Line data Source code
1 : /* Copyright (C) 2022 Wildfire Games.
2 : * This file is part of 0 A.D.
3 : *
4 : * 0 A.D. is free software: you can redistribute it and/or modify
5 : * it under the terms of the GNU General Public License as published by
6 : * the Free Software Foundation, either version 2 of the License, or
7 : * (at your option) any later version.
8 : *
9 : * 0 A.D. is distributed in the hope that it will be useful,
10 : * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 : * GNU General Public License for more details.
13 : *
14 : * You should have received a copy of the GNU General Public License
15 : * along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
16 : */
17 :
18 : #include "precompiled.h"
19 :
20 : #include "TexturedLineRData.h"
21 :
22 : #include "graphics/ShaderProgram.h"
23 : #include "graphics/Terrain.h"
24 : #include "maths/Frustum.h"
25 : #include "maths/MathUtil.h"
26 : #include "maths/Quaternion.h"
27 : #include "ps/CStrInternStatic.h"
28 : #include "renderer/OverlayRenderer.h"
29 : #include "renderer/Renderer.h"
30 : #include "simulation2/Simulation2.h"
31 : #include "simulation2/system/SimContext.h"
32 : #include "simulation2/components/ICmpWaterManager.h"
33 :
34 : /* Note: this implementation uses g_VBMan directly rather than access it through the nicer VertexArray interface,
35 : * because it allows you to work with variable amounts of vertices and indices more easily. New code should prefer
36 : * to use VertexArray where possible, though. */
37 :
38 0 : void CTexturedLineRData::Render(
39 : Renderer::Backend::GL::CDeviceCommandContext* deviceCommandContext,
40 : const SOverlayTexturedLine& line, const CShaderProgramPtr& shader)
41 : {
42 0 : if (!m_VB || !m_VBIndices)
43 : return; // might have failed to allocate
44 :
45 : // -- render main line quad strip ----------------------
46 :
47 0 : const int streamFlags = shader->GetStreamFlags();
48 :
49 0 : line.m_TextureBase->UploadBackendTextureIfNeeded(deviceCommandContext);
50 0 : line.m_TextureMask->UploadBackendTextureIfNeeded(deviceCommandContext);
51 :
52 0 : m_VBIndices->m_Owner->UploadIfNeeded(deviceCommandContext);
53 :
54 0 : shader->BindTexture(str_baseTex, line.m_TextureBase->GetBackendTexture());
55 0 : shader->BindTexture(str_maskTex, line.m_TextureMask->GetBackendTexture());
56 0 : shader->Uniform(str_objectColor, line.m_Color);
57 :
58 0 : GLsizei stride = sizeof(CTexturedLineRData::SVertex);
59 0 : CTexturedLineRData::SVertex* vertexBase =
60 0 : reinterpret_cast<CTexturedLineRData::SVertex*>(m_VB->m_Owner->Bind(deviceCommandContext));
61 :
62 0 : if (streamFlags & STREAM_POS)
63 0 : shader->VertexPointer(Renderer::Backend::Format::R32G32B32_SFLOAT, stride, &vertexBase->m_Position[0]);
64 :
65 0 : if (streamFlags & STREAM_UV0)
66 0 : shader->TexCoordPointer(GL_TEXTURE0, Renderer::Backend::Format::R32G32_SFLOAT, stride, &vertexBase->m_UVs[0]);
67 :
68 0 : if (streamFlags & STREAM_UV1)
69 0 : shader->TexCoordPointer(GL_TEXTURE1, Renderer::Backend::Format::R32G32_SFLOAT, stride, &vertexBase->m_UVs[0]);
70 :
71 0 : shader->AssertPointersBound();
72 :
73 0 : deviceCommandContext->SetIndexBuffer(m_VBIndices->m_Owner->GetBuffer());
74 0 : deviceCommandContext->DrawIndexed(m_VBIndices->m_Index, m_VBIndices->m_Count, 0);
75 :
76 0 : g_Renderer.GetStats().m_DrawCalls++;
77 0 : g_Renderer.GetStats().m_OverlayTris += m_VBIndices->m_Count/3;
78 : }
79 :
80 0 : void CTexturedLineRData::Update(const SOverlayTexturedLine& line)
81 : {
82 0 : m_VBIndices.Reset();
83 0 : m_VB.Reset();
84 :
85 0 : if (!line.m_SimContext)
86 : {
87 0 : debug_warn(L"[TexturedLineRData] No SimContext set for textured overlay line, cannot render (no terrain data)");
88 0 : return;
89 : }
90 :
91 0 : float v = 0.f;
92 0 : std::vector<SVertex> vertices;
93 0 : std::vector<u16> indices;
94 :
95 0 : const size_t n = line.m_Coords.size(); // number of line points
96 0 : bool closed = line.m_Closed;
97 :
98 0 : ENSURE(n >= 2); // minimum needed to avoid errors (also minimum value to make sense, can't draw a line between 1 point)
99 :
100 : // In each iteration, p1 is the position of vertex i, p0 is i-1, p2 is i+1.
