/**
* Apply texture mapping to a span of fragments.
*/
void
_swrast_texture_span( struct gl_context *ctx, SWspan *span )
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);
float4_array primary_rgba;
if (!swrast->TexelBuffer) {
#ifdef _OPENMP
const GLint maxThreads = omp_get_max_threads();
#else
const GLint maxThreads = 1;
#endif
/* TexelBuffer is also global and normally shared by all SWspan
* instances; when running with multiple threads, create one per
* thread.
*/
swrast->TexelBuffer = (GLfloat *) MALLOC(maxThreads * MAX_WIDTH * 4 * sizeof(GLfloat));
if (!swrast->TexelBuffer) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "texture_combine");
return;
}
}
primary_rgba = (float4_array) malloc(span->end * 4 * sizeof(GLfloat));
if (!primary_rgba) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "texture_span");
return;
}
ASSERT(span->end <= MAX_WIDTH);
/*
* Save copy of the incoming fragment colors (the GL_PRIMARY_COLOR)
*/
if (swrast->_TextureCombinePrimary) {
GLuint i;
for (i = 0; i < span->end; i++) {
primary_rgba[i][RCOMP] = CHAN_TO_FLOAT(span->array->rgba[i][RCOMP]);
primary_rgba[i][GCOMP] = CHAN_TO_FLOAT(span->array->rgba[i][GCOMP]);
primary_rgba[i][BCOMP] = CHAN_TO_FLOAT(span->array->rgba[i][BCOMP]);
primary_rgba[i][ACOMP] = CHAN_TO_FLOAT(span->array->rgba[i][ACOMP]);
}
}
/*
* Must do all texture sampling before combining in order to
* accomodate GL_ARB_texture_env_crossbar.
*/
{
const struct gl_texture_unit *texUnit = &ctx->Texture.Unit;
if (texUnit->_ReallyEnabled) {
const GLfloat (*texcoords)[4] = (const GLfloat (*)[4])
span->array->attribs[FRAG_ATTRIB_TEX];
const struct gl_texture_object *curObj = texUnit->_Current;
GLfloat *lambda = span->array->lambda;
float4_array texels = get_texel_array(swrast);
if (curObj->Sampler.MaxAnisotropy > 1.0 &&
curObj->Sampler.MinFilter == GL_LINEAR_MIPMAP_LINEAR) {
/* sample_lambda_2d_aniso is beeing used as texture_sample_func,
* it requires the current SWspan *span as an additional parameter.
* In order to keep the same function signature, the unused lambda
* parameter will be modified to actually contain the SWspan pointer.
* This is a Hack. To make it right, the texture_sample_func
* signature and all implementing functions need to be modified.
*/
/* "hide" SWspan struct; cast to (GLfloat *) to suppress warning */
lambda = (GLfloat *)span;
}
/* Sample the texture (span->end = number of fragments) */
swrast->TextureSample( ctx, texUnit->_Current, span->end,
texcoords, lambda, texels );
}
}
/*
* OK, now apply the texture (aka texture combine/blend).
* We modify the span->color.rgba values.
*/
if (ctx->Texture.Unit._ReallyEnabled)
texture_combine(ctx, primary_rgba, swrast->TexelBuffer, span);
free(primary_rgba);
}
