2 * Mesa 3-D graphics library
4 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
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27 * Implement the effect of glColorMask and glIndexMask in software.
31 #include "main/glheader.h"
32 #include "main/macros.h"
34 #include "s_context.h"
35 #include "s_masking.h"
40 * Apply the color mask to a span of rgba values.
43 _swrast_mask_rgba_span(struct gl_context
*ctx
, struct gl_renderbuffer
*rb
,
44 SWspan
*span
, GLuint buf
)
46 const GLuint n
= span
->end
;
49 assert(n
< SWRAST_MAX_WIDTH
);
50 assert(span
->arrayMask
& SPAN_RGBA
);
52 rbPixels
= _swrast_get_dest_rgba(ctx
, rb
, span
);
55 * Do component masking.
56 * Note that we're not using span->array->mask[] here. We could...
58 if (span
->array
->ChanType
== GL_UNSIGNED_BYTE
) {
59 const GLubyte colormask
[4] = {
60 GET_COLORMASK_BIT(ctx
->Color
.ColorMask
, buf
, 0) ? 0xff : 0,
61 GET_COLORMASK_BIT(ctx
->Color
.ColorMask
, buf
, 1) ? 0xff : 0,
62 GET_COLORMASK_BIT(ctx
->Color
.ColorMask
, buf
, 2) ? 0xff : 0,
63 GET_COLORMASK_BIT(ctx
->Color
.ColorMask
, buf
, 3) ? 0xff : 0,
66 memcpy(&srcMask
, colormask
, sizeof(srcMask
));
67 const GLuint dstMask
= ~srcMask
;
68 const GLuint
*dst
= (const GLuint
*) rbPixels
;
69 GLuint
*src
= (GLuint
*) span
->array
->rgba8
;
71 for (i
= 0; i
< n
; i
++) {
72 src
[i
] = (src
[i
] & srcMask
) | (dst
[i
] & dstMask
);
75 else if (span
->array
->ChanType
== GL_UNSIGNED_SHORT
) {
76 /* 2-byte components */
77 /* XXX try to use 64-bit arithmetic someday */
78 const GLushort rMask
= GET_COLORMASK_BIT(ctx
->Color
.ColorMask
, buf
, 0) ? 0xffff : 0x0;
79 const GLushort gMask
= GET_COLORMASK_BIT(ctx
->Color
.ColorMask
, buf
, 1) ? 0xffff : 0x0;
80 const GLushort bMask
= GET_COLORMASK_BIT(ctx
->Color
.ColorMask
, buf
, 2) ? 0xffff : 0x0;
81 const GLushort aMask
= GET_COLORMASK_BIT(ctx
->Color
.ColorMask
, buf
, 3) ? 0xffff : 0x0;
82 const GLushort (*dst
)[4] = (const GLushort (*)[4]) rbPixels
;
83 GLushort (*src
)[4] = span
->array
->rgba16
;
85 for (i
= 0; i
< n
; i
++) {
86 src
[i
][RCOMP
] = (src
[i
][RCOMP
] & rMask
) | (dst
[i
][RCOMP
] & ~rMask
);
87 src
[i
][GCOMP
] = (src
[i
][GCOMP
] & gMask
) | (dst
[i
][GCOMP
] & ~gMask
);
88 src
[i
][BCOMP
] = (src
[i
][BCOMP
] & bMask
) | (dst
[i
][BCOMP
] & ~bMask
);
89 src
[i
][ACOMP
] = (src
[i
][ACOMP
] & aMask
) | (dst
[i
][ACOMP
] & ~aMask
);
93 /* 4-byte components */
94 const GLuint rMask
= GET_COLORMASK_BIT(ctx
->Color
.ColorMask
, buf
, 0) ? ~0x0 : 0x0;
95 const GLuint gMask
= GET_COLORMASK_BIT(ctx
->Color
.ColorMask
, buf
, 1) ? ~0x0 : 0x0;
96 const GLuint bMask
= GET_COLORMASK_BIT(ctx
->Color
.ColorMask
, buf
, 2) ? ~0x0 : 0x0;
97 const GLuint aMask
= GET_COLORMASK_BIT(ctx
->Color
.ColorMask
, buf
, 3) ? ~0x0 : 0x0;
98 const GLuint (*dst
)[4] = (const GLuint (*)[4]) rbPixels
;
99 GLuint (*src
)[4] = (GLuint (*)[4]) span
->array
->attribs
[VARYING_SLOT_COL0
];
101 for (i
= 0; i
< n
; i
++) {
102 src
[i
][RCOMP
] = (src
[i
][RCOMP
] & rMask
) | (dst
[i
][RCOMP
] & ~rMask
);
103 src
[i
][GCOMP
] = (src
[i
][GCOMP
] & gMask
) | (dst
[i
][GCOMP
] & ~gMask
);
104 src
[i
][BCOMP
] = (src
[i
][BCOMP
] & bMask
) | (dst
[i
][BCOMP
] & ~bMask
);
105 src
[i
][ACOMP
] = (src
[i
][ACOMP
] & aMask
) | (dst
[i
][ACOMP
] & ~aMask
);