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Diffstat (limited to 'src/mesa/pipe/softpipe/sp_quad_stencil.c')
-rw-r--r--src/mesa/pipe/softpipe/sp_quad_stencil.c288
1 files changed, 288 insertions, 0 deletions
diff --git a/src/mesa/pipe/softpipe/sp_quad_stencil.c b/src/mesa/pipe/softpipe/sp_quad_stencil.c
new file mode 100644
index 0000000000..0b37474c1a
--- /dev/null
+++ b/src/mesa/pipe/softpipe/sp_quad_stencil.c
@@ -0,0 +1,288 @@
+
+/**
+ * \brief Quad stencil testing
+ */
+
+
+#include "main/glheader.h"
+#include "main/imports.h"
+#include "sp_context.h"
+#include "sp_headers.h"
+#include "sp_surface.h"
+#include "sp_quad.h"
+#include "pipe/p_defines.h"
+
+
+/** Only 8-bit stencil supported */
+#define STENCIL_MAX 0xff
+
+
+/**
+ * Do the basic stencil test (compare stencil buffer values against the
+ * reference value.
+ *
+ * \param stencilVals the stencil values from the stencil buffer
+ * \param func the stencil func (PIPE_FUNC_x)
+ * \param ref the stencil reference value
+ * \param valMask the stencil value mask indicating which bits of the stencil
+ * values and ref value are to be used.
+ * \return mask indicating which pixels passed the stencil test
+ */
+static GLbitfield
+do_stencil_test(const GLubyte stencilVals[QUAD_SIZE], GLuint func,
+ GLbitfield ref, GLbitfield valMask)
+{
+ GLbitfield passMask = 0x0;
+ GLuint j;
+
+ ref &= valMask;
+
+ switch (func) {
+ case PIPE_FUNC_NEVER:
+ /* passMask = 0x0 */
+ break;
+ case PIPE_FUNC_LESS:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if ((stencilVals[j] & valMask) < ref) {
+ passMask |= (1 << j);
+ }
+ }
+ break;
+ case PIPE_FUNC_EQUAL:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if ((stencilVals[j] & valMask) == ref) {
+ passMask |= (1 << j);
+ }
+ }
+ break;
+ case PIPE_FUNC_LEQUAL:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if ((stencilVals[j] & valMask) <= ref) {
+ passMask |= (1 << j);
+ }
+ }
+ break;
+ case PIPE_FUNC_GREATER:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if ((stencilVals[j] & valMask) > ref) {
+ passMask |= (1 << j);
+ }
+ }
+ break;
+ case PIPE_FUNC_NOTEQUAL:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if ((stencilVals[j] & valMask) != ref) {
+ passMask |= (1 << j);
+ }
+ }
+ break;
+ case PIPE_FUNC_GEQUAL:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if ((stencilVals[j] & valMask) >= ref) {
+ passMask |= (1 << j);
+ }
+ }
+ break;
+ case PIPE_FUNC_ALWAYS:
+ passMask = MASK_ALL;
+ break;
+ default:
+ assert(0);
+ }
+
+ return passMask;
+}
+
+
+/**
+ * Apply the stencil operator to stencil values.
+ *
+ * \param stencilVals the stencil buffer values (read and written)
+ * \param mask indicates which pixels to update
+ * \param op the stencil operator (PIPE_STENCIL_OP_x)
+ * \param ref the stencil reference value
+ * \param wrtMask writemask controlling which bits are changed in the
+ * stencil values
+ */
+static void
+apply_stencil_op(GLubyte stencilVals[QUAD_SIZE],
+ GLbitfield mask, GLuint op, GLubyte ref, GLubyte wrtMask)
+{
+ GLuint j;
+ GLubyte newstencil[QUAD_SIZE];
+
+ for (j = 0; j < QUAD_SIZE; j++) {
+ newstencil[j] = stencilVals[j];
+ }
+
+ switch (op) {
+ case PIPE_STENCIL_OP_KEEP:
+ /* no-op */
+ break;
+ case PIPE_STENCIL_OP_ZERO:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if (mask & (1 << j)) {
+ newstencil[j] = 0;
+ }
+ }
+ break;
+ case PIPE_STENCIL_OP_REPLACE:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if (mask & (1 << j)) {
+ newstencil[j] = ref;
+ }
+ }
+ break;
+ case PIPE_STENCIL_OP_INCR:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if (mask & (1 << j)) {
+ if (stencilVals[j] < STENCIL_MAX) {
+ newstencil[j] = stencilVals[j] + 1;
+ }
+ }
+ }
+ break;
+ case PIPE_STENCIL_OP_DECR:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if (mask & (1 << j)) {
+ if (stencilVals[j] > 0) {
+ newstencil[j] = stencilVals[j] - 1;
+ }
+ }
+ }
+ break;
+ case PIPE_STENCIL_OP_INCR_WRAP:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if (mask & (1 << j)) {
+ newstencil[j] = stencilVals[j] + 1;
+ }
+ }
+ break;
+ case PIPE_STENCIL_OP_DECR_WRAP:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if (mask & (1 << j)) {
+ newstencil[j] = stencilVals[j] - 1;
+ }
+ }
+ break;
+ case PIPE_STENCIL_OP_INVERT:
+ for (j = 0; j < QUAD_SIZE; j++) {
+ if (mask & (1 << j)) {
+ newstencil[j] = ~stencilVals[j];
+ }
+ }
+ break;
+ default:
+ assert(0);
+ }
+
+ /*
+ * update the stencil values
+ */
+ if (wrtMask != STENCIL_MAX) {
+ /* apply bit-wise stencil buffer writemask */
+ for (j = 0; j < QUAD_SIZE; j++) {
+ stencilVals[j] = (wrtMask & newstencil[j]) | (~wrtMask & stencilVals[j]);
+ }
+ }
+ else {
+ for (j = 0; j < QUAD_SIZE; j++) {
+ stencilVals[j] = newstencil[j];
+ }
+ }
+}
+
+
+/**
+ * Do stencil (and depth) testing. Stenciling depends on the outcome of
+ * depth testing.
