From 966fe28c59f59fc8be795c8215b9352435982445 Mon Sep 17 00:00:00 2001 From: Aki Date: Thu, 30 Sep 2021 16:46:36 +0200 Subject: Merged nGenEx and Parser into Stars45 --- Stars45/Projector.cpp | 494 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 494 insertions(+) create mode 100644 Stars45/Projector.cpp (limited to 'Stars45/Projector.cpp') diff --git a/Stars45/Projector.cpp b/Stars45/Projector.cpp new file mode 100644 index 0000000..6881682 --- /dev/null +++ b/Stars45/Projector.cpp @@ -0,0 +1,494 @@ +/* Starshatter OpenSource Distribution + Copyright (c) 1997-2004, Destroyer Studios LLC. + All Rights Reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. + * Neither the name "Destroyer Studios" nor the names of its contributors + may be used to endorse or promote products derived from this software + without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + POSSIBILITY OF SUCH DAMAGE. + + SUBSYSTEM: nGenEx.lib + FILE: Projector.cpp + AUTHOR: John DiCamillo + + + OVERVIEW + ======== + 3D Projection Camera class +*/ + +#include "MemDebug.h" +#include "Projector.h" + +// +--------------------------------------------------------------------+ + +static const float CLIP_PLANE_EPSILON = 0.0001f; +static const double Z_NEAR = 1.0; + +void Print(const char* fmt, ...); + +// +--------------------------------------------------------------------+ + +static Camera emergency_cam; + +// +--------------------------------------------------------------------+ + +Projector::Projector(Window* window, Camera* cam) +: camera(cam), infinite(0), depth_scale(1.0f), orthogonal(false), field_of_view(2) +{ + if (!camera) + camera = &emergency_cam; + + UseWindow(window); +} + +Projector::~Projector() +{ } + +// +--------------------------------------------------------------------+ + +void +Projector::UseCamera(Camera* cam) +{ + if (cam) + camera = cam; + else + camera = &emergency_cam; +} + +void +Projector::UseWindow(Window* win) +{ + Rect r = win->GetRect(); + width = r.w; + height = r.h; + + xcenter = (width / 2.0); + ycenter = (height / 2.0); + + xclip0 = 0.0f; + xclip1 = (float) width-0.5f; + yclip0 = 0.0f; + yclip1 = (float) height-0.5f; + + SetFieldOfView(field_of_view); +} + +void +Projector::SetFieldOfView(double fov) +{ + field_of_view = fov; + + xscreenscale = width / fov; + yscreenscale = height / fov; + + maxscale = max(xscreenscale, yscreenscale); + + xangle = atan(2.0/fov * maxscale/xscreenscale); + yangle = atan(2.0/fov * maxscale/yscreenscale); +} + +double +Projector::GetFieldOfView() const +{ + return field_of_view; +} + +void +Projector::SetDepthScale(float scale) +{ + depth_scale = scale; +} + +double +Projector::GetDepthScale() const +{ + return depth_scale; +} + +int +Projector::SetInfinite(int i) +{ + int old = infinite; + infinite = i; + return old; +} + +// +--------------------------------------------------------------------+ + +void +Projector::StartFrame() +{ + SetUpFrustum(); + SetWorldSpace(); +} + +// +--------------------------------------------------------------------+ +// Transform a point from worldspace to viewspace. +// +--------------------------------------------------------------------+ + +void +Projector::Transform(Vec3& vec) const +{ + Vec3 tvert = vec; + + // Translate into a viewpoint-relative coordinate + if (!infinite) + tvert -= camera->Pos(); + + // old method: + vec.x = (tvert * camera->vrt()); + vec.y = (tvert * camera->vup()); + vec.z = (tvert * camera->vpn()); + + // Rotate into the view orientation + // vec = tvert * camera->Orientation(); +} + +// +--------------------------------------------------------------------+ +// Transform a point from worldspace to viewspace. +// +--------------------------------------------------------------------+ + +void +Projector::Transform(Point& point) const +{ + Point tvert = point; + + // Translate into a viewpoint-relative coordinate + if (!infinite) + tvert -= camera->Pos(); + + // old method: + point.x = (tvert * camera->vrt()); + point.y = (tvert * camera->vup()); + point.z = (tvert * camera->vpn()); + + // Rotate into the view orientation + // point = tvert * camera->Orientation(); +} + +// +--------------------------------------------------------------------+ +// APPARENT RADIUS OF PROJECTED OBJECT +// Project a viewspace point into screen coordinates. +// Use projected Z to determine apparent radius of object. +// +--------------------------------------------------------------------+ + +float +Projector::ProjectRadius(const Vec3& v, float radius) const +{ + return (float) fabs((radius * maxscale) / v.z); +} + +// +--------------------------------------------------------------------+ +// IN PLACE PROJECTION OF POINT +// Project a viewspace point into screen coordinates. +// Note that the y axis goes up in worldspace and viewspace, but +// goes down in screenspace. +// +--------------------------------------------------------------------+ + +void +Projector::Project(Vec3& v, bool clamp) const +{ + double zrecip; + + if (orthogonal) { + double scale = field_of_view/2; + v.x = (float) (xcenter + scale * v.x); + v.y = (float) (height - (ycenter + scale * v.y)); + v.z = (float) (0.0f); + } + + else { + //zrecip = 2 * (1.0e5 / (1.0e5-1)) / v.z; + //zrecip = 2 * 0.97 / v.z; -- what the heck was this version used for? + + zrecip = 2 / v.z; + v.x = (float) (xcenter + maxscale * v.x * zrecip); + v.y = (float) (height - (ycenter + maxscale * v.y * zrecip)); + v.z = (float) (1 - zrecip); + } + + // clamp the point to the viewport: + if (clamp) { + if (v.x < xclip0) v.x = xclip0; + if (v.x > xclip1) v.x = xclip1; + if (v.y < yclip0) v.y = yclip0; + if (v.y > yclip1) v.y = yclip1; + } +} + +// +--------------------------------------------------------------------+ +// IN PLACE PROJECTION OF POINT +// Project a viewspace point into screen coordinates. +// Note that the y axis goes up in worldspace and viewspace, but +// goes down in screenspace. +// +--------------------------------------------------------------------+ + +void +Projector::Project(Point& v, bool clamp) const +{ + double zrecip; + + if (orthogonal) { + double scale = field_of_view/2; + v.x = (xcenter + scale * v.x); + v.y = (height - (ycenter + scale * v.y)); + v.z = 0; + } + + else { + zrecip = 1 / v.z; + v.x = (xcenter + 2 * maxscale * v.x * zrecip); + v.y = (height - (ycenter + 2 * maxscale * v.y * zrecip)); + v.z = (1 - zrecip); + } + + // clamp the point to the viewport: + if (clamp) { + if (v.x < xclip0) v.x = xclip0; + if (v.x > xclip1) v.x = xclip1; + if (v.y < yclip0) v.y = yclip0; + if (v.y > yclip1) v.y = yclip1; + } +} + +// +--------------------------------------------------------------------+ +// IN PLACE UN-PROJECTION OF POINT +// Convert a point in screen coordinates back to viewspace. +// Note that the y axis goes up in worldspace and viewspace, but +// goes down in screenspace. +// +--------------------------------------------------------------------+ + +void +Projector::Unproject(Point& v) const +{ + double zrecip = 1 / v.z; + + /*** + * forward projection: +v.x = (xcenter + maxscale * v.x * zrecip); +v.y = (height - (ycenter + maxscale * v.y * zrecip)); +v.z = (1 - zrecip); +***/ + + v.x = ( v.x - xcenter) / (maxscale * zrecip); + v.y = (height - v.y - ycenter) / (maxscale * zrecip); +} + +// +--------------------------------------------------------------------+ +// IN PLACE PROJECTION OF RECTANGLE (FOR SPRITES) +// Project a viewspace point into screen coordinates. +// Note that the y axis goes up in worldspace and viewspace, but +// goes down in screenspace. +// +--------------------------------------------------------------------+ + +void +Projector::ProjectRect(Point& v, double& w, double& h) const +{ + double zrecip; + + if (orthogonal) { + double scale = field_of_view/2; + v.x = (xcenter + scale * v.x); + v.y = (height - (ycenter + scale * v.y)); + v.z = 0; + } + + else { + zrecip = 1 / v.z; + v.x = (xcenter + 2 * maxscale * v.x * zrecip); + v.y = (height - (ycenter + 2 * maxscale * v.y * zrecip)); + v.z = (1 - Z_NEAR*zrecip); + + w *= maxscale * zrecip; + h *= maxscale * zrecip; + } +} + +// +--------------------------------------------------------------------+ +// Set up a clip plane with the specified