diff options
author | Marek Olšák <maraeo@gmail.com> | 2010-08-10 14:21:05 +0200 |
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committer | Marek Olšák <maraeo@gmail.com> | 2010-08-11 04:48:56 +0200 |
commit | 683ef52e19576f6e1263bc7d25fc9475c519eade (patch) | |
tree | 515c341dfb256f80a63df288088ddfade910a8ba /src/mesa/drivers/dri | |
parent | cc732bf894f58fd1533709ac60d3af4c80bd01b0 (diff) |
r300g: implement gl_FrontFacing
Diffstat (limited to 'src/mesa/drivers/dri')
-rw-r--r-- | src/mesa/drivers/dri/r300/compiler/radeon_compiler.c | 43 | ||||
-rw-r--r-- | src/mesa/drivers/dri/r300/compiler/radeon_compiler.h | 1 |
2 files changed, 44 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_compiler.c b/src/mesa/drivers/dri/r300/compiler/radeon_compiler.c index 1c8ba864a4..935dc9b0a8 100644 --- a/src/mesa/drivers/dri/r300/compiler/radeon_compiler.c +++ b/src/mesa/drivers/dri/r300/compiler/radeon_compiler.c @@ -307,3 +307,46 @@ void rc_transform_fragment_wpos(struct radeon_compiler * c, unsigned wpos, unsig } } + +/** + * The FACE input in hardware contains 1 if it's a back face, 0 otherwise. + * Gallium and OpenGL define it the other way around. + * + * So let's just negate FACE at the beginning of the shader and rewrite the rest + * of the shader to read from the newly allocated temporary. + */ +void rc_transform_fragment_face(struct radeon_compiler *c, unsigned face) +{ + unsigned tempregi = rc_find_free_temporary(c); + struct rc_instruction *inst_add; + struct rc_instruction *inst; + + /* perspective divide */ + inst_add = rc_insert_new_instruction(c, &c->Program.Instructions); + inst_add->U.I.Opcode = RC_OPCODE_ADD; + + inst_add->U.I.DstReg.File = RC_FILE_TEMPORARY; + inst_add->U.I.DstReg.Index = tempregi; + inst_add->U.I.DstReg.WriteMask = RC_MASK_X; + + inst_add->U.I.SrcReg[0].File = RC_FILE_NONE; + inst_add->U.I.SrcReg[0].Swizzle = RC_SWIZZLE_1111; + + inst_add->U.I.SrcReg[1].File = RC_FILE_INPUT; + inst_add->U.I.SrcReg[1].Index = face; + inst_add->U.I.SrcReg[1].Swizzle = RC_SWIZZLE_XXXX; + inst_add->U.I.SrcReg[1].Negate = RC_MASK_XYZW; + + for (inst = inst_add->Next; inst != &c->Program.Instructions; inst = inst->Next) { + const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->U.I.Opcode); + unsigned i; + + for(i = 0; i < opcode->NumSrcRegs; i++) { + if (inst->U.I.SrcReg[i].File == RC_FILE_INPUT && + inst->U.I.SrcReg[i].Index == face) { + inst->U.I.SrcReg[i].File = RC_FILE_TEMPORARY; + inst->U.I.SrcReg[i].Index = tempregi; + } + } + } +} diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_compiler.h b/src/mesa/drivers/dri/r300/compiler/radeon_compiler.h index e15291dd19..7c42eb3ae5 100644 --- a/src/mesa/drivers/dri/r300/compiler/radeon_compiler.h +++ b/src/mesa/drivers/dri/r300/compiler/radeon_compiler.h @@ -81,6 +81,7 @@ void rc_move_output(struct radeon_compiler * c, unsigned output, unsigned new_ou void rc_copy_output(struct radeon_compiler * c, unsigned output, unsigned dup_output); void rc_transform_fragment_wpos(struct radeon_compiler * c, unsigned wpos, unsigned new_input, int full_vtransform); +void rc_transform_fragment_face(struct radeon_compiler *c, unsigned face); struct r300_fragment_program_compiler { struct radeon_compiler Base; |