101 : // To avoid slightly expensive terrain computations we cycle these around and
102 : // recompute p2 at the end of each iteration.
103 :
104 0 : CVector3D p0;
105 0 : CVector3D p1(line.m_Coords[0].X, 0, line.m_Coords[0].Y);
106 0 : CVector3D p2(line.m_Coords[1].X, 0, line.m_Coords[1].Y);
107 :
108 0 : if (closed)
109 : // grab the ending point so as to close the loop
110 0 : p0 = CVector3D(line.m_Coords[n - 1].X, 0, line.m_Coords[n - 1].Y);
111 : else
112 : // we don't want to loop around and use the direction towards the other end of the line, so create an artificial p0 that
113 : // extends the p2 -> p1 direction, and use that point instead
114 0 : p0 = p1 + (p1 - p2);
115 :
116 0 : bool p1floating = false;
117 0 : bool p2floating = false;
118 :
119 : // Compute terrain heights, clamped to the water height (and remember whether
120 : // each point was floating on water, for normal computation later)
121 :
122 : // TODO: if we ever support more than one water level per map, recompute this per point
123 0 : CmpPtr<ICmpWaterManager> cmpWaterManager(*line.m_SimContext, SYSTEM_ENTITY);
124 0 : float w = cmpWaterManager ? cmpWaterManager->GetExactWaterLevel(p0.X, p0.Z) : 0.f;
125 :
126 0 : const CTerrain& terrain = line.m_SimContext->GetTerrain();
127 :
128 0 : p0.Y = terrain.GetExactGroundLevel(p0.X, p0.Z);
129 0 : if (p0.Y < w)
130 0 : p0.Y = w;
131 :
132 0 : p1.Y = terrain.GetExactGroundLevel(p1.X, p1.Z);
133 0 : if (p1.Y < w)
134 : {
135 0 : p1.Y = w;
136 0 : p1floating = true;
137 : }
138 :
139 0 : p2.Y = terrain.GetExactGroundLevel(p2.X, p2.Z);
140 0 : if (p2.Y < w)
141 : {
142 0 : p2.Y = w;
143 0 : p2floating = true;
144 : }
145 :
146 0 : for (size_t i = 0; i < n; ++i)
147 : {
148 : // For vertex i, compute bisector of lines (i-1)..(i) and (i)..(i+1)
149 : // perpendicular to terrain normal
150 :
151 : // Normal is vertical if on water, else computed from terrain
152 0 : CVector3D norm;
153 0 : if (p1floating)
154 : norm = CVector3D(0, 1, 0);
155 : else
156 0 : norm = terrain.CalcExactNormal(p1.X, p1.Z);
157 :
158 0 : CVector3D b = ((p1 - p0).Normalized() + (p2 - p1).Normalized()).Cross(norm);
159 :
160 : // Adjust bisector length to match the line thickness, along the line's width
161 0 : float l = b.Dot((p2 - p1).Normalized().Cross(norm));
162 0 : if (fabs(l) > 0.000001f) // avoid unlikely divide-by-zero
163 0 : b *= line.m_Thickness / l;
164 :
165 : // Push vertices and indices for each quad in GL_TRIANGLES order. The two triangles of each quad are indexed using
166 : // the winding orders (BR, BL, TR) and (TR, BL, TL) (where BR is bottom-right of this iteration's quad, TR top-right etc).
