A slightly different approach (sorta seems to work for me).
The idea is to use shaders to rescale the heightmap into a (0,1) range
Code: Select all
local heightmapScaleShader = [[
uniform sampler2D heightmapTex;
uniform float maxPos, maxNeg;
void main() {
gl_FragColor = texture2D(heightmapTex, gl_TexCoord[0].st);
gl_FragColor.rgb = (gl_FragColor.rgb - maxNeg) / (maxPos - maxNeg);
}
]]
local shader = gl.CreateShader({ fragment = heightmapScaleShader, uniformInt = {heightmapTexID = 0 }})
local errors = gl.GetShaderLog(shader)
if errors ~= "" then
Spring.Echo(errors)
end
local heightmapTexID = gl.GetUniformLocation(shader, "heightmapTex")
local maxPosID = gl.GetUniformLocation(shader, "maxPos")
local maxNegID = gl.GetUniformLocation(shader, "maxNeg")
-- heightmap
local heightmapPath = self.path .. "/heightmap.png"
Spring.Echo("Saving the heightmap to " .. heightmapPath .. "...")
if VFS.FileExists(heightmapPath, VFS.RAW) then
Spring.Echo("removing the existing heightmap")
os.remove(heightmapPath)
end
local texInfo = gl.TextureInfo("$heightmap")
local heightmapTexture = gl.CreateTexture(texInfo.xsize, texInfo.ysize, {
border = false,
min_filter = GL.NEAREST,
mag_filter = GL.NEAREST,
wrap_s = GL.CLAMP_TO_EDGE,
wrap_t = GL.CLAMP_TO_EDGE,
fbo = true,
})
-- not used, seem incorrect
local minHeight, maxHeight = Spring.GetGroundExtremes()
Spring.Echo(maxHeight, minHeight)
local maxH, minH = -math.huge, math.huge
for x = 0, Game.mapSizeX, Game.squareSize do
for z = 0, Game.mapSizeZ, Game.squareSize do
local groundHeight = Spring.GetGroundHeight(x, z)
if groundHeight > maxH then
maxH = groundHeight
end
if groundHeight < minH then
minH = groundHeight
end
end
end
Spring.Echo(minH, maxH)
gl.UseShader(shader)
gl.Uniform(maxPosID, maxH)
gl.Uniform(maxNegID, minH)
gl.Texture(0, "$heightmap")
gl.RenderToTexture(heightmapTexture,
function()
gl.TexRect(-1,-1, 1, 1)
end)
gl.Texture(0, false)
gl.UseShader(0)
gl.RenderToTexture(heightmapTexture, gl.SaveImage, 0, 0, texInfo.xsize, texInfo.ysize, heightmapPath)
gl.DeleteTexture(heightmapTexture)
Resulting heightmap attached (looks correctish)
