Use indexed faces (#257)

miniwin/CMakeLists.txt

@@ -15,6 +15,7 @@ add_library(miniwin STATIC EXCLUDE_FROM_ALL
   src/d3drm/d3drmmesh.cpp
   src/d3drm/d3drmtexture.cpp
   src/d3drm/d3drmviewport.cpp
+  src/internal/meshutils.cpp
 
   # D3DRM backends
   src/d3drm/backends/software/renderer.cpp

miniwin/include/miniwin/d3drm.h

@@ -191,8 +191,8 @@ struct IDirect3DRMMesh : public IDirect3DRMVisual {
 		DWORD* vertexCount,
 		DWORD* faceCount,
 		DWORD* vertexPerFace,
-		DWORD* dataSize,
+		DWORD* indexCount,
-		DWORD* data
+		DWORD* indices
 	) = 0;
 	virtual DWORD GetGroupCount() = 0;
 	virtual HRESULT SetGroupColor(DWORD groupIndex, D3DCOLOR color) = 0;

miniwin/src/d3drm/backends/opengl15/renderer.cpp

@@ -2,8 +2,10 @@
 #include "ddraw_impl.h"
 #include "ddsurface_impl.h"
 #include "mathutils.h"
+#include "meshutils.h"
 
 #include <GL/glew.h>
+#include <algorithm>
 #include <cstring>
 #include <vector>
 
@@ -305,7 +307,9 @@ HRESULT OpenGL15Renderer::BeginFrame(const D3DRMMATRIX4D& viewMatrix)
 
 void OpenGL15Renderer::SubmitDraw(
 	const D3DRMVERTEX* vertices,
-	const size_t count,
+	const size_t vertexCount,
+	const DWORD* indices,
+	const size_t indexCount,
 	const D3DRMMATRIX4D& worldMatrix,
 	const Matrix3x3& normalMatrix,
 	const Appearance& appearance
@@ -319,27 +323,46 @@ void OpenGL15Renderer::SubmitDraw(
 	glLoadMatrixf(&mvMatrix[0][0]);
 	glEnable(GL_NORMALIZE);
 
-	glColor4ub(appearance.color.r, appearance.color.g, appearance.color.b, appearance.color.a);
+	std::vector<D3DRMVERTEX> newVertices;
-
+	std::vector<DWORD> newIndices;
-	// Bind texture if present
-	if (appearance.textureId != NO_TEXTURE_ID) {
-		auto& tex = m_textures[appearance.textureId];
-		if (tex.glTextureId) {
-			glEnable(GL_TEXTURE_2D);
-			glBindTexture(GL_TEXTURE_2D, tex.glTextureId);
-		}
-	}
-	else {
-		glDisable(GL_TEXTURE_2D);
-	}
-
 	if (appearance.flat) {
 		glShadeModel(GL_FLAT);
+		// FIXME move this to a one time mesh upload stage
+		FlattenSurfaces(
+			vertices,
+			vertexCount,
+			indices,
+			indexCount,
+			appearance.textureId != NO_TEXTURE_ID,
+			newVertices,
+			newIndices
+		);
 	}
 	else {
 		glShadeModel(GL_SMOOTH);
+		newVertices.assign(vertices, vertices + vertexCount);
+		newIndices.assign(indices, indices + indexCount);
 	}
 
+	// Bind texture if present
+	std::vector<TexCoord> texcoords;
+	if (appearance.textureId != NO_TEXTURE_ID) {
+		auto& tex = m_textures[appearance.textureId];
+		glEnable(GL_TEXTURE_2D);
+		glBindTexture(GL_TEXTURE_2D, tex.glTextureId);
+		glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+		texcoords.resize(newVertices.size());
+		std::transform(newVertices.begin(), newVertices.end(), texcoords.begin(), [](const D3DRMVERTEX& v) {
+			return v.texCoord;
+		});
+	}
+	else {
+		glDisable(GL_TEXTURE_2D);
+		glDisableClientState(GL_TEXTURE_COORD_ARRAY);
+	}
+
+	glColor4ub(appearance.color.r, appearance.color.g, appearance.color.b, appearance.color.a);
+
 	float shininess = appearance.shininess;
 	glMaterialf(GL_FRONT, GL_SHININESS, shininess);
 	if (shininess != 0.0f) {
@@ -351,14 +374,29 @@ void OpenGL15Renderer::SubmitDraw(
 		glMaterialfv(GL_FRONT, GL_SPECULAR, noSpec);
 	}
 
