nx_light_test.nx source

1// nx_light_test.nx -- smoke for V3 light/exposure primitives. 2 3import "syscalls.nx" 4import "nx_image.nx" 5import "nx_light.nx" 6 7func main() -> i64 { 8 // === Test 1: integer sqrt === 9 if nx_math_isqrt(0) != 0 { return 1 } 10 if nx_math_isqrt(100) != 10 { return 2 } 11 if nx_math_isqrt(16129) != 127 { return 3 } 12 13 // === Test 2: mean luminance on uniform image === 14 let img1: *Image = nx_image_alloc(16, 16, 1) 15 var y: i64 = 0 16 while y < 16 { 17 var x: i64 = 0 18 while x < 16 { 19 nx_image_set(img1, x, y, 0, 100) 20 x = x + 1 21 } 22 y = y + 1 23 } 24 if nx_light_mean_luminance(img1) != 100 { return 10 } 25 26 // === Test 3: stddev on uniform image = 0 === 27 if nx_light_stddev_luminance(img1, 100) != 0 { return 11 } 28 29 // === Test 4: min/max on uniform === 30 if nx_light_min(img1) != 100 { return 12 } 31 if nx_light_max(img1) != 100 { return 13 } 32 if nx_light_dynamic_range(img1) != 0 { return 14 } 33 34 // === Test 5: checkerboard 0/255 stats === 35 let img2: *Image = nx_image_alloc(16, 16, 1) 36 var y2: i64 = 0 37 while y2 < 16 { 38 var x2: i64 = 0 39 while x2 < 16 { 40 let par: i64 = (x2 + y2) - ((x2 + y2) / 2) * 2 41 var v: i64 = 0 42 if par == 1 { v = 255 } 43 nx_image_set(img2, x2, y2, 0, v) 44 x2 = x2 + 1 45 } 46 y2 = y2 + 1 47 } 48 // Mean = 127 (128 pixels at 255, 128 at 0, total 32640, /256 = 127.5 -> 127 int) 49 let m2: i64 = nx_light_mean_luminance(img2) 50 if m2 < 126 { return 20 } 51 if m2 > 128 { return 21 } 52 // Stddev ~= 127 (each pixel deviates by 127.5) 53 let s2: i64 = nx_light_stddev_luminance(img2, m2) 54 if s2 < 120 { return 22 } 55 if s2 > 130 { return 23 } 56 // Range = 255 57 if nx_light_dynamic_range(img2) != 255 { return 24 } 58 59 // === Test 6: underexposed fraction === 60 // Image is all dark (value 5). Underexposed below 10 = all pixels. 61 let img3: *Image = nx_image_alloc(16, 16, 1) 62 var y3: i64 = 0 63 while y3 < 16 { 64 var x3: i64 = 0 65 while x3 < 16 { 66 nx_image_set(img3, x3, y3, 0, 5) 67 x3 = x3 + 1 68 } 69 y3 = y3 + 1 70 } 71 let u3: i64 = nx_light_underexposed_frac(img3, 10) 72 if u3 != 1024 { return 30 } 73 74 // === Test 7: overexposed fraction === 75 let img4: *Image = nx_image_alloc(16, 16, 1) 76 var y4: i64 = 0 77 while y4 < 16 { 78 var x4: i64 = 0 79 while x4 < 16 { 80 nx_image_set(img4, x4, y4, 0, 250) 81 x4 = x4 + 1 82 } 83 y4 = y4 + 1 84 } 85 let o4: i64 = nx_light_overexposed_frac(img4, 245) 86 if o4 != 1024 { return 31 } 87 88 // === Test 8: direction classifier === 89 // Strong positive gx, zero gy -> East (0) 90 if nx_light_direction_classify(100, 0) != 0 { return 40 } 91 // Strong negative gx -> West (4) 92 if nx_light_direction_classify(-100, 0) != 4 { return 41 } 93 // Strong positive gy -> South (y-down) (2) 94 if nx_light_direction_classify(0, 100) != 2 { return 42 } 95 // Strong negative gy -> North (6) 96 if nx_light_direction_classify(0, -100) != 6 { return 43 } 97 // Both positive, equal -> SE (1) 98 if nx_light_direction_classify(50, 50) != 1 { return 44 } 99 // Negative x, positive y -> SW (3) 100 if nx_light_direction_classify(-50, 50) != 3 { return 45 } 101 // Both negative -> NW (5) 102 if nx_light_direction_classify(-50, -50) != 5 { return 46 } 103 // Positive x, negative y -> NE (7) 104 if nx_light_direction_classify(50, -50) != 7 { return 47 } 105 // Zero magnitude -> -1 106 if nx_light_direction_classify(0, 0) != -1 { return 48 } 107 108 // === Test 9: direction histogram on a vertical edge === 109 // Vertical edge (right=bright, left=dark) yields gx>0, gy=0. 110 // Most votes should be in bin 0 (East). 111 let edge: *Image = nx_image_alloc(16, 16, 1) 112 var yv: i64 = 0 113 while yv < 16 { 114 var xv: i64 = 0 115 while xv < 16 { 116 var v: i64 = 0 117 if xv >= 8 { v = 255 } 118 nx_image_set(edge, xv, yv, 0, v) 119 xv = xv + 1 120 } 121 yv = yv + 1 122 } 123 let gx: *ImageS64 = nx_image_sobel_x(edge) 124 let gy: *ImageS64 = nx_image_sobel_y(edge) 125 let hist: *i64 = (sys_mmap(8 * 8)) as *i64 126 nx_light_direction_hist(gx, gy, 100, hist) 127 // Bin 0 (East) should dominate 128 var dominant: i64 = 0 129 var best_v: i64 = hist[0] 130 var i: i64 = 1 131 while i < 8 { 132 if hist[i] > best_v { 133 best_v = hist[i] 134 dominant = i 135 } 136 i = i + 1 137 } 138 if dominant != 0 { return 50 } 139 140 return 0 141}