- switch (oper) {
- case GL_KEEP:
- /* do nothing */
- break;
- case GL_ZERO:
- if (invmask==0) {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- *sptr = 0;
- }
- }
- }
- else {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- *sptr = (GLstencil) (invmask & *sptr);
- }
- }
- }
- break;
- case GL_REPLACE:
- if (invmask==0) {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- *sptr = ref;
- }
- }
- }
- else {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- *sptr = (GLstencil) ((invmask & *sptr ) | (wrtmask & ref));
- }
- }
- }
- break;
- case GL_INCR:
- if (invmask==0) {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- if (*sptr < STENCIL_MAX) {
- *sptr = (GLstencil) (*sptr + 1);
- }
- }
- }
- }
- else {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- if (*sptr < STENCIL_MAX) {
- *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr+1)));
- }
- }
- }
- }
- break;
- case GL_DECR:
- if (invmask==0) {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- if (*sptr>0) {
- *sptr = (GLstencil) (*sptr - 1);
- }
- }
- }
- }
- else {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- if (*sptr>0) {
- *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr-1)));
- }
- }
- }
- }
- break;
- case GL_INCR_WRAP_EXT:
- if (invmask==0) {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- *sptr = (GLstencil) (*sptr + 1);
- }
- }
- }
- else {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr+1)));
- }
- }
- }
- break;
- case GL_DECR_WRAP_EXT:
- if (invmask==0) {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- *sptr = (GLstencil) (*sptr - 1);
- }
- }
- }
- else {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & (*sptr-1)));
- }
- }
- }
- break;
- case GL_INVERT:
- if (invmask==0) {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- *sptr = (GLstencil) (~*sptr);
- }
- }
- }
- else {
- for (i=0;i<n;i++) {
- if (mask[i]) {
- GLstencil *sptr = STENCIL_ADDRESS( x[i], y[i] );
- *sptr = (GLstencil) ((invmask & *sptr) | (wrtmask & ~*sptr));
- }
- }
- }
- break;
- default:
- gl_problem(ctx, "Bad stencilop in apply_stencil_op_to_pixels");