-	glBegin(GL_TRIANGLES);
+	std::vector<D3DVECTOR> positions;
-	for (size_t i = 0; i < count; i++) {
+	positions.resize(newVertices.size());
-		const D3DRMVERTEX& v = vertices[i];
+	std::transform(newVertices.begin(), newVertices.end(), positions.begin(), [](const D3DRMVERTEX& v) {
-		glNormal3f(v.normal.x, v.normal.y, v.normal.z);
+		return v.position;
-		glTexCoord2f(v.texCoord.u, v.texCoord.v);
+	});
-		glVertex3f(v.position.x, v.position.y, v.position.z);
+	std::vector<D3DVECTOR> normals;
+	normals.resize(newVertices.size());
+	std::transform(newVertices.begin(), newVertices.end(), normals.begin(), [](const D3DRMVERTEX& v) {
+		return v.normal;
+	});
+
+	glEnableClientState(GL_VERTEX_ARRAY);
+	glVertexPointer(3, GL_FLOAT, 0, positions.data());
+
+	glEnableClientState(GL_NORMAL_ARRAY);
+	glNormalPointer(GL_FLOAT, 0, normals.data());
+
+	if (appearance.textureId != NO_TEXTURE_ID) {
+		glTexCoordPointer(2, GL_FLOAT, 0, texcoords.data());
 	}
-	glEnd();
+
+	// Draw triangles
+	glDrawElements(GL_TRIANGLES, static_cast<GLsizei>(newIndices.size()), GL_UNSIGNED_INT, newIndices.data());
 
 	glPopMatrix();
 }

miniwin/src/d3drm/backends/sdl3gpu/renderer.cpp

@@ -3,6 +3,7 @@
 #include "d3drmrenderer_sdl3gpu.h"
 #include "ddraw_impl.h"
 #include "mathutils.h"
+#include "meshutils.h"
 #include "miniwin.h"
 
 #include <SDL3/SDL.h>
@@ -600,7 +601,9 @@ SDL_GPUTransferBuffer* Direct3DRMSDL3GPURenderer::GetUploadBuffer(size_t size)
 
 void Direct3DRMSDL3GPURenderer::SubmitDraw(
 	const D3DRMVERTEX* vertices,
-	const size_t count,
+	const size_t vertexCount,
+	const DWORD* indices,
+	const size_t indexCount,
 	const D3DRMMATRIX4D& worldMatrix,
 	const Matrix3x3& normalMatrix,
 	const Appearance& appearance
@@ -613,21 +616,46 @@ void Direct3DRMSDL3GPURenderer::SubmitDraw(
 	m_fragmentShadingData.color = appearance.color;
 	m_fragmentShadingData.shininess = appearance.shininess;
 
-	if (count > m_vertexBufferCount) {
+	std::vector<D3DRMVERTEX> flatVertices;
+	if (appearance.flat) {
+		std::vector<D3DRMVERTEX> newVertices;
+		std::vector<DWORD> newIndices;
+		// FIXME move this to a one time mesh upload stage
+		FlattenSurfaces(
+			vertices,
+			vertexCount,
+			indices,
+			indexCount,
+			appearance.textureId != NO_TEXTURE_ID,
+			newVertices,
+			newIndices
+		);
+		for (DWORD& index : newIndices) {
+			flatVertices.push_back(newVertices[index]);
+		}
+	}
+	else {
+		// TODO handle indexed verticies on GPU
+		for (int i = 0; i < indexCount; ++i) {
+			flatVertices.push_back(vertices[indices[i]]);
+		}
+	}
+
+	if (flatVertices.size() > m_vertexBufferCount) {
 		if (m_vertexBuffer) {
 			SDL_ReleaseGPUBuffer(m_device, m_vertexBuffer);
 		}
 		SDL_GPUBufferCreateInfo bufferCreateInfo = {};
 		bufferCreateInfo.usage = SDL_GPU_BUFFERUSAGE_VERTEX;
-		bufferCreateInfo.size = static_cast<Uint32>(sizeof(D3DRMVERTEX) * count);
+		bufferCreateInfo.size = static_cast<Uint32>(sizeof(D3DRMVERTEX) * flatVertices.size());
 		m_vertexBuffer = SDL_CreateGPUBuffer(m_device, &bufferCreateInfo);
 		if (!m_vertexBuffer) {
 			SDL_LogError(LOG_CATEGORY_MINIWIN, "SDL_CreateGPUBuffer failed (%s)", SDL_GetError());
 		}
-		m_vertexBufferCount = count;
+		m_vertexBufferCount = flatVertices.size();
 	}
 