167 0 : SVertex vertex1(p1 + b + norm*OverlayRenderer::OVERLAY_VOFFSET, 0.f, v);
168 0 : SVertex vertex2(p1 - b + norm*OverlayRenderer::OVERLAY_VOFFSET, 1.f, v);
169 0 : vertices.push_back(vertex1);
170 0 : vertices.push_back(vertex2);
171 :
172 0 : u16 vertexCount = static_cast<u16>(vertices.size());
173 0 : u16 index1 = vertexCount - 2; // index of vertex1 in this iteration (TR of this quad)
174 0 : u16 index2 = vertexCount - 1; // index of the vertex2 in this iteration (TL of this quad)
175 :
176 0 : if (i == 0)
177 : {
178 : // initial two vertices to continue building triangles from (n must be >= 2 for this to work)
179 0 : indices.push_back(index1);
180 0 : indices.push_back(index2);
181 : }
182 : else
183 : {
184 0 : u16 index1Prev = vertexCount - 4; // index of the vertex1 in the previous iteration (BR of this quad)
185 0 : u16 index2Prev = vertexCount - 3; // index of the vertex2 in the previous iteration (BL of this quad)
186 0 : ENSURE(index1Prev < vertexCount);
187 0 : ENSURE(index2Prev < vertexCount);
188 : // Add two corner points from last iteration and join with one of our own corners to create triangle 1
189 : // (don't need to do this if i == 1 because i == 0 are the first two ones, they don't need to be copied)
190 0 : if (i > 1)
191 : {
192 0 : indices.push_back(index1Prev);
193 0 : indices.push_back(index2Prev);
194 : }
195 0 : indices.push_back(index1); // complete triangle 1
196 :
197 : // create triangle 2, specifying the adjacent side's vertices in the opposite order from triangle 1
198 0 : indices.push_back(index1);
199 0 : indices.push_back(index2Prev);
200 0 : indices.push_back(index2);
201 : }
202 :
203 : // alternate V coordinate for debugging
204 0 : v = 1 - v;
205 :
206 : // cycle the p's and compute the new p2
207 0 : p0 = p1;
208 0 : p1 = p2;
209 0 : p1floating = p2floating;
210 :
211 : // if in closed mode, wrap around the coordinate array for p2 -- otherwise, extend linearly
212 0 : if (!closed && i == n-2)
213 : // next iteration is the last point of the line, so create an artificial p2 that extends the p0 -> p1 direction
214 0 : p2 = p1 + (p1 - p0);
215 : else
216 0 : p2 = CVector3D(line.m_Coords[(i + 2) % n].X, 0, line.m_Coords[(i + 2) % n].Y);
217 :
218 0 : p2.Y = terrain.GetExactGroundLevel(p2.X, p2.Z);
219 0 : if (p2.Y < w)
220 : {
221 0 : p2.Y = w;
222 0 : p2floating = true;
223 : }
224 : else
225 : p2floating = false;
226 : }
227 :
228 0 : if (closed)
229 : {
230 : // close the path
231 0 : if (n % 2 == 0)
232 : {
233 0 : u16 vertexCount = static_cast<u16>(vertices.size());
234 0 : indices.push_back(vertexCount - 2);
235 0 : indices.push_back(vertexCount - 1);
236 0 : indices.push_back(0);
237 :
238 0 : indices.push_back(0);
239 0 : indices.push_back(vertexCount - 1);
240 0 : indices.push_back(1);
241 : }
242 : else
243 : {
244 : // add two vertices to have the good UVs for the last quad
245 0 : SVertex vertex1(vertices[0].m_Position, 0.f, 1.f);
246 0 : SVertex vertex2(vertices[1].m_Position, 1.f, 1.f);
247 0 : vertices.push_back(vertex1);
248 0 : vertices.push_back(vertex2);
249 :
250 0 : u16 vertexCount = static_cast<u16>(vertices.size());
251 0 : indices.push_back(vertexCount - 4);
252 0 : indices.push_back(vertexCount - 3);
253 0 : indices.push_back(vertexCount - 2);
254 :
255 0 : indices.push_back(vertexCount - 2);
256 0 : indices.push_back(vertexCount - 3);
257 0 : indices.push_back(vertexCount - 1);
258 : }
259 : }
260 : else
261 : {
262 : // Create start and end caps. On either end, this is done by taking the centroid between the last and second-to-last pair of
263 : // vertices that was generated along the path (i.e. the vertex1's and vertex2's from above), taking a directional vector
264 : // between them, and drawing the line cap in the plane given by the two butt-end corner points plus said vector.
