src/gallium/drivers/llvmpipe/lp_bld_interp.h

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  27
  28 /**
  29  * @file
  30  * Position and shader input interpolation.
  31  *
  32  * Special attention is given to the interpolation of side by side quads.
  33  * Multiplications are made only for the first quad. Interpolation of
  34  * inputs for posterior quads are done exclusively with additions, and
  35  * perspective divide if necessary.
  36  *
  37  * @author Jose Fonseca <jfonseca@vmware.com>
  38  */
  39
  40 #ifndef LP_BLD_INTERP_H
  41 #define LP_BLD_INTERP_H
  42
  43
  44 #include "gallivm/lp_bld.h"
  45 #include "gallivm/lp_bld_type.h"
  46
  47 #include "tgsi/tgsi_exec.h"
  48
  49 /**
  50  * Describes how to compute the interpolation coefficients (a0, dadx, dady)
  51  * from the vertices passed into our triangle/line/point functions by the
  52  * draw module.
  53  *
  54  * Vertices are treated as an array of float[4] values, indexed by
  55  * src_index.
  56  *
  57  * LP_INTERP_COLOR is translated to either LP_INTERP_CONSTANT or
  58  * PERSPECTIVE depending on flatshade state.
  59  */
  60 enum lp_interp {
  61    LP_INTERP_CONSTANT,
  62    LP_INTERP_COLOR,
  63    LP_INTERP_LINEAR,
  64    LP_INTERP_PERSPECTIVE,
  65    LP_INTERP_POSITION,
  66    LP_INTERP_FACING
  67 };
  68
  69 struct lp_shader_input {
  70    uint interp:4;       /* enum lp_interp */
  71    uint usage_mask:4;   /* bitmask of TGSI_WRITEMASK_x flags */
  72    uint src_index:8;    /* where to find values in incoming vertices */
  73    uint cyl_wrap:4;     /* TGSI_CYLINDRICAL_WRAP_x flags */
  74    uint padding:12;
  75 };
  76
  77
  78 struct lp_build_interp_soa_context
  79 {
  80    /* TGSI_QUAD_SIZE x float */
  81    struct lp_build_context coeff_bld;
  82    struct lp_build_context setup_bld;
  83
  84    unsigned num_attribs;
  85    unsigned mask[1 + PIPE_MAX_SHADER_INPUTS]; /**< TGSI_WRITE_MASK_x */
  86    enum lp_interp interp[1 + PIPE_MAX_SHADER_INPUTS];
  87    boolean simple_interp;
  88    boolean dynamic_offsets;
  89
  90    LLVMValueRef x;
  91    LLVMValueRef y;
  92
  93    LLVMValueRef a[1 + PIPE_MAX_SHADER_INPUTS][TGSI_NUM_CHANNELS];
  94    LLVMValueRef dadq[1 + PIPE_MAX_SHADER_INPUTS][TGSI_NUM_CHANNELS];
  95    LLVMValueRef a0aos[1 + PIPE_MAX_SHADER_INPUTS];
  96    LLVMValueRef dadxaos[1 + PIPE_MAX_SHADER_INPUTS];
  97    LLVMValueRef dadyaos[1 + PIPE_MAX_SHADER_INPUTS];
  98
  99    LLVMValueRef oow;
 100
 101    LLVMValueRef attribs[1 + PIPE_MAX_SHADER_INPUTS][TGSI_NUM_CHANNELS];
 102
 103    LLVMValueRef xoffset_store;
 104    LLVMValueRef yoffset_store;
 105
 106    /*
 107     * Convenience pointers. Callers may access this one.
 108     */
 109    const LLVMValueRef *pos;
 110    const LLVMValueRef (*inputs)[TGSI_NUM_CHANNELS];
 111 };
 112
 113
 114 void
 115 lp_build_interp_soa_init(struct lp_build_interp_soa_context *bld,
 116                          struct gallivm_state *gallivm,
 117                          unsigned num_inputs,
 118                          const struct lp_shader_input *inputs,
 119                          LLVMBuilderRef builder,
 120                          struct lp_type type,
 121                          boolean dynamic_offsets,
 122                          LLVMValueRef a0_ptr,
 123                          LLVMValueRef dadx_ptr,
 124                          LLVMValueRef dady_ptr,
 125                          LLVMValueRef x,
 126                          LLVMValueRef y);
 127
 128 void
 129 lp_build_interp_soa_update_inputs(struct lp_build_interp_soa_context *bld,
 130                                   struct gallivm_state *gallivm,
 131                                   int quad_start_index);
 132
 133 void
 134 lp_build_interp_soa_update_pos(struct lp_build_interp_soa_context *bld,
 135                                struct gallivm_state *gallivm,
 136                                int quad__start_index);
 137
 138 void
 139 lp_build_interp_soa_update_inputs_dyn(struct lp_build_interp_soa_context *bld,
 140                                       struct gallivm_state *gallivm,
 141                                       LLVMValueRef quad_start_index);
 142
 143 void
 144 lp_build_interp_soa_update_pos_dyn(struct lp_build_interp_soa_context *bld,
 145                                    struct gallivm_state *gallivm,
 146                                    LLVMValueRef quad_start_index);
 147
 148 #endif /* LP_BLD_INTERP_H */