-	m_vertexCount = count;
+	m_vertexCount = flatVertices.size();
 
 	SDL_GPUTransferBuffer* uploadBuffer = GetUploadBuffer(sizeof(D3DRMVERTEX) * m_vertexCount);
 	if (!uploadBuffer) {
@@ -639,7 +667,7 @@ void Direct3DRMSDL3GPURenderer::SubmitDraw(
 		return;
 	}
 
-	memcpy(transferData, vertices, m_vertexCount * sizeof(D3DRMVERTEX));
+	memcpy(transferData, flatVertices.data(), m_vertexCount * sizeof(D3DRMVERTEX));
 	SDL_UnmapGPUTransferBuffer(m_device, uploadBuffer);
 
 	// Upload the transfer data to the vertex buffer

miniwin/src/d3drm/backends/software/renderer.cpp

@@ -2,6 +2,7 @@
 #include "d3drmrenderer_software.h"
 #include "ddsurface_impl.h"
 #include "mathutils.h"
+#include "meshutils.h"
 #include "miniwin.h"
 
 #include <SDL3/SDL.h>
@@ -452,7 +453,9 @@ HRESULT Direct3DRMSoftwareRenderer::BeginFrame(const D3DRMMATRIX4D& viewMatrix)
 
 void Direct3DRMSoftwareRenderer::SubmitDraw(
 	const D3DRMVERTEX* vertices,
-	const size_t count,
+	const size_t vertexCount,
+	const DWORD* indices,
+	const size_t indexCount,
 	const D3DRMMATRIX4D& worldMatrix,
 	const Matrix3x3& normalMatrix,
 	const Appearance& appearance
@@ -461,15 +464,42 @@ void Direct3DRMSoftwareRenderer::SubmitDraw(
 	D3DRMMATRIX4D mvMatrix;
 	MultiplyMatrix(mvMatrix, worldMatrix, m_viewMatrix);
 
-	for (size_t i = 0; i + 2 < count; i += 3) {
+	std::vector<D3DRMVERTEX> newVertices;
-		D3DRMVERTEX vrts[3];
+	std::vector<DWORD> newIndices;
-		for (size_t j = 0; j < 3; ++j) {
+	if (appearance.flat) {
-			const D3DRMVERTEX& src = vertices[i + j];
+		// FIXME move this to a one time mesh upload stage
-			vrts[j].position = TransformPoint(src.position, mvMatrix);
+		FlattenSurfaces(
-			vrts[j].normal = Normalize(TransformNormal(src.normal, normalMatrix));
+			vertices,
-			vrts[j].texCoord = src.texCoord;
+			vertexCount,
-		}
+			indices,
-		DrawTriangleClipped(vrts, appearance);
+			indexCount,
+			appearance.textureId != NO_TEXTURE_ID,
+			newVertices,
+			newIndices
+		);
+	}
+	else {
+		newVertices.assign(vertices, vertices + vertexCount);
+		newIndices.assign(indices, indices + indexCount);
+	}
+
+	// Pre-transform all vertex positions and normals
+	std::vector<D3DRMVERTEX> transformedVerts(newVertices.size());
+	for (size_t i = 0; i < newVertices.size(); ++i) {
+		const D3DRMVERTEX& src = newVertices[i];
+		D3DRMVERTEX& dst = transformedVerts[i];
+		dst.position = TransformPoint(src.position, mvMatrix);
+		// TODO defer normal transformation til lighting to allow culling first
+		dst.normal = Normalize(TransformNormal(src.normal, normalMatrix));
+		dst.texCoord = src.texCoord;
+	}
+
+	// Assemble triangles using index buffer
+	for (size_t i = 0; i + 2 < newIndices.size(); i += 3) {
+		DrawTriangleClipped(
+			{transformedVerts[newIndices[i]], transformedVerts[newIndices[i + 1]], transformedVerts[newIndices[i + 2]]},
+			appearance
+		);
 	}
 }
 

