From 3dfe2108cfab31ba3ee5527e217d0d8e99a51162 Mon Sep 17 00:00:00 2001
From: git perforce import user <a@b>
Date: Tue, 25 Oct 2016 12:29:14 -0600
Subject: Initial commit: PhysX 3.4.0 Update @ 21294896 APEX 1.4.0 Update @
 21275617

[CL 21300167]
---
 KaplaDemo/samples/sampleViewer3/ShadowMap.cpp | 383 ++++++++++++++++++++++++++
 1 file changed, 383 insertions(+)
 create mode 100644 KaplaDemo/samples/sampleViewer3/ShadowMap.cpp

(limited to 'KaplaDemo/samples/sampleViewer3/ShadowMap.cpp')

diff --git a/KaplaDemo/samples/sampleViewer3/ShadowMap.cpp b/KaplaDemo/samples/sampleViewer3/ShadowMap.cpp
new file mode 100644
index 00000000..cf9caea3
--- /dev/null
+++ b/KaplaDemo/samples/sampleViewer3/ShadowMap.cpp
@@ -0,0 +1,383 @@
+//----------------------------------------------------------------------------------
+// File:   ShadowMapping.cpp
+// Original Author: Rouslan Dimitrov
+// Modified by: Nuttapong Chentanez and Matthias Müller-Fischer
+// Email:  sdkfeedback@nvidia.com
+// 
+// Copyright (c) 2007 NVIDIA Corporation. All rights reserved.
+//
+// TO  THE MAXIMUM  EXTENT PERMITTED  BY APPLICABLE  LAW, THIS SOFTWARE  IS PROVIDED
+// *AS IS*  AND NVIDIA AND  ITS SUPPLIERS DISCLAIM  ALL WARRANTIES,  EITHER  EXPRESS
+// OR IMPLIED, INCLUDING, BUT NOT LIMITED  TO, IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL  NVIDIA OR ITS SUPPLIERS
+// BE  LIABLE  FOR  ANY  SPECIAL,  INCIDENTAL,  INDIRECT,  OR  CONSEQUENTIAL DAMAGES
+// WHATSOEVER (INCLUDING, WITHOUT LIMITATION,  DAMAGES FOR LOSS OF BUSINESS PROFITS,
+// BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR ANY OTHER PECUNIARY LOSS)
+// ARISING OUT OF THE  USE OF OR INABILITY  TO USE THIS SOFTWARE, EVEN IF NVIDIA HAS
+// BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
+//
+//----------------------------------------------------------------------------------
+
+#include "ShadowMap.h"
+#include <GL/glew.h>
+
+//----------------------------------------------------------------------------------
+struct ShadowMap::Vec4 {
+	Vec4() {}
+	Vec4(const PxVec3 &v, float vw = 1.0f) { x = v.x; y = v.y; z = v.z; w = vw; }
+	float x,y,z,w;
+};
+
+//----------------------------------------------------------------------------------
+struct ShadowMap::Matrix44 {
+	Vec4 operator*(const Vec4& v) const {
+		Vec4 res;
+		res.x = elems[0] * v.x + elems[4] * v.y + elems[8] * v.z + elems[12] * v.w;
+		res.y = elems[1] * v.x + elems[5] * v.y + elems[9] * v.z + elems[13] * v.w;
+		res.z = elems[2] * v.x + elems[6] * v.y + elems[10] * v.z + elems[14] * v.w;
+		res.w = elems[3] * v.x + elems[7] * v.y + elems[11] * v.z + elems[15] * v.w;
+		return res;
+	}
+	float &element(int i, int j) { return elems[i + 4*j]; }
+	void zero() { for (int i = 0; i < 16; i++) elems[i] = 0.0f; }
+	void id() { zero(); elems[0] = 1.0f; elems[5] = 1.0f; elems[10] = 1.0f; elems[15] = 1.0f; }
+
+	float elems[16];
+};
+
+//----------------------------------------------------------------------------------
+ShadowMap::ShadowMap( int w, int h, float fovi, int matOffseti, int resolution) 
+{
+	shadowOff = 1.0f;
+	shadowOff2 = 2048.0f;
+	fov = fovi;
+	cur_num_splits = 1;
+	//cur_num_splits = 3;
+
+	width = w;
+	height = h;
+	depth_size = resolution;
+	split_weight = 0.75;
+	matOffset = matOffseti;
+
+	minZAdd = 0;
+	maxZAdd = 30.0f;
+
+	init();
+}
+
+//----------------------------------------------------------------------------------
+void ShadowMap::updateFrustumPoints(Frustum &f, const PxVec3 &center, const PxVec3 &view_dir)
+{
+	PxVec3 up(0.0, 1.0, 0.0);
+	PxVec3 right = view_dir.cross(up);
+
+	PxVec3 fc = center + view_dir*f.fard;
+	PxVec3 nc = center + view_dir*f.neard;
+
+	right.normalize();
+	up = right.cross(view_dir);
+	up.normalize();
+
