2010-12-29
This short demo provides a function to save a VERGE image reference as a .BMP, and provides a brief example.
This is a lua-fication of http://verge-rpg.com/general/tileset-maker/
[code]
function WriteFileBitmap24(out_image_handle, filename)
img_x = v3.ImageWidth(out_image_handle)
img_y = v3.ImageHeight(out_image_handle)
if (img_x * img_y) == 0 then
return 0 -- Return on bad image
end
if (img_x * 3 % 4) then
img_xtra = 4 - (img_x * 3 % 4) -- Padding needed
else
img_xtra = 0 -- No padding needed
end
img_size = ((3 * img_x) + img_xtra) * img_y -- Size of image data in bytes
out_file = v3.FileOpen(filename .. '.bmp', v3.FILE_WRITE)
if out_file <= 0 then
return 0 -- Return on bad path or unopenable file
end
v3.FileWriteWord(out_file, 19778) -- bfType - Header of 'BM'
v3.FileWriteQuad(out_file, 54 + img_size) -- bfSize - File size
v3.FileWriteQuad(out_file, 0) -- bfReserved1, bfReserved2 - Two reserved words
v3.FileWriteQuad(out_file, 54) -- bfOffBits - Offset to image data
v3.FileWriteQuad(out_file, 40) -- biSize - Size of (windows) bitmap info structure
v3.FileWriteQuad(out_file, img_x) -- biWidth - Image width
v3.FileWriteQuad(out_file, img_y) -- biHeight - Image height
v3.FileWriteWord(out_file, 1) -- biPlanes - Err... one
v3.FileWriteWord(out_file, 24) -- biBitCount - Bits per pixel
v3.FileWriteQuad(out_file, 0) -- biCompression - No compression
v3.FileWriteQuad(out_file, img_size) -- biSizeImage - Size of bitmap data
v3.FileWriteQuad(out_file, 0) -- biXPelsPerMeter
v3.FileWriteQuad(out_file, 0) -- biYPelsPerMeter
-- X/YPelsPerMeter specifies the horizontal/vertical resolution,
-- in pixels per meter, of the target device for the bitmap.
-- An application can use this value to select a bitmap from a resource
-- group that best matches the characteristics of the current device.
v3.FileWriteQuad(out_file, 0) -- biClrUsed - Not palletted data
v3.FileWriteQuad(out_file, 0) -- biClrImportant - All colours important
for yi = (img_y - 1), 0, -1 do --Move from bottom of image data up
for xi = 0, (img_x-1), 1 do -- Write row of pixels
out_pixel = v3.GetPixel(xi, yi, out_image_handle)
v3.FileWriteByte(out_file, v3.GetB(out_pixel))
v3.FileWriteByte(out_file, v3.GetG(out_pixel))
v3.FileWriteByte(out_file, v3.GetR(out_pixel))
end
-- for xi = img_xtra, 1, -1 do -- Pad to quad width
-- v3.FileWriteByte(out_file, 0);
-- end
end
v3.FileClose(out_file);
return img_size;
end
[/code]