miniwin/src/d3drm/d3drmmesh.cpp

@@ -60,7 +60,7 @@ HRESULT Direct3DRMMeshImpl::AddGroup(
 	group.vertexPerFace = vertexPerFace;
 
 	DWORD* src = faceBuffer;
-	group.faces.assign(src, src + faceCount * vertexPerFace);
+	group.indices.assign(src, src + faceCount * vertexPerFace);
 
 	m_groups.push_back(std::move(group));
 
@@ -72,8 +72,8 @@ HRESULT Direct3DRMMeshImpl::GetGroup(
 	DWORD* vertexCount,
 	DWORD* faceCount,
 	DWORD* vertexPerFace,
-	DWORD* dataSize,
+	DWORD* indexCount,
-	DWORD* data
+	DWORD* indices
 )
 {
 	if (groupIndex >= m_groups.size()) {
@@ -86,16 +86,16 @@ HRESULT Direct3DRMMeshImpl::GetGroup(
 		*vertexCount = static_cast<DWORD>(group.vertices.size());
 	}
 	if (faceCount) {
-		*faceCount = static_cast<DWORD>(group.faces.size() / group.vertexPerFace);
+		*faceCount = static_cast<DWORD>(group.indices.size() / group.vertexPerFace);
 	}
 	if (vertexPerFace) {
 		*vertexPerFace = static_cast<DWORD>(group.vertexPerFace);
 	}
-	if (dataSize) {
+	if (indexCount) {
-		*dataSize = static_cast<DWORD>(group.faces.size());
+		*indexCount = static_cast<DWORD>(group.indices.size());
 	}
-	if (data) {
+	if (indices) {
-		std::copy(group.faces.begin(), group.faces.end(), reinterpret_cast<unsigned int*>(data));
+		std::copy(group.indices.begin(), group.indices.end(), reinterpret_cast<unsigned int*>(indices));
 	}
 
 	return DD_OK;

miniwin/src/d3drm/d3drmviewport.cpp

@@ -95,21 +95,6 @@ static void ComputeFrameWorldMatrix(IDirect3DRMFrame* frame, D3DRMMATRIX4D out)
 	memcpy(out, acc, sizeof(acc));
 }
 
-inline D3DVECTOR CrossProduct(const D3DVECTOR& a, const D3DVECTOR& b)
-{
-	return {a.y * b.z - a.z * b.y, a.z * b.x - a.x * b.z, a.x * b.y - a.y * b.x};
-}
-
-D3DVECTOR ComputeTriangleNormal(const D3DVECTOR& v0, const D3DVECTOR& v1, const D3DVECTOR& v2)
-{
-	D3DVECTOR u = {v1.x - v0.x, v1.y - v0.y, v1.z - v0.z};
-	D3DVECTOR v = {v2.x - v0.x, v2.y - v0.y, v2.z - v0.z};
-	D3DVECTOR normal = CrossProduct(u, v);
-	normal = Normalize(normal);
-
-	return normal;
-}
-
 void Direct3DRMViewportImpl::CollectLightsFromFrame(
 	IDirect3DRMFrame* frame,
 	D3DRMMATRIX4D parentToWorld,
@@ -215,9 +200,8 @@ bool IsBoxInFrustum(const D3DVECTOR corners[8], const Plane planes[6])
 void Direct3DRMViewportImpl::CollectMeshesFromFrame(
 	IDirect3DRMFrame* frame,
 	D3DRMMATRIX4D parentMatrix,
-	std::vector<D3DRMVERTEX>& verts,
 	std::vector<D3DRMVERTEX>& d3dVerts,
-	std::vector<DWORD>& faces
+	std::vector<DWORD>& indices
 )
 {
 	Direct3DRMFrameImpl* frameImpl = static_cast<Direct3DRMFrameImpl*>(frame);
@@ -240,7 +224,7 @@ void Direct3DRMViewportImpl::CollectMeshesFromFrame(
 		IDirect3DRMFrame* childFrame = nullptr;
 		visual->QueryInterface(IID_IDirect3DRMFrame, (void**) &childFrame);
 		if (childFrame) {
-			CollectMeshesFromFrame(childFrame, worldMatrix, verts, d3dVerts, faces);
+			CollectMeshesFromFrame(childFrame, worldMatrix, d3dVerts, indices);
 			childFrame->Release();
 			visual->Release();
 			continue;
@@ -276,19 +260,16 @@ void Direct3DRMViewportImpl::CollectMeshesFromFrame(
 