265 0 : std::vector<u16> capIndices;
266 0 : std::vector<SVertex> capVertices;
267 :
268 : // create end cap
269 0 : CreateLineCap(
270 : line,
271 : // the order of these vertices is important here, swapping them produces caps at the wrong side
272 0 : vertices[vertices.size()-2].m_Position, // top-right vertex of last quad
273 0 : vertices[vertices.size()-1].m_Position, // top-left vertex of last quad
274 : // directional vector between centroids of last vertex pair and second-to-last vertex pair
275 0 : (Centroid(vertices[vertices.size()-2], vertices[vertices.size()-1]) - Centroid(vertices[vertices.size()-4], vertices[vertices.size()-3])).Normalized(),
276 0 : line.m_EndCapType,
277 : capVertices,
278 : capIndices
279 : );
280 :
281 0 : for (unsigned i = 0; i < capIndices.size(); i++)
282 0 : capIndices[i] += static_cast<u16>(vertices.size());
283 :
284 0 : vertices.insert(vertices.end(), capVertices.begin(), capVertices.end());
285 0 : indices.insert(indices.end(), capIndices.begin(), capIndices.end());
286 :
287 0 : capIndices.clear();
288 0 : capVertices.clear();
289 :
290 : // create start cap
291 0 : CreateLineCap(
292 : line,
293 : // the order of these vertices is important here, swapping them produces caps at the wrong side
294 0 : vertices[1].m_Position,
295 0 : vertices[0].m_Position,
296 : // directional vector between centroids of first vertex pair and second vertex pair
297 0 : (Centroid(vertices[1], vertices[0]) - Centroid(vertices[3], vertices[2])).Normalized(),
298 0 : line.m_StartCapType,
299 : capVertices,
300 : capIndices
301 : );
302 :
303 0 : for (unsigned i = 0; i < capIndices.size(); i++)
304 0 : capIndices[i] += static_cast<u16>(vertices.size());
305 :
306 0 : vertices.insert(vertices.end(), capVertices.begin(), capVertices.end());
307 0 : indices.insert(indices.end(), capIndices.begin(), capIndices.end());
308 : }
309 :
310 0 : if (vertices.empty() || indices.empty())
311 0 : return;
312 :
313 : // Indices for triangles, so must be multiple of 3.
