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 location:2;     /* TGSI_INTERPOLOATE_LOC_* */
  75    uint padding:10;
  76 };
  77
  78
  79 struct lp_build_interp_soa_context
  80 {
  81    /* TGSI_QUAD_SIZE x float */
  82    struct lp_build_context coeff_bld;
  83    struct lp_build_context setup_bld;
  84
  85    unsigned num_attribs;
  86    unsigned mask[1 + PIPE_MAX_SHADER_INPUTS]; /**< TGSI_WRITE_MASK_x */
  87    enum lp_interp interp[1 + PIPE_MAX_SHADER_INPUTS];
  88    unsigned interp_loc[1 + PIPE_MAX_SHADER_INPUTS];
  89    boolean simple_interp;
  90    boolean depth_clamp;
  91
  92    double pos_offset;
  93    unsigned coverage_samples;
  94    LLVMValueRef num_loop;
  95    LLVMValueRef sample_pos_array;
  96
  97    LLVMValueRef x;
  98    LLVMValueRef y;
  99
 100    LLVMValueRef a[1 + PIPE_MAX_SHADER_INPUTS][TGSI_NUM_CHANNELS];
 101    LLVMValueRef dadq[1 + PIPE_MAX_SHADER_INPUTS][TGSI_NUM_CHANNELS];
 102    LLVMValueRef a0aos[1 + PIPE_MAX_SHADER_INPUTS];
 103    LLVMValueRef dadxaos[1 + PIPE_MAX_SHADER_INPUTS];
 104    LLVMValueRef dadyaos[1 + PIPE_MAX_SHADER_INPUTS];
 105
 106    LLVMValueRef attribs[1 + PIPE_MAX_SHADER_INPUTS][TGSI_NUM_CHANNELS];
 107
 108    LLVMValueRef xoffset_store;
 109    LLVMValueRef yoffset_store;
 110
 111    /*
 112     * Convenience pointers. Callers may access this one.
 113     */
 114    const LLVMValueRef *pos;
 115    const LLVMValueRef (*inputs)[TGSI_NUM_CHANNELS];
 116 };
 117
 118
 119 void
 120 lp_build_interp_soa_init(struct lp_build_interp_soa_context *bld,
 121                          struct gallivm_state *gallivm,
 122                          unsigned num_inputs,
 123                          const struct lp_shader_input *inputs,
 124                          boolean pixel_center_integer,
 125                          unsigned coverage_samples,
 126                          LLVMValueRef sample_pos_array,
 127                          LLVMValueRef num_loop,
 128                          boolean depth_clamp,
 129                          LLVMBuilderRef builder,
 130                          struct lp_type type,
 131                          LLVMValueRef a0_ptr,
 132                          LLVMValueRef dadx_ptr,
 133                          LLVMValueRef dady_ptr,
 134                          LLVMValueRef x,
 135                          LLVMValueRef y);
 136
 137 void
 138 lp_build_interp_soa_update_inputs_dyn(struct lp_build_interp_soa_context *bld,
 139                                       struct gallivm_state *gallivm,
 140                                       LLVMValueRef quad_start_index,
 141                                       LLVMValueRef mask_store,
 142                                       LLVMValueRef sample_id);
 143
 144 void
 145 lp_build_interp_soa_update_pos_dyn(struct lp_build_interp_soa_context *bld,
 146                                    struct gallivm_state *gallivm,
 147                                    LLVMValueRef quad_start_index,
 148                                    LLVMValueRef sample_id);
 149
 150 #endif /* LP_BLD_INTERP_H */