GLSL compile error "memory exhausted" -
i trying implement glsl fragment shader complex if-else decision tree. unfortunately shader compiler fails quite "syntax error - memory exhausted" error. there constraints code size or decision tree depth in glsl? suggestion how overcome issue?
bool block1(float p[16], float cb, float c_b) { if(p[6] > cb) if(p[7] > cb) if(p[8] > cb) return true; else if(p[15] > cb) return true; else return false; else if(p[7] < c_b) if(p[14] > cb) if(p[15] > cb) return true; else return false; else if(p[14] < c_b) if(p[8] < c_b) if(p[9] < c_b) if(p[10] < c_b) if(p[11] < c_b) if(p[12] < c_b) if(p[13] < c_b) if(p[15] < c_b) return true; else return false; // ';' : syntax error memory exhausted else return false; else return false; else return false; else return false; else return false; else return false; else return false; else if(p[14] > cb) if(p[15] > cb) return true; else return false; else return false; else if(p[6] < c_b) if(p[15] > cb) if(p[13] > cb) if(p[14] > cb) return true; else return false; else if(p[13] < c_b) if(p[7] < c_b) if(p[8] < c_b) if(p[9] < c_b) if(p[10] < c_b) if(p[11] < c_b) if(p[12] < c_b) if(p[14] < c_b) return true; else return false; else return false; else return false; else return false; else return false; else return false; else return false; else return false; else if(p[7] < c_b) if(p[8] < c_b) if(p[9] < c_b) if(p[10] < c_b) if(p[11] < c_b) if(p[12] < c_b) if(p[13] < c_b) if(p[14] < c_b) return true; else return false; else return false; else return false; else return false; else return false; else return false; else return false; else return false; else if(p[13] > cb) if(p[14] > cb) if(p[15] > cb) return true; else return false; else return false; else if(p[13] < c_b) if(p[7] < c_b) if(p[8] < c_b) if(p[9] < c_b) if(p[10] < c_b) if(p[11] < c_b) if(p[12] < c_b) if(p[14] < c_b) if(p[15] < c_b) return true; else return false; else return false; else return false; else return false; else return false; else return false; else return false; else return false; else return false; }
i'm going go out on limb here, know nothing shader languages.
1. use logic combinations (and, or)
however know general logic , lots of programming languages. chances big construct like:
if(p[8] < c_b) if(p[9] < c_b) if(p[10] < c_b) if(p[11] < c_b) if(p[12] < c_b) if(p[13] < c_b) if(p[15] < c_b) return true; else return false; // ';' : syntax error memory exhausted else return false; else return false; else return false; else return false; else return false; else return false; could trivially stated equivalently following (single) boolean expression:
return (p[8] < c_b) && (p[9] < c_b) && (p[10] < c_b) && (p[11] < c_b) && (p[12] < c_b) && (p[13] < c_b) && (p[15] < c_b); you might have use and instead of && depending on exact grammar of particular language.
2. eliminate redundancy
i noticed @ least 2 of 'subtrees' identical. more specifically, e.g. line #57 (formatting condensed convenience, here):
if(p[13] < c_b) if(p[7] < c_b) if(p[8] < c_b) if(p[9] < c_b) if(p[10] < c_b) if(p[11] < c_b) if(p[12] < c_b) if(p[14] < c_b) return true; else return false; else return false; else return false; else return false; else return false; else return false; else return false; else return false; is identical line #83
if(p[7] < c_b) if(p[8] < c_b) if(p[9] < c_b) if(p[10] < c_b) if(p[11] < c_b) if(p[12] < c_b) if(p[13] < c_b) if(p[14] < c_b) return true; else return false; else return false; else return false; else return false; else return false; else return false; else return false; else just (p[13] < c_b) condition moved nearer end. highly combine branches in occurs.
instead of manually doing (painstaking) process, suggest making truth table (just map out possible inputs) , deducing single boolean expression generate result value that.
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