1
0
Fork 0
VoxeLibre/mods/CORE/tga_encoder/examples.lua

182 lines
5.2 KiB
Lua
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

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")
-- test that image can be encoded
local bitmap_small_0 = tga_encoder.image(pixels)
bitmap_small_0:encode()
assert(191 == #bitmap_small_0.data)
-- test that imbage can be encoded with parameters
local bitmap_small_1 = tga_encoder.image(pixels)
bitmap_small_1:encode(
{
colormap = {},
color_format = "B8G8R8",
compression = "RAW",
}
)
assert(191 == #bitmap_small_1.data)
-- 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):save("gradient_8bpp_raw.tga", {color_format="Y8", compression="RAW"})
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
local gradients = tga_encoder.image(pixels)
gradients:save("gradients_8bpp_raw.tga", {color_format="Y8", compression="RAW"})
gradients:save("gradients_16bpp_raw.tga", {color_format="A1R5G5B5", compression="RAW"})
gradients:save("gradients_16bpp_rle.tga", {color_format="A1R5G5B5", compression="RLE"})
gradients:save("gradients_24bpp_raw.tga", {color_format="B8G8R8", compression="RAW"})
gradients:save("gradients_24bpp_rle.tga", {color_format="B8G8R8", compression="RLE"})
for x = 1,16,1 do -- left to right
for z = 1,16,1 do -- bottom to top
local color = pixels[z][x]
color[#color+1] = ((x * x) + (z * z)) % 256
pixels[z][x] = color
end
end
gradients:save("gradients_32bpp_raw.tga", {color_format="B8G8R8A8", compression="RAW"})
-- the RLE-compressed file is larger than just dumping pixels because
-- the gradients in this picture can not be compressed well using RLE
gradients:save("gradients_32bpp_rle.tga", {color_format="B8G8R8A8", compression="RLE"})
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):save("fractal_8bpp.tga", {color_format="Y8"})
tga_encoder.image(pixels):save("fractal_16bpp.tga", {color_format="A1R5G5B5"})
tga_encoder.image(pixels):save("fractal_24bpp.tga", {color_format="B8G8R8"})
-- encode a colormapped bitmap
local K = { 0 }
local B = { 1 }
local R = { 2 }
local G = { 3 }
local W = { 4 }
local colormap = {
{ 1, 2, 3 }, -- K
{ 0, 0, 255 }, -- B
{ 255, 0, 0 }, -- R
{ 0, 255, 0 }, -- G
{ 253, 254, 255 }, -- W
}
local pixels = {
{ W, K, W, K, W, K, W },
{ R, G, B, R, G, B, K },
{ K, W, K, W, K, W, K },
{ G, B, R, G, B, R, W },
{ W, W, W, K, K, K, W },
{ B, R, G, B, R, G, K },
{ B, R, G, B, R, G, W },
}
-- note that the uncompressed colormapped TGA file written in this
-- example is 108 bytes but an optimized PNG file is 121 bytes …
tga_encoder.image(pixels):save("colormapped_B8G8R8.tga", {colormap=colormap})
-- encoding as A1R5G5B5 saves 1 byte per palette entry → 103 bytes
tga_encoder.image(pixels):save("colormapped_A1R5G5B5.tga", {colormap=colormap, color_format="A1R5G5B5"})
-- encode a colormapped bitmap with transparency
local _ = { 0 }
local K = { 1 }
local W = { 2 }
local colormap = {
{ 0, 0, 0, 0 },
{ 0, 0, 0, 255 },
{ 255, 255, 255, 255 },
}
local pixels = {
{ _, K, K, K, K, K, _ },
{ _, K, W, W, W, K, _ },
{ K, K, W, W, W, K, K },
{ K, W, W, W, W, W, K },
{ _, K, W, W, W, K, _ },
{ _, _, K, W, K, _, _ },
{ _, _, _, K, _, _, _ },
}
tga_encoder.image(pixels):save("colormapped_B8G8R8A8.tga", {colormap=colormap})
-- encoding a colormapped image with illegal colormap indexes should error out
local colormap = {
{ 0, 0, 0, 0 },
{ 0, 0, 0, 255 },
}
local status, message = pcall(
function ()
tga_encoder.image(pixels):encode({colormap=colormap})
end
)
assert(
false == status and
"init.lua:36: colormap index 2 not in colormap of size 2" == message
)