314 0 : ENSURE(indices.size() % 3 == 0);
315 :
316 0 : m_BoundingBox = CBoundingBoxAligned();
317 0 : for (const SVertex& vertex : vertices)
318 0 : m_BoundingBox += vertex.m_Position;
319 :
320 0 : m_VB = g_VBMan.AllocateChunk(
321 0 : sizeof(SVertex), vertices.size(), Renderer::Backend::GL::CBuffer::Type::VERTEX, false);
322 0 : if (m_VB) // allocation might fail (e.g. due to too many vertices)
323 : {
324 0 : m_VB->m_Owner->UpdateChunkVertices(m_VB.Get(), &vertices[0]); // copy data into VBO
325 :
326 0 : for (size_t k = 0; k < indices.size(); ++k)
327 0 : indices[k] += static_cast<u16>(m_VB->m_Index);
328 :
329 0 : m_VBIndices = g_VBMan.AllocateChunk(
330 0 : sizeof(u16), indices.size(), Renderer::Backend::GL::CBuffer::Type::INDEX, false);
331 0 : if (m_VBIndices)
332 0 : m_VBIndices->m_Owner->UpdateChunkVertices(m_VBIndices.Get(), &indices[0]);
333 : }
334 :
335 : }
336 :
337 0 : void CTexturedLineRData::CreateLineCap(const SOverlayTexturedLine& line, const CVector3D& corner1, const CVector3D& corner2,
338 : const CVector3D& lineDirectionNormal, SOverlayTexturedLine::LineCapType endCapType, std::vector<SVertex>& verticesOut,
339 : std::vector<u16>& indicesOut)
340 : {
341 0 : if (endCapType == SOverlayTexturedLine::LINECAP_FLAT)
342 0 : return; // no action needed, this is the default
343 :
344 : // When not in closed mode, we've created artificial points for the start- and endpoints that extend the line in the
345 : // direction of the first and the last segment, respectively. Thus, we know both the start and endpoints have perpendicular
346 : // butt endings, i.e. the end corner vertices on either side of the line extend perpendicularly from the segment direction.
347 : // That is to say, when viewed from the top, we will have something like
348 : // .
349 : // this: and not like this: /|
350 : // ----+ / |
351 : // | / .
352 : // | /
353 : // ----+ /
354 : //
355 :
356 0 : int roundCapPoints = 8; // amount of points to sample along the semicircle for rounded caps (including corner points)
357 0 : float radius = line.m_Thickness;
358 :
359 0 : CVector3D centerPoint = (corner1 + corner2) * 0.5f;
360 0 : SVertex centerVertex(centerPoint, 0.5f, 0.5f);
361 0 : u16 indexOffset = static_cast<u16>(verticesOut.size()); // index offset in verticesOut from where we start adding our vertices
362 :
363 0 : switch (endCapType)
364 : {
365 0 : case SOverlayTexturedLine::LINECAP_SHARP:
366 0 : {
367 0 : roundCapPoints = 3; // creates only one point directly ahead
368 0 : radius *= 1.5f; // make it a bit sharper (note that we don't use the radius for the butt-end corner points so it should be ok)
369 0 : centerVertex.m_UVs[0] = 0.480f; // slight visual correction to make the texture match up better at the corner points
370 : }
371 0 : FALLTHROUGH;
372 0 : case SOverlayTexturedLine::LINECAP_ROUND:
373 0 : {
374 : // Draw a rounded line cap in the 3D plane of the line specified by the two corner points and the normal vector of the
375 : // line's direction. The terrain normal at the centroid between the two corner points is perpendicular to this plane.
376 : // The way this works is by taking a vector from the corner points' centroid to one of the corner points (which is then
377 : // of radius length), and rotate it around the terrain normal vector in that centroid. This will rotate the vector in
378 : // the line's plane, producing the desired rounded cap.
379 :
380 : // To please OpenGL's winding order, this angle needs to be negated depending on whether we start rotating from
381 : // the (center -> corner1) or (center -> corner2) vector. For the (center -> corner2) vector, we apparently need to use
382 : // the negated angle.
383 0 : float stepAngle = -(float)(M_PI/(roundCapPoints-1));
384 :
385 : // Push the vertices in triangle fan order (easy to generate GL_TRIANGLES indices for afterwards)
386 : // Note that we're manually adding the corner vertices instead of having them be generated by the rotating vector.
387 : // This is because we want to support an overly large radius to make the sharp line ending look sharper.
388 0 : verticesOut.push_back(centerVertex);
389 0 : verticesOut.push_back(SVertex(corner2, 0.f, 0.f));
390 :
391 : // Get the base vector that we will incrementally rotate in the cap plane to produce the radial sample points.