+	// these heights and widths are half the heights and widths of
+	// the near and far plane rectangles
+	float near_height = tanf(f.fov/2.0f) * f.neard;
+	float near_width = near_height * f.ratio;
+	float far_height = tanf(f.fov/2.0f) * f.fard;
+	float far_width = far_height * f.ratio;
+
+	f.point[0] = nc - up*near_height - right*near_width;
+	f.point[1] = nc + up*near_height - right*near_width;
+	f.point[2] = nc + up*near_height + right*near_width;
+	f.point[3] = nc - up*near_height + right*near_width;
+
+	f.point[4] = fc - up*far_height - right*far_width;
+	f.point[5] = fc + up*far_height - right*far_width;
+	f.point[6] = fc + up*far_height + right*far_width;
+	f.point[7] = fc - up*far_height + right*far_width;
+}
+
+//----------------------------------------------------------------------------------
+// updateSplitDist computes the near and far distances for every frustum slice
+// in camera eye space - that is, at what distance does a slice start and end
+void ShadowMap::updateSplitDist(Frustum f[MAX_SPLITS], float nd, float fd)
+{
+	float lambda = split_weight;
+	float ratio = fd/nd;
+	f[0].neard = nd;
+
+	for(int i=1; i<cur_num_splits; i++)
+	{
+		float si = i / (float)cur_num_splits;
+
+		f[i].neard = lambda*(nd*powf(ratio, si)) + (1-lambda)*(nd + (fd - nd)*si);
+		f[i-1].fard = f[i].neard * 1.005f;
+	}
+	f[cur_num_splits-1].fard = fd;
+}
+
+//----------------------------------------------------------------------------------
+// this function builds a projection matrix for rendering from the shadow's POV.
+// First, it computes the appropriate z-range and sets an orthogonal projection.
+// Then, it translates and scales it, so that it exactly captures the bounding box
+// of the current frustum slice
+float ShadowMap::applyCropMatrix(Frustum &f)
+{
+	float shad_proj[16];
+	float maxX = -1000.0;
+	float maxY = -1000.0;
+	float maxZ;
+	float minX =  1000.0;
+	float minY =  1000.0;
+	float minZ;
+
+	Matrix44 nv_mvp;
+	Vec4 transf;	
+	
+	// find the z-range of the current frustum as seen from the light
+	// in order to increase precision
+	glGetFloatv(GL_MODELVIEW_MATRIX, nv_mvp.elems);
+	
+	// note that only the z-component is need and thus
+	// the multiplication can be simplified
+	// transf.z = shad_modelview[2] * f.point[0].x + shad_modelview[6] * f.point[0].y + shad_modelview[10] * f.point[0].z + shad_modelview[14];
+	transf = nv_mvp * Vec4(f.point[0]);
+	minZ = transf.z;
+	maxZ = transf.z;
+	for(int i=1; i<8; i++)
+	{
+		transf = nv_mvp * Vec4(f.point[i]);
+		if(transf.z > maxZ) maxZ = transf.z;
+		if(transf.z < minZ) minZ = transf.z;
+	}
+	
+	minZ += minZAdd;
+	maxZ += maxZAdd;
+
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	// set the projection matrix with the new z-bounds
+	// note the inversion because the light looks at the neg. z axis
+	// gluPerspective(LIGHT_FOV, 1.0, maxZ, minZ); // for point lights
+	glOrtho(-1.0, 1.0, -1.0, 1.0, -maxZ, -minZ);
+	glGetFloatv(GL_PROJECTION_MATRIX, shad_proj);
+	glPushMatrix();
+	glMultMatrixf(nv_mvp.elems);
+	glGetFloatv(GL_PROJECTION_MATRIX, nv_mvp.elems);
+	glPopMatrix();
+
+	// find the extends of the frustum slice as projected in light's homogeneous coordinates
+	for(int i=0; i<8; i++)
+	{
+		transf = nv_mvp * Vec4(f.point[i]);
+
+		transf.x /= transf.w;
+		transf.y /= transf.w;
+
+		if(transf.x > maxX) maxX = transf.x;
+		if(transf.x < minX) minX = transf.x;
+		if(transf.y > maxY) maxY = transf.y;
+		if(transf.y < minY) minY = transf.y;
+	}
+
+	float scaleX = 2.0f/(maxX - minX);
+	float scaleY = 2.0f/(maxY - minY);
+	float offsetX = -0.5f*(maxX + minX)*scaleX;
+	float offsetY = -0.5f*(maxY + minY)*scaleY;
+
+	// apply a crop matrix to modify the projection matrix we got from glOrtho.
