diff options
Diffstat (limited to 'src/mesa/drivers/dos/dmesa.c')
| -rw-r--r-- | src/mesa/drivers/dos/dmesa.c | 33 |
1 files changed, 25 insertions, 8 deletions
diff --git a/src/mesa/drivers/dos/dmesa.c b/src/mesa/drivers/dos/dmesa.c index 73b47569d9..5d2cfb8b2b 100644 --- a/src/mesa/drivers/dos/dmesa.c +++ b/src/mesa/drivers/dos/dmesa.c @@ -73,6 +73,7 @@ struct dmesa_visual { GLvisual gl_visual; GLboolean db_flag; /* double buffered? */ GLboolean rgb_flag; /* RGB mode? */ + GLboolean sw_alpha; /* use Mesa's alpha buffer? */ GLuint depth; /* bits per pixel (1, 8, 24, etc) */ #ifdef MATROX int stride_in_pixels; @@ -1335,7 +1336,7 @@ DMesaVisual DMesaCreateVisual (GLint width, GLint refresh, GLboolean dbFlag, GLboolean rgbFlag, - GLboolean alphaFlag, + GLint alphaSize, GLint depthSize, GLint stencilSize, GLint accumSize) @@ -1343,6 +1344,7 @@ DMesaVisual DMesaCreateVisual (GLint width, #ifndef FX DMesaVisual v; GLint redBits, greenBits, blueBits, alphaBits, indexBits; + GLboolean sw_alpha; #ifndef MATROX if (!dbFlag) { @@ -1370,6 +1372,7 @@ DMesaVisual DMesaCreateVisual (GLint width, blueBits = 8; break; case 15: + alphaBits = 1; redBits = 5; greenBits = 5; blueBits = 5; @@ -1391,6 +1394,23 @@ DMesaVisual DMesaCreateVisual (GLint width, } } + /* Okay, + * `alphaBits' is what we can provide + * `alphaSize' is what app requests + * + * Note that alpha buffering is required only if destination alpha is used + * in alpha blending; alpha blending modes that do not use destination alpha + * can be used w/o alpha buffer. + * + * We will use whatever ALPHA app requests. Later, in `CreateBuffer' we'll + * instruct Mesa to use its own ALPHA buffer, by passing a non-FALSE value + * for ALPHA to `_mesa_initialize_framebuffer'. + * + * Basically, 32bit modes provide ALPHA storage, but can we rely on this? + */ + alphaBits = alphaSize; + sw_alpha = (alphaBits > 0); + #ifndef MATROX if ((colDepth=vl_video_init(width, height, colDepth, rgbFlag, refresh)) <= 0) { return NULL; @@ -1401,10 +1421,6 @@ DMesaVisual DMesaCreateVisual (GLint width, } #endif - if (alphaFlag && (alphaBits==0)) { - alphaBits = 8; - } - if ((v=(DMesaVisual)CALLOC_STRUCT(dmesa_visual)) != NULL) { /* Create core visual */ _mesa_initialize_visual((GLvisual *)v, @@ -1421,12 +1437,13 @@ DMesaVisual DMesaCreateVisual (GLint width, accumSize, /* accumRed */ accumSize, /* accumGreen */ accumSize, /* accumBlue */ - alphaFlag?accumSize:0, /* accumAlpha */ + alphaBits?accumSize:0, /* accumAlpha */ 1); /* numSamples */ v->depth = colDepth; v->db_flag = dbFlag; v->rgb_flag = rgbFlag; + v->sw_alpha = sw_alpha; v->zbuffer = (depthSize > 0) ? 1 : 0; #ifdef MATROX @@ -1451,7 +1468,7 @@ DMesaVisual DMesaCreateVisual (GLint width, if (depthSize > 0) { fx_attrib[i++] = FXMESA_DEPTH_SIZE; fx_attrib[i++] = depthSize; } if (stencilSize > 0) { fx_attrib[i++] = FXMESA_STENCIL_SIZE; fx_attrib[i++] = stencilSize; } if (accumSize > 0) { fx_attrib[i++] = FXMESA_ACCUM_SIZE; fx_attrib[i++] = accumSize; } - if (alphaFlag) { fx_attrib[i++] = FXMESA_ALPHA_SIZE; fx_attrib[i++] = 1; } + if (alphaSize) { fx_attrib[i++] = FXMESA_ALPHA_SIZE; fx_attrib[i++] = alphaSize; } fx_attrib[i++] = FXMESA_COLORDEPTH; fx_attrib[i++] = colDepth; fx_attrib[i] = FXMESA_NONE; @@ -1493,7 +1510,7 @@ DMesaBuffer DMesaCreateBuffer (DMesaVisual visual, visual->zbuffer == 1, ((GLvisual *)visual)->stencilBits > 0, ((GLvisual *)visual)->accumRedBits > 0, - ((GLvisual *)visual)->alphaBits > 0); + visual->sw_alpha); b->xpos = xpos; b->ypos = ypos; b->width = width; |