+ */
+static void
+stencil_test_quad(struct quad_stage *qs, struct quad_header *quad)
+{
+ struct softpipe_context *softpipe = qs->softpipe;
+ struct softpipe_surface *s_surf = softpipe_surface(softpipe->framebuffer.sbuf);
+ GLuint func, zFailOp, zPassOp, failOp;
+ GLubyte ref, wrtMask, valMask;
+ GLubyte stencilVals[QUAD_SIZE];
+
+ /* choose front or back face function, operator, etc */
+ /* XXX we could do these initializations once per primitive */
+ if (softpipe->stencil.back_enabled && quad->facing) {
+ func = softpipe->stencil.back_func;
+ failOp = softpipe->stencil.back_fail_op;
+ zFailOp = softpipe->stencil.back_zfail_op;
+ zPassOp = softpipe->stencil.back_zpass_op;
+ ref = softpipe->stencil.ref_value[1];
+ wrtMask = softpipe->stencil.write_mask[1];
+ valMask = softpipe->stencil.value_mask[1];
+ }
+ else {
+ func = softpipe->stencil.front_func;
+ failOp = softpipe->stencil.front_fail_op;
+ zFailOp = softpipe->stencil.front_zfail_op;
+ zPassOp = softpipe->stencil.front_zpass_op;
+ ref = softpipe->stencil.ref_value[0];
+ wrtMask = softpipe->stencil.write_mask[0];
+ valMask = softpipe->stencil.value_mask[0];
+ }
+
+ assert(s_surf); /* shouldn't get here if there's no stencil buffer */
+ s_surf->read_quad_stencil(s_surf, quad->x0, quad->y0, stencilVals);
+
+ /* do the stencil test first */
+ {
+ GLbitfield passMask, failMask;
+ passMask = do_stencil_test(stencilVals, func, ref, valMask);
+ failMask = quad->mask & ~passMask;
+ quad->mask &= passMask;
+
+ if (failOp != PIPE_STENCIL_OP_KEEP) {
+ apply_stencil_op(stencilVals, failMask, failOp, ref, wrtMask);
+ }
+ }
+
+ if (quad->mask) {
+
+ /* now the pixels that passed the stencil test are depth tested */
+ if (softpipe->depth_test.enabled) {
+ const GLbitfield origMask = quad->mask;
+
+ sp_depth_test_quad(qs, quad); /* quad->mask is updated */
+
+ /* update stencil buffer values according to z pass/fail result */
+ if (zFailOp != PIPE_STENCIL_OP_KEEP) {
+ const GLbitfield failMask = origMask & ~quad->mask;
+ apply_stencil_op(stencilVals, failMask, zFailOp, ref, wrtMask);
+ }
+
+ if (zPassOp != PIPE_STENCIL_OP_KEEP) {
+ const GLbitfield passMask = origMask & quad->mask;
+ apply_stencil_op(stencilVals, passMask, zPassOp, ref, wrtMask);
+ }
+ }
+ else {
+ /* no depth test, apply Zpass operator to stencil buffer values */
+ apply_stencil_op(stencilVals, quad->mask, zPassOp, ref, wrtMask);
+ }
+
+ }
+
+ s_surf->write_quad_stencil(s_surf, quad->x0, quad->y0, stencilVals);
+
+ if (quad->mask)
+ qs->next->run(qs->next, quad);
+}
+
+
+
+
+struct quad_stage *sp_quad_stencil_test_stage( struct softpipe_context *softpipe )
+{
+ struct quad_stage *stage = CALLOC_STRUCT(quad_stage);
+
+ stage->softpipe = softpipe;
+ stage->run = stencil_test_quad;
+
+ return stage;
+}
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