 		DWORD groupCount = mesh->GetGroupCount();
 		for (DWORD gi = 0; gi < groupCount; ++gi) {
-			DWORD vtxCount, faceCount, vpf, dataSize;
+			DWORD vtxCount, indexCount;
-			mesh->GetGroup(gi, &vtxCount, &faceCount, &vpf, &dataSize, nullptr);
+			mesh->GetGroup(gi, &vtxCount, nullptr, nullptr, &indexCount, nullptr);
 
-			verts.reserve(dataSize);
-			verts.clear();
 			d3dVerts.resize(vtxCount);
-			faces.resize(dataSize);
+			indices.resize(indexCount);
 			mesh->GetVertices(gi, 0, vtxCount, d3dVerts.data());
-			mesh->GetGroup(gi, nullptr, nullptr, nullptr, nullptr, faces.data());
+			mesh->GetGroup(gi, nullptr, nullptr, nullptr, nullptr, indices.data());
 
 			D3DCOLOR color = mesh->GetGroupColor(gi);
 			D3DRMRENDERQUALITY quality = mesh->GetGroupQuality(gi);
-			bool flat = quality == D3DRMRENDER_FLAT || quality == D3DRMRENDER_UNLITFLAT;
 
 			IDirect3DRMTexture* texture = nullptr;
 			mesh->GetGroupTexture(gi, &texture);
@@ -306,28 +287,11 @@ void Direct3DRMViewportImpl::CollectMeshesFromFrame(
 				material->Release();
 			}
 
-			for (DWORD fi = 0; fi < faceCount; ++fi) {
-				D3DVECTOR norm;
-				if (flat) {
-					D3DRMVERTEX& v0 = d3dVerts[faces[fi * vpf + 0]];
-					D3DRMVERTEX& v1 = d3dVerts[faces[fi * vpf + 1]];
-					D3DRMVERTEX& v2 = d3dVerts[faces[fi * vpf + 2]];
-					norm = ComputeTriangleNormal(v0.position, v1.position, v2.position);
-				}
-
-				for (DWORD idx = 0; idx < vpf; ++idx) {
-					D3DRMVERTEX& dv = d3dVerts[faces[fi * vpf + idx]];
-					D3DVECTOR pos = dv.position;
-					if (quality == D3DRMRENDER_GOURAUD || quality == D3DRMRENDER_PHONG) {
-						norm = dv.normal;
-					}
-
-					verts.push_back({pos, norm, {dv.tu, dv.tv}});
-				}
-			}
 			m_renderer->SubmitDraw(
-				verts.data(),
+				d3dVerts.data(),
-				verts.size(),
+				d3dVerts.size(),
+				indices.data(),
+				indices.size(),
 				worldMatrix,
 				worldMatrixInvert,
 				{{static_cast<Uint8>((color >> 16) & 0xFF),
@@ -336,7 +300,7 @@ void Direct3DRMViewportImpl::CollectMeshesFromFrame(
 				  static_cast<Uint8>((color >> 24) & 0xFF)},
 				 shininess,
 				 textureId,
-				 flat}
+				 quality == D3DRMRENDER_FLAT || quality == D3DRMRENDER_UNLITFLAT}
 			);
 		}
 		mesh->Release();
@@ -365,11 +329,10 @@ HRESULT Direct3DRMViewportImpl::RenderScene()
 		return status;
 	}
 
