String DxBuilder::buildStructs(const ASTEffect& effect, const ASTFunction& function)
{
typedef std::vector<const ASTStruct*> Structs;
Structs structs;
if ( function.mpType->isStruct() )
{
const ASTStruct& aststruct = function.mpType->getStruct();
structs.push_back(&aststruct);
}
for ( std::size_t index = 0; index < function.mArguments.size(); ++index )
{
const ASTFunctionArgument* parg = function.mArguments[index];
if ( parg->mpType->isStruct() )
{
int s = 0;
const ASTStruct& aststruct = parg->mpType->getStruct();
for ( ; s < structs.size(); ++s )
{
if ( structs[s] == &aststruct )
{
break;
}
}
if ( s == structs.size() )
{
structs.push_back(&aststruct);
}
}
}
String code;
for ( std::size_t index = 0; index < structs.size(); ++index )
{
const ASTStruct* pstruct = structs[index];
code += buildStruct(*pstruct);
}
return code;
}
void Heightfield::fillProperties(ParsedBlock& pb)
{
Bitmap* bmp = NULL;
if (!pb.getBitmapFileProp("file", &bmp, filename)) pb.requiredProp("file");
W = bmp->getWidth();
H = bmp->getHeight();
blur = 0;
pb.getDoubleProp("blur", &blur);
heights = new float[W * H];
float minY = LARGE_FLOAT, maxY = -LARGE_FLOAT;
// do we have blur? if no, just fetch the source image and store it:
if (blur <= 0) {
for (int y = 0; y < H; y++)
for (int x = 0; x < W; x++) {
float h = bmp->getPixel(x, y).intensity();
heights[y * W + x] = h;
minY = min(minY, h);
maxY = max(maxY, h);
}
} else {
// We have blur...
// 1) convert image to greyscale (if not already):
for (int y = 0; y < H; y++) {
for (int x = 0; x < W; x++) {
float f = bmp->getPixel(x, y).intensity();
bmp->setPixel(x, y, Color(f, f, f));
}
}
// 2) calculate the gaussian coefficients, see http://en.wikipedia.org/wiki/Gaussian_blur
static float gauss[128][128];
int R = min(128, nearestInt(float(3 * blur)));
for (int y = 0; y < R; y++)
for (int x = 0; x < R; x++)
gauss[y][x] = float(exp(-(sqr(x) + sqr(y))/(2 * sqr(blur))) / (2 * PI * sqr(blur)));
// 3) apply gaussian blur with the specified number of blur units:
// (this is potentially slow for large blur radii)
for (int y = 0; y < H; y++) {
for (int x = 0; x < W; x++) {
float sum = 0;
for (int dy = -R + 1; dy < R; dy++)
for (int dx = -R + 1; dx < R; dx++)
sum += gauss[abs(dy)][abs(dx)] * bmp->getPixel(x + dx, y + dy).r;
heights[y * W + x] = sum;
minY = min(minY, sum);
maxY = max(maxY, sum);
}
}
}
// set the bounding box. minY and maxY are the bbox extents along Y and are calculated
// from the heights[] array.
bbox.vmin = Vector(0, minY, 0);
bbox.vmax = Vector(W, maxY, H);
// calculate the maxH array. maxH(x, y) = max(H(x, y), H(x + 1, y), H(x, y + 1), H(x + 1, y+1))
maxH = new float[W*H];
for (int y = 0; y < H; y++)
for (int x = 0; x < W; x++) {
float& maxH = this->maxH[y * W + x];
maxH = heights[y * W + x];
if (x < W - 1) maxH = max(maxH, heights[y * W + x + 1]);
if (y < H - 1) {
maxH = max(maxH, heights[(y + 1) * W + x]);
if (x < W - 1)
maxH = max(maxH, heights[(y + 1) * W + x + 1]);
}
}
// precalculate the normals at each integer point. We create normals by doing two forward differences
// on the height along x and y at each point and using the cross product of these differences to
// obtain the normal vector
normals = new Vector[W * H];
for (int y = 0; y < H; y++)
for (int x = 0; x < W; x++) {
float h0 = heights[y * W + x];
float hdx = heights[y * W + min(W - 1, x + 1)];
float hdy = heights[min(H - 1, y + 1) * W + x];
Vector vdx = Vector(1, hdx - h0, 0); // forward difference along X
Vector vdy = Vector(0, hdy - h0, 1); // forward difference along Z
Vector norm = vdy ^ vdx;
norm.normalize();
normals[y * W + x] = norm;
}
useOptimization = false;
pb.getBoolProp("useOptimization", &useOptimization);
if (!disableAcceleratedStructures && useOptimization) {
Uint32 clk = SDL_GetTicks();
buildStruct();
clk = SDL_GetTicks() - clk;
printf("Heightfield acceleration struct built in %.3lfs\n", clk / 1000.0);
}
}