392 : // Normally corner2 - centerPoint would suffice for this since it is of radius length, but we want to support custom
393 : // radii to support tuning the 'sharpness' of sharp end caps (see above)
394 0 : CVector3D rotationBaseVector = (corner2 - centerPoint).Normalized() * radius;
395 : // Calculate the normal vector of the plane in which we're going to be drawing the line cap. This is the vector that
396 : // is perpendicular to both baseVector and the 'lineDirectionNormal' vector indicating the direction of the line.
397 : // Note that we shouldn't use terrain->CalcExactNormal() here because if the line is being rendered on top of water,
398 : // then CalcExactNormal will return the normal vector of the terrain that's underwater (which can be quite funky).
399 0 : CVector3D capPlaneNormal = lineDirectionNormal.Cross(rotationBaseVector).Normalized();
400 :
401 0 : for (int i = 1; i < roundCapPoints - 1; ++i)
402 : {
403 : // Rotate the centerPoint -> corner vector by i*stepAngle radians around the cap plane normal at the center point.
404 0 : CQuaternion quatRotation;
405 0 : quatRotation.FromAxisAngle(capPlaneNormal, i * stepAngle);
406 0 : CVector3D worldPos3D = centerPoint + quatRotation.Rotate(rotationBaseVector);
407 :
408 : // Let v range from 0 to 1 as we move along the semi-circle, keep u fixed at 0 (i.e. curve the left vertical edge
409 : // of the texture around the edge of the semicircle)
410 0 : float u = 0.f;
411 0 : float v = Clamp((i / static_cast<float>(roundCapPoints - 1)), 0.f, 1.f); // pos, u, v
412 0 : verticesOut.push_back(SVertex(worldPos3D, u, v));
413 : }
414 :
415 : // connect back to the other butt-end corner point to complete the semicircle
416 0 : verticesOut.push_back(SVertex(corner1, 0.f, 1.f));
417 :
418 : // now push indices in GL_TRIANGLES order; vertices[indexOffset] is the center vertex, vertices[indexOffset + 1] is the
419 : // first corner point, then a bunch of radial samples, and then at the end we have the other corner point again. So:
420 0 : for (int i=1; i < roundCapPoints; ++i)
421 : {
422 0 : indicesOut.push_back(indexOffset); // center vertex
423 0 : indicesOut.push_back(indexOffset + i);
424 0 : indicesOut.push_back(indexOffset + i + 1);
425 0 : }
426 : }
427 0 : break;
428 :
429 0 : case SOverlayTexturedLine::LINECAP_SQUARE:
430 0 : {
431 : // Extend the (corner1 -> corner2) vector along the direction normal and draw a square line ending consisting of
432 : // three triangles (sort of like a triangle fan)
433 : // NOTE: The order in which the vertices are pushed out determines the visibility, as they
434 : // are rendered only one-sided; the wrong order of vertices will make the cap visible only from the bottom.
435 0 : verticesOut.push_back(centerVertex);
436 0 : verticesOut.push_back(SVertex(corner2, 0.f, 0.f));
437 0 : verticesOut.push_back(SVertex(corner2 + (lineDirectionNormal * (line.m_Thickness)), 0.f, 0.33333f)); // extend butt corner point 2 along the normal vector
438 0 : verticesOut.push_back(SVertex(corner1 + (lineDirectionNormal * (line.m_Thickness)), 0.f, 0.66666f)); // extend butt corner point 1 along the normal vector
439 0 : verticesOut.push_back(SVertex(corner1, 0.f, 1.0f)); // push butt corner point 1
440 :
441 0 : for (int i=1; i < 4; ++i)
442 : {
443 0 : indicesOut.push_back(indexOffset); // center point
444 0 : indicesOut.push_back(indexOffset + i);
445 0 : indicesOut.push_back(indexOffset + i + 1);
446 0 : }
447 : }
448 : break;
449 :
450 : default:
451 : break;
452 : }
453 :
454 : }
455 :
456 0 : bool CTexturedLineRData::IsVisibleInFrustum(const CFrustum& frustum) const
457 : {
458 0 : return frustum.IsBoxVisible(m_BoundingBox);
459 : }
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