#include <pixman.h>

/*
 * The basic idea:
 *
 * A /program/ is a list of instructions that
 *
 * - takes a number of *source* images (numbered from 0 to n)
 * - takes one destination image
 * - takes a clip region parameter
 * 
 * When executed, for each pixel in the destination image,
 * the instructions are interpreted and the result is written
 * back.
 *
 * Do we talk about /pixels/ here? Yes, probably, though there
 * is nothing stopping people from treating an image as if it were
 * an a8.
 *
 */

typedef struct psl_program_t psl_program_t;
typedef struct psl_var_t psl_var_t;
typedef struct psl_instruction_t psl_instruction_t;
typedef struct instruction_list_t psl_statement_t;

psl_program_t *    psl_program_create  (psl_statement_t   *statement);
psl_var_t *	   psl_imm_un8         (int value);
psl_var_t *	   psl_imm_sp	       (float f);
psl_var_t *	   psl_var	       (const char *name);
psl_instruction_t *psl_tex             (psl_var_t	  *dest,
					psl_var_t         *img,
					psl_var_t         *u,
					psl_var_t         *v);
psl_instruction_t *psl_add	       (psl_var_t         *dest,
					psl_var_t	  *src1,
					psl_var_t	  *src2);
psl_instruction_t *psl_mad	       (psl_var_t	  *dest,
					psl_var_t	  *src1,
					psl_var_t	  *src2,
					psl_var_t	  *src3);
psl_instruction_t *psl_cmp_lt	       (psl_var_t	  *dest,
					psl_var_t	  *src1,
					psl_var_t	  *src2);
psl_instruction_t *psl_label	       (const char        *name);
psl_statement_t *  psl_asm             (psl_instruction_t *instruction,
					...);
void               psl_program_run     (psl_program_t      *program,
					pixman_region32_t  *clip,
					pixman_image_t     *destination,
					pixman_image_t    **sources);
void               psl_program_destroy (psl_program_t     *program);