-	std::vector<D3DRMVERTEX> verts;
 	std::vector<D3DRMVERTEX> d3dVerts;
-	std::vector<DWORD> faces;
+	std::vector<DWORD> indices;
 	ExtractFrustumPlanes(viewProj);
-	CollectMeshesFromFrame(m_rootFrame, identity, verts, d3dVerts, faces);
+	CollectMeshesFromFrame(m_rootFrame, identity, d3dVerts, indices);
 	return m_renderer->FinalizeFrame();
 }
 
@@ -724,23 +687,19 @@ bool RayIntersectsMeshTriangles(
 {
 	DWORD groupCount = mesh->GetGroupCount();
 	for (DWORD g = 0; g < groupCount; ++g) {
-		DWORD vtxCount = 0, faceCount = 0, vpf = 0, dataSize = 0;
+		DWORD vtxCount, faceCount, indexCount;
-		mesh->GetGroup(g, &vtxCount, &faceCount, &vpf, &dataSize, nullptr);
+		mesh->GetGroup(g, &vtxCount, &faceCount, nullptr, &indexCount, nullptr);
 
 		std::vector<D3DRMVERTEX> vertices(vtxCount);
 		mesh->GetVertices(g, 0, vtxCount, vertices.data());
-		std::vector<DWORD> faces(faceCount * vpf);
+		std::vector<DWORD> indices(indexCount);
-		mesh->GetGroup(g, nullptr, nullptr, nullptr, nullptr, faces.data());
+		mesh->GetGroup(g, nullptr, nullptr, nullptr, nullptr, indices.data());
 
 		// Iterate over each face and do ray-triangle tests
-		for (DWORD fi = 0; fi < faceCount; ++fi) {
+		for (DWORD fi = 0; fi < faceCount; fi += 3) {
-			DWORD i0 = faces[fi * vpf + 0];
+			DWORD i0 = indices[fi + 0];
-			DWORD i1 = faces[fi * vpf + 1];
+			DWORD i1 = indices[fi + 1];
-			DWORD i2 = faces[fi * vpf + 2];
+			DWORD i2 = indices[fi + 2];
-
-			if (i0 >= vtxCount || i1 >= vtxCount || i2 >= vtxCount) {
-				continue;
-			}
 
 			// Transform vertices to world space
 			D3DVECTOR tri[3];

miniwin/src/internal/d3drmmesh_impl.h

@@ -12,13 +12,13 @@ struct MeshGroup {
 	D3DRMRENDERQUALITY quality = D3DRMRENDER_GOURAUD;
 	int vertexPerFace = 0;
 	std::vector<D3DRMVERTEX> vertices;
-	std::vector<unsigned int> faces;
+	std::vector<unsigned int> indices;
 
 	MeshGroup() = default;
 
 	MeshGroup(const MeshGroup& other)
 		: color(other.color), texture(other.texture), material(other.material), quality(other.quality),
-		  vertexPerFace(other.vertexPerFace), vertices(std::move(other.vertices)), faces(std::move(other.faces))
+		  vertexPerFace(other.vertexPerFace), vertices(std::move(other.vertices)), indices(std::move(other.indices))
 	{
 		if (texture) {
 			texture->AddRef();
@@ -31,7 +31,7 @@ struct MeshGroup {
 	// Move constructor
 	MeshGroup(MeshGroup&& other) noexcept
 		: color(other.color), texture(other.texture), material(other.material), quality(other.quality),
-		  vertexPerFace(other.vertexPerFace), vertices(other.vertices), faces(other.faces)
+		  vertexPerFace(other.vertexPerFace), vertices(other.vertices), indices(other.indices)
 	{
 		other.texture = nullptr;
 		other.material = nullptr;
@@ -46,7 +46,7 @@ struct MeshGroup {
 		quality = other.quality;
 		vertexPerFace = other.vertexPerFace;
 		vertices = std::move(other.vertices);
-		faces = std::move(other.faces);
+		indices = std::move(other.indices);
 		other.texture = nullptr;
 		other.material = nullptr;
 		return *this;
@@ -73,8 +73,8 @@ struct Direct3DRMMeshImpl : public Direct3DRMObjectBaseImpl<IDirect3DRMMesh> {
 		DWORD* vertexCount,
 		DWORD* faceCount,
 		DWORD* vertexPerFace,
-		DWORD* dataSize,
+		DWORD* indexCount,
-		DWORD* data
+		DWORD* indices
 	) override;
 	DWORD GetGroupCount() override;
 	HRESULT SetGroupColor(DWORD groupIndex, D3DCOLOR color) override;

