/*
* Compute attenuated point sizes
*/
static GLboolean run_point_stage( GLcontext *ctx,
struct gl_pipeline_stage *stage )
{
struct point_stage_data *store = POINT_STAGE_DATA(stage);
struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
const GLfloat (*eye)[4] = (const GLfloat (*)[4]) VB->EyePtr->data;
const GLfloat p0 = ctx->Point.Params[0];
const GLfloat p1 = ctx->Point.Params[1];
const GLfloat p2 = ctx->Point.Params[2];
const GLfloat pointSize = ctx->Point._Size;
GLfloat (*size)[4] = store->PointSize.data;
GLuint i;
if (stage->changed_inputs) {
/* XXX do threshold and min/max clamping here? */
for (i = 0; i < VB->Count; i++) {
const GLfloat dist = -eye[i][2];
/* GLfloat dist = GL_SQRT(pos[0]*pos[0]+pos[1]*pos[1]+pos[2]*pos[2]);*/
size[i][0] = pointSize / (p0 + dist * (p1 + dist * p2));
}
}
VB->PointSizePtr = &store->PointSize;
return GL_TRUE;
}
/**
* Compute point size for each vertex from the vertex eye-space Z
* coordinate and the point size attenuation factors.
* Only done when point size attenuation is enabled and vertex program is
* disabled.
*/
static GLboolean
run_point_stage(struct gl_context *ctx, struct tnl_pipeline_stage *stage)
{
if (ctx->Point._Attenuated && !ctx->VertexProgram._Current) {
struct point_stage_data *store = POINT_STAGE_DATA(stage);
struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
const GLfloat *eyeCoord = (GLfloat *) VB->EyePtr->data + 2;
const GLint eyeCoordStride = VB->EyePtr->stride / sizeof(GLfloat);
const GLfloat p0 = ctx->Point.Params[0];
const GLfloat p1 = ctx->Point.Params[1];
const GLfloat p2 = ctx->Point.Params[2];
const GLfloat pointSize = ctx->Point.Size;
GLfloat (*size)[4] = store->PointSize.data;
GLuint i;
for (i = 0; i < VB->Count; i++) {
const GLfloat dist = FABSF(*eyeCoord);
const GLfloat q = p0 + dist * (p1 + dist * p2);
const GLfloat atten = (q != 0.0F) ? INV_SQRTF(q) : 1.0F;
size[i][0] = pointSize * atten; /* clamping done in rasterization */
eyeCoord += eyeCoordStride;
}
VB->AttribPtr[_TNL_ATTRIB_POINTSIZE] = &store->PointSize;
}
return GL_TRUE;
}
static void free_point_data( struct gl_pipeline_stage *stage )
{
struct point_stage_data *store = POINT_STAGE_DATA(stage);
if (store) {
_mesa_vector4f_free( &store->PointSize );
FREE( store );
stage->privatePtr = 0;
}
}
static GLboolean
alloc_point_data(struct gl_context *ctx, struct tnl_pipeline_stage *stage)
{
struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
struct point_stage_data *store;
stage->privatePtr = malloc(sizeof(*store));
store = POINT_STAGE_DATA(stage);
if (!store)
return GL_FALSE;
_mesa_vector4f_alloc( &store->PointSize, 0, VB->Size, 32 );
return GL_TRUE;
}
static GLboolean alloc_point_data( GLcontext *ctx,
struct gl_pipeline_stage *stage )
{
struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
struct point_stage_data *store;
stage->privatePtr = MALLOC(sizeof(*store));
store = POINT_STAGE_DATA(stage);
if (!store)
return GL_FALSE;
_mesa_vector4f_alloc( &store->PointSize, 0, VB->Size, 32 );
/* Now run the stage.
*/
stage->run = run_point_stage;
return stage->run( ctx, stage );
}