+	nv_mvp.id();
+	nv_mvp.element(0,0) = scaleX;
+	nv_mvp.element(1,1) = scaleY;
+	nv_mvp.element(0,3) = offsetX;
+	nv_mvp.element(1,3) = offsetY;
+	glLoadMatrixf(nv_mvp.elems);
+	glMultMatrixf(shad_proj);
+
+	glMatrixMode(GL_MODELVIEW);
+
+	return minZ;
+}
+
+//----------------------------------------------------------------------------------
+// here all shadow map textures and their corresponding matrices are created
+void ShadowMap::makeShadowMap(const PxVec3 &cameraPos, const PxVec3 &cameraDir, const PxVec3 &lightDir, float znear, float zfar, 
+							  void (*renderShadowCasters)())
+{
+	float shad_modelview[16];
+	glDisable(GL_TEXTURE_2D);
+
+	glMatrixMode(GL_PROJECTION);
+	glPushMatrix();
+
+	glMatrixMode(GL_MODELVIEW);
+	glPushMatrix();
+	glLoadIdentity();
+	gluLookAt(
+		cameraPos.x, cameraPos.y, cameraPos.z, 
+		cameraPos.x-lightDir.x, cameraPos.y-lightDir.y, cameraPos.z-lightDir.z,
+		-1.0, 0.0, 0.0);
+
+	glGetFloatv(GL_MODELVIEW_MATRIX, shad_modelview);
+
+	// redirect rendering to the depth texture
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, depth_fb);
+	// store the screen viewport
+	glPushAttrib(GL_VIEWPORT_BIT);
+	// and render only to the shadowmap
+	glViewport(0, 0, depth_size, depth_size);
+	// offset the geometry slightly to prevent z-fighting
+	// note that this introduces some light-leakage artifacts
+	glPolygonOffset(shadowOff, shadowOff2);
+//		cout<<"shadowOff = "<<shadowOff<<endl;
+//		cout<<"shadowOff2 = "<<shadowOff2<<endl;
+	glEnable(GL_POLYGON_OFFSET_FILL);
+
+	// compute the z-distances for each split as seen in camera space
+	updateSplitDist(f, znear, zfar);
+
+	// for all shadow maps:
+	for(int i=0; i<cur_num_splits; i++)
+	{
+		// compute the camera frustum slice boundary points in world space
+		updateFrustumPoints(f[i], cameraPos, cameraDir);
+		// adjust the view frustum of the light, so that it encloses the camera frustum slice fully.
+		// note that this function sets the projection matrix as it sees best fit
+		// minZ is just for optimization to cull trees that do not affect the shadows
+		float minZ = applyCropMatrix(f[i]);
+		// make the current depth map a rendering target
+		glFramebufferTextureLayerEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, depth_tex_ar, 0, i);
+
+		// clear the depth texture from last time
+		glClear(GL_DEPTH_BUFFER_BIT);
+
+		// draw the scene
+		(*renderShadowCasters)();
+		
+		glMatrixMode(GL_PROJECTION);
+		// store the product of all shadow matries for later
+		glMultMatrixf(shad_modelview);
+		glGetFloatv(GL_PROJECTION_MATRIX, shad_cpm[i]);
+	}
+
+	glDisable(GL_POLYGON_OFFSET_FILL);
+	glPopAttrib(); 
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+
+	glEnable(GL_TEXTURE_2D);
+
+	glMatrixMode(GL_PROJECTION);
+	glPopMatrix();
+	glMatrixMode(GL_MODELVIEW);	
+	glPopMatrix();
+}
+
+//----------------------------------------------------------------------------------
+void ShadowMap::cameraInverse(float dst[16], float src[16])
+{
+	dst[0] = src[0];
+	dst[1] = src[4];
+	dst[2] = src[8];
+	dst[3] = 0.0;
+	dst[4] = src[1];
+	dst[5] = src[5];
+	dst[6]  = src[9];
+	dst[7] = 0.0;
+	dst[8] = src[2];
+	dst[9] = src[6];
+	dst[10] = src[10];
+	dst[11] = 0.0;
+	dst[12] = -(src[12] * src[0]) - (src[13] * src[1]) - (src[14] * src[2]);
+	dst[13] = -(src[12] * src[4]) - (src[13] * src[5]) - (src[14] * src[6]);