miniwin/src/internal/d3drmrenderer.h

@@ -13,7 +13,7 @@ struct Appearance {
 	SDL_Color color;
 	float shininess;
 	Uint32 textureId;
-	bool flat;
+	Uint32 flat;
 };
 
 struct FColor {
@@ -41,7 +41,9 @@ class Direct3DRMRenderer : public IDirect3DDevice2 {
 	virtual HRESULT BeginFrame(const D3DRMMATRIX4D& viewMatrix) = 0;
 	virtual void SubmitDraw(
 		const D3DRMVERTEX* vertices,
-		const size_t count,
+		const size_t vertexCount,
+		const DWORD* indices,
+		const size_t indexCount,
 		const D3DRMMATRIX4D& worldMatrix,
 		const Matrix3x3& normalMatrix,
 		const Appearance& appearance

miniwin/src/internal/d3drmrenderer_opengl15.h

@@ -31,7 +31,9 @@ class OpenGL15Renderer : public Direct3DRMRenderer {
 	HRESULT BeginFrame(const D3DRMMATRIX4D& viewMatrix) override;
 	void SubmitDraw(
 		const D3DRMVERTEX* vertices,
-		const size_t count,
+		const size_t vertexCount,
+		const DWORD* indices,
+		const size_t indexCount,
 		const D3DRMMATRIX4D& worldMatrix,
 		const Matrix3x3& normalMatrix,
 		const Appearance& appearance

miniwin/src/internal/d3drmrenderer_sdl3gpu.h

@@ -48,7 +48,9 @@ class Direct3DRMSDL3GPURenderer : public Direct3DRMRenderer {
 	HRESULT BeginFrame(const D3DRMMATRIX4D& viewMatrix) override;
 	void SubmitDraw(
 		const D3DRMVERTEX* vertices,
-		const size_t count,
+		const size_t vertexCount,
+		const DWORD* indices,
+		const size_t indexCount,
 		const D3DRMMATRIX4D& worldMatrix,
 		const Matrix3x3& normalMatrix,
 		const Appearance& appearance

miniwin/src/internal/d3drmrenderer_software.h

@@ -29,7 +29,9 @@ class Direct3DRMSoftwareRenderer : public Direct3DRMRenderer {
 	HRESULT BeginFrame(const D3DRMMATRIX4D& viewMatrix) override;
 	void SubmitDraw(
 		const D3DRMVERTEX* vertices,
-		const size_t count,
+		const size_t vertexCount,
+		const DWORD* indices,
+		const size_t indexCount,
 		const D3DRMMATRIX4D& worldMatrix,
 		const Matrix3x3& normalMatrix,
 		const Appearance& appearance

miniwin/src/internal/d3drmviewport_impl.h

@@ -40,7 +40,6 @@ struct Direct3DRMViewportImpl : public Direct3DRMObjectBaseImpl<IDirect3DRMViewp
 	void CollectMeshesFromFrame(
 		IDirect3DRMFrame* frame,
 		D3DRMMATRIX4D parentMatrix,
-		std::vector<D3DRMVERTEX>& verts,
 		std::vector<D3DRMVERTEX>& d3dVerts,
 		std::vector<DWORD>& faces
 	);

miniwin/src/internal/mathutils.h

@@ -25,6 +25,11 @@ inline D3DVECTOR Normalize(const D3DVECTOR& v)
 	return {0, 0, 0};
 }
 
