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Improves readability in BaseHeightMapRenderObjClass::Get_Height_Map_H…
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…eight (#917)
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@bobtista
bobtista authored Feb 10, 2024
1 parent 7eb9ef8 commit cfa005f
Showing 1 changed file with 74 additions and 63 deletions.
137 changes: 74 additions & 63 deletions src/platform/w3dengine/client/baseheightmap.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -969,89 +969,100 @@ void BaseHeightMapRenderObjClass::Do_The_Light(VertexFormatXYZDUV2 *vb,

float BaseHeightMapRenderObjClass::Get_Height_Map_Height(float x, float y, Coord3D *pos) const
{
WorldHeightMap *map;
WorldHeightMap *height_map;

// Check if terrain visual is available, otherwise use default map
if (g_theTerrainVisual != nullptr) {
map = g_theTerrainVisual->Get_Logic_Height_Map();
height_map = g_theTerrainVisual->Get_Logic_Height_Map();
} else {
map = m_map;
height_map = m_map;
}

if (map != nullptr) {
float f1 = x * 0.1f;
float f2 = y * 0.1f;
float f3 = GameMath::Fast_Float_Floor(f1);
float f4 = GameMath::Fast_Float_Floor(f2);
float f5 = f1 - f3;
float f6 = f2 - f4;
int i1 = map->Border_Size() + GameMath::Lrintf(f3);
int i2 = map->Border_Size() + GameMath::Lrintf(f4);
int x_extent = map->Get_X_Extent();

if (i1 <= x_extent - 3 && i2 <= map->Get_Y_Extent() - 3 && i2 >= 1 && i1 >= 1) {
unsigned char *data = map->Get_Data_Ptr();
int i3 = x_extent * i2 + i1;
float f7 = data[i3];
float f8 = data[x_extent + 1 + i3];
float f9;

if (f6 <= f5) {
float f10 = data[i3 + 1];
f9 = ((f8 - f10) * f6 + f10 + (1.0f - f5) * (f7 - f10)) * HEIGHTMAP_SCALE;
if (height_map != nullptr) {
float scaled_x = x * 0.1f;
float scaled_y = y * 0.1f;
float floor_x = GameMath::Fast_Float_Floor(scaled_x);
float floor_y = GameMath::Fast_Float_Floor(scaled_y);
float fract_x = scaled_x - floor_x;
float fract_y = scaled_y - floor_y;
int index_x = height_map->Border_Size() + GameMath::Lrintf(floor_x);
int index_y = height_map->Border_Size() + GameMath::Lrintf(floor_y);
int map_width = height_map->Get_X_Extent();

// Check if the indices are within valid bounds
if (index_x <= map_width - 3 && index_y <= height_map->Get_Y_Extent() - 3 && index_y >= 1 && index_x >= 1) {
unsigned char *height_data = height_map->Get_Data_Ptr();
int current_point_index = map_width * index_y + index_x;
float current_point_height = height_data[current_point_index];
float top_right_neighbor_height = height_data[map_width + 1 + current_point_index];
float interpolated_height;

// Calculate the height based on interpolation
// If fractional y is less than or equal to fractional x, our point is in the top right triangle of the cell
if (fract_y <= fract_x) {
float right_neighbor_height = height_data[current_point_index + 1];
interpolated_height = ((top_right_neighbor_height - right_neighbor_height) * fract_y + right_neighbor_height
+ (1.0f - fract_x) * (current_point_height - right_neighbor_height))
* HEIGHTMAP_SCALE;
} else {
float f10 = data[x_extent + i3];
f9 = ((1.0f - f6) * (f7 - f10) + f10 + (f8 - f10) * f5) * HEIGHTMAP_SCALE;
float top_neighbor_height = height_data[map_width + current_point_index];
interpolated_height = ((1.0f - fract_y) * (current_point_height - top_neighbor_height) + top_neighbor_height
+ (top_right_neighbor_height - top_neighbor_height) * fract_x)
* HEIGHTMAP_SCALE;
}