+	dst[14] = -(src[12] * src[8]) - (src[13] * src[9]) - (src[14] * src[10]);
+	dst[15] = 1.0;
+}
+
+//----------------------------------------------------------------------------------
+void ShadowMap::doneRender() 
+{
+	// Unbind texture
+	for (int i = 0; i < 8; i++) {
+		glActiveTexture(GL_TEXTURE0 + i);
+		glMatrixMode(GL_TEXTURE);
+		glLoadIdentity();
+	}
+	glActiveTexture(GL_TEXTURE0);
+}
+
+//----------------------------------------------------------------------------------
+void ShadowMap::prepareForRender(float* cam_modelview, float* cam_proj)
+{
+	float cam_inverse_modelview[16];
+	const float bias[16] = {	0.5, 0.0, 0.0, 0.0, 
+								0.0, 0.5, 0.0, 0.0,
+								0.0, 0.0, 0.5, 0.0,
+								0.5, 0.5f, 0.5, 1.0	};
+
+	// update the camera, so that the user can have a free look
+	cameraInverse(cam_inverse_modelview, cam_modelview);
+
+	glActiveTexture(GL_TEXTURE0);
+
+	for(int i=cur_num_splits; i<MAX_SPLITS; i++)
+		far_bound[i] = 0;
+
+	// for every active split
+	for(int i=0; i<cur_num_splits; i++)
+	{
+		// f[i].fard is originally in eye space - tell's us how far we can see.
+		// Here we compute it in camera homogeneous coordinates. Basically, we calculate
+		// cam_proj * (0, 0, f[i].fard, 1)^t and then normalize to [0; 1]
+		far_bound[i] = 0.5f*(-f[i].fard*cam_proj[10]+cam_proj[14])/f[i].fard + 0.5f;
+
+		// compute a matrix that transforms from camera eye space to light clip space
+		// and pass it to the shader through the OpenGL texture matrices, since we
+		// don't use them now
+		glActiveTexture(GL_TEXTURE0 + (GLenum)i + matOffset);
+		glMatrixMode(GL_TEXTURE);
+		glLoadMatrixf(bias);
+		glMultMatrixf(shad_cpm[i]);
+		// multiply the light's (bias*crop*proj*modelview) by the inverse camera modelview
+		// so that we can transform a pixel as seen from the camera
+		glMultMatrixf(cam_inverse_modelview);
+	}
+
+	glActiveTexture(GL_TEXTURE0);
+}
+
+//----------------------------------------------------------------------------------
+void ShadowMap::init()
+{
+	//glClearColor(0.8f, 0.8f , 0.9f, 1.0);
+	//glEnable(GL_CULL_FACE);
+	glEnable(GL_DEPTH_TEST);
+	glEnable(GL_LIGHTING);
+	glEnable(GL_LIGHT0);
+
+
+	glGenFramebuffersEXT(1, &depth_fb);
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, depth_fb);
+	glDrawBuffer(GL_NONE);
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+
+	glGenTextures(1, &depth_tex_ar);
+
+	glBindTexture(GL_TEXTURE_2D_ARRAY_EXT, depth_tex_ar);
+	glTexImage3D(GL_TEXTURE_2D_ARRAY_EXT, 0, GL_DEPTH_COMPONENT32, depth_size, depth_size, MAX_SPLITS, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
+	glTexParameteri(GL_TEXTURE_2D_ARRAY_EXT, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D_ARRAY_EXT, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D_ARRAY_EXT, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D_ARRAY_EXT, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D_ARRAY_EXT, GL_TEXTURE_COMPARE_FUNC, GL_LEQUAL);
+
+	for(int i=0; i<MAX_SPLITS; i++)
+	{
+		// note that fov is in radians here and in OpenGL it is in degrees.
+		// the 0.2f factor is important because we might get artifacts at
+		// the screen borders.
+		f[i].fov = fov/57.2957795f + 0.2f;
+		f[i].ratio = (float)width/(float)height;
+	}
+
+}
+
-- 
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