tga_encoder/examples.lua

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dofile("init.lua")
-- encode a bitmap
local _ = { 0, 0, 0 }
local R = { 255, 127, 127 }
local pixels = {
{ _, _, _, _, _, _, _ },
{ _, _, _, R, _, _, _ },
{ _, _, R, R, R, _, _ },
{ _, R, R, R, R, R, _ },
{ _, R, R, R, R, R, _ },
{ _, _, R, _, R, _, _ },
{ _, _, _, _, _, _, _ },
}
tga_encoder.image(pixels):save("bitmap_small.tga")
-- change a single pixel, then rescale the bitmap
local pixels_orig = pixels
pixels_orig[4][4] = { 255, 255, 255 }
local pixels = {}
for x = 1,56,1 do
local x_orig = math.ceil(x/8)
for z = 1,56,1 do
local z_orig = math.ceil(z/8)
local color = pixels_orig[z_orig][x_orig]
pixels[z] = pixels[z] or {}
pixels[z][x] = color
end
end
tga_encoder.image(pixels):save("bitmap_large.tga")
-- note that the uncompressed grayscale TGA file written in this
-- example is 80 bytes but an optimized PNG file is 81 bytes …
local pixels = {}
for x = 1,6,1 do -- left to right
for z = 1,6,1 do -- bottom to top
local color = { math.min(x * z * 4 - 1, 255) }
pixels[z] = pixels[z] or {}
pixels[z][x] = color
end
end
tga_encoder.image(pixels, {colors="BW", pixel_depth=8}):save("gradients_8bpp.tga")
local pixels = {}
for x = 1,16,1 do -- left to right
for z = 1,16,1 do -- bottom to top
local r = math.min(x * 32 - 1, 255)
local g = math.min(z * 32 - 1, 255)
local b = 0
-- blue rectangle in top right corner
if x > 8 and z > 8 then
r = 0
g = 0
b = math.min(z * 16 - 1, 255)
end
local color = { r, g, b }
pixels[z] = pixels[z] or {}
pixels[z][x] = color
end
end
tga_encoder.image(pixels, {colors="RGB", pixel_depth=16}):save("gradients_16bpp.tga")
tga_encoder.image(pixels, {colors="RGB", pixel_depth=24}):save("gradients_24bpp.tga")
local pixels = {}
for x = 1,512,1 do -- left to right
for z = 1,512,1 do -- bottom to top
local oz = (z - 256) / 256 + 0.75
local ox = (x - 256) / 256
local px, pz, i = 0, 0, 0
while (px * px) + (pz * pz) <= 4 and i < 128 do
px = (px * px) - (pz * pz) + oz
pz = (2 * px * pz) + ox
i = i + 1
end
local color = {
math.max(0, math.min(255, math.floor(px * 64))),
math.max(0, math.min(255, math.floor(pz * 64))),
math.max(0, math.min(255, math.floor(i))),
}
pixels[z] = pixels[z] or {}
pixels[z][x] = color
end
end
tga_encoder.image(pixels, {colors="RGB", pixel_depth=24}):save("fractal_24bpp.tga")