLAG_DestFilter - Like COMPFLAG_SrcFilter for the destination bitmap. 
* COMPFLAG_HardwareOnly - If set, the call will fail with an error code if 
* the operation cannot be performed in hardware. Reasons for this !include! 
* software-only bitmaps, unsupported color formats, etc. 
* COMPFLAG_ForceSoftware - If set, the operation will be emulated in software 
* even if it could be performed in hardware. This is mostly useful for 
* testing purposes. Setting this overrides COMPFLAG_HardwareOnly. 
* COMPFLAG_Color1Modulate - If set, then Color 1 is used as a modulate 
* color for the src bitmap. That is, each color component of each pixel 
* in the source bitmap is multiplied with the color 1 (including its 
* alpha). All other effects stay in effect. This flag can essentially 
* be used to "tint" a bitmap in the given color 
*/ 

#define COMPFLAG_SrcAlphaOverride (1L << 0) 
#define COMPFLAG_DestAlphaOverride (1L << 1) 
#define COMPFLAG_SrcFilter (1L << 2) 
#define COMPFLAG_HardwareOnly (1L << 3) 
#define COMPFLAG_IgnoreDestAlpha (1L << 4) 
#define COMPFLAG_ForceSoftware (1L << 7) 
#define COMPFLAG_Color1Modulate (1L << 8) 

/* Helper Macros to convert to/from fixpoint numbers */ 
#define COMP_FIX_ONE 0x00010000 
#define COMP_FLOAT_TO_FIX(f) (int32)((float)COMP_FIX_ONE * f) 
#define COMP_FIX_TO_FLOAT(fix) ((float)fix / (float)COMP_FIX_ONE) 
#define COMP_FIX_TO_UINT32(fix) ((fix) / COMP_FIX_ONE) 


/* Possible constants for Source */ 
#define COMPSRC_SOLIDCOLOR ((struct BitMap *)1) 

enum enCompositeError 
COMPERR_Success = 0, 
COMPERR_Incompatible = 1, /* Incompatible bitmaps for operation */ 
COMPERR_Value = 2, /* An input value is out of range */ 
COMPERR_SoftwareFallback = 3, /* Operation would fall back to 
software emulation and hardware 
only was requested */ 
COMPERR_OutOfMemory = 4, /* The operation tried to allocate 
memory but failed */ 
COMPERR_Generic = 5, /* Some generic error has occurred */ 
COMPERR_UnknownOperator = 6, /* Unknown operator specified */ 
COMPERR_MissingInput = 7, /* Missing a mandatory tag item */ 

}; 

Il existe un possible bug qui empêche l'utilisation d'un écran comme bitmap source.

La technique 2 permet juste de positionner le rectangle dans n'importe quelle position ce qui est coolissime (ou alors de tracer des tonnes de triangles 3D pour faire un rendu 3D comme fait Wazp3D). Le plus simple est alors de reprendre du code qui marche à CompositePOC. Pour un rectangle normal on peut se contenter de la 1) mais je l'ai jamais utilisée... 

Sur P96 j'ai fait comme l'exemple de Hans avec la boing ball = pas d'avis 

Concernant les opérateurs alpha :

1) Sur la doc sur l'Alpha compositing, ce que l'on trouve sur Internet est en dessous de tout (= de zolis dessins mais pas de formules math.). Et dans le SDK y a pas grand choses non plus. Voici ce que j'ai trouvé d'utile: 

Donc Os4 supporte les opérations suivantes :
Clear
Src
Dest
Src_Over_Dest
Dest_Over_Src
Src_In_Dest
Dest_In_Src
Src_Out_Dest
Dest_Out_Src
Src_Atop_Dest
Dest_Atop_Src
Src_Xor_Dest
Plus 

Avec cette page j'ai obtenu qques formules :

ADD Saturate(S + D) 
CLEAR DstA= 0 DstC= 0; 
DARKEN DstA= SrcA + DstA - SrcA*DstA DstC= SrcC*(1 - DstA) + DstC*(1 - SrcA) + min(SrcC,DstC); 
DST DstA= DstA DstC= DstC; 
DST_ATOP DstA= SrcA DstC= SrcA * DstC + SrcC * (1 - DstA); 
DST_IN DstA= SrcA * DstA DstC= SrcA * DstC; 
DST_OUT DstA= DstA * (1 - SrcA) DstC= DstC * (1 - SrcA); 
DST_OVER DstA= SrcA + (1 - SrcA)*DstA DstC= Rc = DstC + (1 - DstA)*SrcC; 
LIGHTEN DstA= SrcA + DstA - SrcA*DstA DstC= SrcC*(1 - DstA) + DstC*(1 - SrcA) + max(SrcC,DstC); 
MULTIPLY DstA= SrcA * DstA DstC= SrcC * DstC; 
OVERLAY ?? 
SCREEN DstA= SrcA + DstA - SrcA * DstA DstC= SrcC + DstC - SrcC * DstC; 
SRC DstA= SrcA DstC= SrcC; 
SRC_ATOP DstA= DstA DstC= SrcC * DstA + (1 - SrcA) * DstC; 
SRC_IN DstA= SrcA * DstA DstC= SrcC * DstA; 
SRC_OUT DstA= SrcA * (1 - DstA) DstC= SrcC * (1 - DstA); 
SRC_OVER DstA= SrcA + (1 - SrcA)*DstA DstC= Rc = SrcC + (1 - SrcA)*DstC; 
XOR DstA= SrcA + DstA - 2 * SrcA * DstA DstC= SrcC * (1 - DstA) + (1 - SrcA) * DstC; 

Voir aussi dans 
Aminet/wazp3D/soft3d_compositing.c

On en conclut que SRC_OVER(_Dst) correspondrait au SRC_ALPHA,ONE_MINUS_SRC_ALPHA la formule classique de transparence d'OpenGL ou Warp3D. Il faut ensuite voir ce que font VRAIMENT les COMPFLAG_SrcAlphaOverride et COMPFLAG_DestAlphaOverride,et autres si on les ajoute.

Le mode de composition est utilisé pour Wazp3D avec quelques limitations néanmoins :

Dans Chromium, par exemple, certaines textures/couleurs sont manquantes car en Compositing2D on ne peut pas appliquer une couleur à une texture (ce que j'appelle Coloring GL) comme avec OpenGL/Warp3D (GL_MODULATE existe pas) éventuellement on peut tracer la texture puis faire une deuxième passe de couleur transparente mais alors ça merde si la tex a des parties transparentes (car colorées aussi) 

On sera jamais 100% identique à Warp3D mais des améliorations sont très possibles sur ce sujet.

Non ce qui manque cruellement c'est le Zbuffer : si le programme l'utilise alors ça va mal fonctionner. S'il ne l'utilise pas comme FPSE,WipeOut etc... alors ça marche nickel.





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