// Calculate the normal vector if pos is provided
if (pos != nullptr) {
int i4 = x_extent * (i2 - 1) + i1;
int i5 = x_extent * i2 + i1;
int i6 = x_extent + i5;
int i7 = x_extent * (i2 + 2) + i1;
unsigned char c1 = data[i5];
unsigned char c2 = data[i5 + 1];
unsigned char c3 = data[x_extent + 1 + i5];
unsigned char c4 = data[x_extent + i5];
unsigned char c5 = data[i4];
unsigned char c6 = data[i4 + 1];
unsigned char c7 = data[i7 + 1];
unsigned char c8 = data[i7];
float f11 = c2 - data[i5 - 1];
float f12 = data[i5 + 2] - c1;
float f13 = data[x_extent + 2 + i5] - c4;
float f14 = c4 - c5;
float f15 = c3 - c6;
float f16 = c7 - c2;
float f17 = c8 - c1;
float f18 = (1.0f - f5) * f11 + f5 * f12;
float f19 = (1.0f - f5) * f12 + f5 * f13;
float f20 = f18 * (1.0f - f6) + f6 * f19;
float f21 = (1.0f - f5) * f14 + f5 * f17;
float f22 = (1.0f - f5) * f15 + f5 * f16;
float f23 = f21 * (1.0f - f6) + f6 * f22;
Vector3 v1;
Vector3 v2;
Vector3 v3;
v1.Set(32.0f, 0.0f, f20);
v2.Set(0.0f, 32.0f, f23);
Vector3::Normalized_Cross_Product(v1, v2, &v3);
pos->x = v3.X;
pos->y = v3.Y;
pos->z = v3.Z;
int prev_row_cell_index = map_width * (index_y - 1) + index_x;
int current_cell_index = map_width * index_y + index_x;
int next_row_cell_index = map_width + current_cell_index;
int next_next_row_cell_index = map_width * (index_y + 2) + index_x;
unsigned char current_cell_height_data = height_data[current_cell_index];
unsigned char right = height_data[current_cell_index + 1];
unsigned char up_right = height_data[map_width + 1 + current_cell_index];
unsigned char up = height_data[map_width + current_cell_index];
unsigned char down = height_data[prev_row_cell_index];
unsigned char down_right = height_data[prev_row_cell_index + 1];
unsigned char up_up_right = height_data[next_next_row_cell_index + 1];
unsigned char up_up = height_data[next_next_row_cell_index];
float slope_1 = right - height_data[current_cell_index - 1];
float slope_2 = height_data[current_cell_index + 2] - current_cell_height_data;
float slope_3 = height_data[map_width + 2 + current_cell_index] - up;
float slope_4 = up - down;
float slope_5 = up_right - down_right;
float slope_6 = up_up_right - right;
float slope_7 = up_up - current_cell_height_data;
float interpolated_slope_x_difference = (1.0f - fract_x) * slope_1 + fract_x * slope_2;
float interpolated_slope_y_difference = (1.0f - fract_x) * slope_2 + fract_x * slope_3;
float interpolated_normal_x =
interpolated_slope_x_difference * (1.0f - fract_y) + fract_y * interpolated_slope_y_difference;
float interpolated_height_x_difference = (1.0f - fract_x) * slope_4 + fract_x * slope_7;
float interpolated_height_y_difference = (1.0f - fract_x) * slope_5 + fract_x * slope_6;
float interpolated_normal_y =
interpolated_height_x_difference * (1.0f - fract_y) + fract_y * interpolated_height_y_difference;
Vector3 v_x_axis;
Vector3 v_y_axis;
Vector3 normal_vector;
v_x_axis.Set(32.0f, 0.0f, interpolated_normal_x);
v_y_axis.Set(0.0f, 32.0f, interpolated_normal_y);
Vector3::Normalized_Cross_Product(v_x_axis, v_y_axis, &normal_vector);
pos->x = normal_vector.X;
pos->y = normal_vector.Y;
pos->z = normal_vector.Z;
}

return f9;
return interpolated_height;
} else {
if (pos != nullptr) {
pos->x = 0.0f;
pos->y = 0.0f;
pos->z = 1.0f;
}

return Get_Clip_Height(i1, i2) * HEIGHTMAP_SCALE;
return Get_Clip_Height(index_x, index_y) * HEIGHTMAP_SCALE;
}
} else {
if (pos) {
if (pos != nullptr) {
pos->x = 0.0f;
pos->y = 0.0f;
pos->z = 1.0f;
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