+inline D3DVECTOR CrossProduct(const D3DVECTOR& a, const D3DVECTOR& b)
+{
+	return {a.y * b.z - a.z * b.y, a.z * b.x - a.x * b.z, a.x * b.y - a.y * b.x};
+}
+
 inline D3DVECTOR TransformPoint(const D3DVECTOR& p, const D3DRMMATRIX4D& m)
 {
 	return {

miniwin/src/internal/meshutils.cpp

@@ -0,0 +1,77 @@
+#include "meshutils.h"
+
+#include "mathutils.h"
+
+#include <tuple>
+#include <unordered_map>
+
+bool operator==(const D3DRMVERTEX& a, const D3DRMVERTEX& b)
+{
+	return memcmp(&a, &b, sizeof(D3DRMVERTEX)) == 0;
+}
+
+namespace std
+{
+template <>
+struct hash<D3DRMVERTEX> {
+	size_t operator()(const D3DRMVERTEX& v) const
+	{
+		const float* f = reinterpret_cast<const float*>(&v);
+		size_t h = 0;
+		for (int i = 0; i < sizeof(D3DRMVERTEX) / sizeof(float); ++i) {
+			h ^= std::hash<float>()(f[i]) + 0x9e3779b9 + (h << 6) + (h >> 2);
+		}
+		return h;
+	}
+};
+} // namespace std
+
+D3DVECTOR ComputeTriangleNormal(const D3DVECTOR& v0, const D3DVECTOR& v1, const D3DVECTOR& v2)
+{
+	D3DVECTOR u = {v1.x - v0.x, v1.y - v0.y, v1.z - v0.z};
+	D3DVECTOR v = {v2.x - v0.x, v2.y - v0.y, v2.z - v0.z};
+	D3DVECTOR normal = CrossProduct(u, v);
+	normal = Normalize(normal);
+
+	return normal;
+}
+
+void FlattenSurfaces(
+	const D3DRMVERTEX* vertices,
+	const size_t vertexCount,
+	const DWORD* indices,
+	const size_t indexCount,
+	bool hasTexture,
+	std::vector<D3DRMVERTEX>& dedupedVertices,
+	std::vector<DWORD>& newIndices
+)
+{
+	std::unordered_map<D3DRMVERTEX, DWORD> uniqueVertexMap;
+
+	dedupedVertices.reserve(vertexCount);
+	newIndices.reserve(indexCount);
+
+	for (size_t i = 0; i < indexCount; i += 3) {
+		D3DRMVERTEX v0 = vertices[indices[i + 0]];
+		D3DRMVERTEX v1 = vertices[indices[i + 1]];
+		D3DRMVERTEX v2 = vertices[indices[i + 2]];
+		v0.normal = v1.normal = v2.normal = ComputeTriangleNormal(v0.position, v1.position, v2.position);
+		if (!hasTexture) {
+			v0.texCoord = v1.texCoord = v2.texCoord = {0.0f, 0.0f};
+		}
+
+		// Deduplicate vertecies
+		for (const D3DRMVERTEX& v : {v0, v1, v2}) {
+			auto it = uniqueVertexMap.find(v);
+			if (it != uniqueVertexMap.end()) {
+				newIndices.push_back(it->second);
+			}
+			else {
+				DWORD newIndex = static_cast<DWORD>(dedupedVertices.size());
+				uniqueVertexMap[v] = newIndex;
+				dedupedVertices.push_back(v);
+				newIndices.push_back(newIndex);
+			}
+		}
+	}
+}

miniwin/src/internal/meshutils.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include "miniwin/d3drm.h"
+
+#include <vector>
+
+void FlattenSurfaces(
+	const D3DRMVERTEX* vertices,
+	const size_t vertexCount,
+	const DWORD* indices,
+	const size_t indexCount,
+	bool hasTexture,
+	std::vector<D3DRMVERTEX>& dedupedVertices,
+	std::vector<DWORD>& newIndices
+);