normal. +// +--------------------------------------------------------------------+ + +void +Projector::SetWorldspaceClipPlane(Vec3& normal, Plane& plane) +{ + // Rotate the plane normal into worldspace + ViewToWorld(normal, plane.normal); + plane.distance = (float) (camera->Pos() * plane.normal + CLIP_PLANE_EPSILON); +} + +// +--------------------------------------------------------------------+ +// Set up the planes of the frustum, in worldspace coordinates. +// +--------------------------------------------------------------------+ + +void +Projector::SetUpFrustum() +{ + double angle, s, c; + Vec3 normal; + + angle = XAngle(); + s = sin(angle); + c = cos(angle); + + // Left clip plane + normal.x = (float) s; + normal.y = (float) 0; + normal.z = (float) c; + view_planes[0].normal = normal; + view_planes[0].distance = CLIP_PLANE_EPSILON; + SetWorldspaceClipPlane(normal, world_planes[0]); + + // Right clip plane + normal.x = (float) -s; + view_planes[1].normal = normal; + view_planes[1].distance = CLIP_PLANE_EPSILON; + SetWorldspaceClipPlane(normal, world_planes[1]); + + angle = YAngle(); + s = sin(angle); + c = cos(angle); + + // Bottom clip plane + normal.x = (float) 0; + normal.y = (float) s; + normal.z = (float) c; + view_planes[2].normal = normal; + view_planes[2].distance = CLIP_PLANE_EPSILON; + SetWorldspaceClipPlane(normal, world_planes[2]); + + // Top clip plane + normal.y = (float) -s; + view_planes[3].normal = normal; + view_planes[3].distance = CLIP_PLANE_EPSILON; + SetWorldspaceClipPlane(normal, world_planes[3]); +} + +// +--------------------------------------------------------------------+ +// Clip the point against the frustum and return 1 if partially inside +// Return 2 if completely inside +// +--------------------------------------------------------------------+ + +int +Projector::IsVisible(const Vec3& v, float radius) const +{ + int visible = 1; + int complete = 1; + + Plane* plane = (Plane*) frustum_planes; + if (infinite) { + complete = 0; + + for (int i = 0; visible && (i < NUM_FRUSTUM_PLANES); i++) { + visible = ((v * plane->normal) >= CLIP_PLANE_EPSILON); + plane++; + } + } + else { + for (int i = 0; visible && (i < NUM_FRUSTUM_PLANES); i++) { + float dot = v * plane->normal; + visible = ((dot + radius) >= plane->distance); + complete = complete && ((dot - radius) >= plane->distance); + plane++; + } + } + + return visible + complete; +} + +// +--------------------------------------------------------------------+ +// Clip the bouding point against the frustum and return non zero +// if at least partially inside. This version is not terribly +// efficient as it checks all eight box corners rather than just +// the minimum two. +// +--------------------------------------------------------------------+ + +int +Projector::IsBoxVisible(const Point* p) const +{ + int i, j, outside = 0; + + // if all eight corners are outside of the same + // frustrum plane, then the box is not visible + Plane* plane = (Plane*) frustum_planes; + + if (infinite) { + for (i = 0; !outside && (i < NUM_FRUSTUM_PLANES); i++) { + for (j = 0; j < 8; j++) + outside += (p[j] * plane->normal) < CLIP_PLANE_EPSILON; + + if (outside < 8) + outside = 0; + + plane++; + } + } + else { + for (i = 0; !outside && (i < NUM_FRUSTUM_PLANES); i++) { + for (j = 0; j < 8; j++) + outside += (p[j] * plane->normal) < plane->distance; + + if (outside < 8) + outside = 0; + + plane++; + } + } + + // if not outside, then the box is visible + return !outside; +} + +// +--------------------------------------------------------------------+ + +float +Projector::ApparentRadius(const Vec3& v, float radius) const +{ + Vec3 vloc = v; + + Transform(vloc); // transform in place + return ProjectRadius(vloc, radius); +} + + +// +--------------------------------------------------------------------+ +// Rotate a vector from viewspace to worldspace. +// +--------------------------------------------------------------------+ + +void +Projector::ViewToWorld(Point& pin, Point& pout) +{ + // Rotate into the world orientation + pout.x = pin.x * camera->vrt().x + pin.y * camera->vup().x + pin.z * camera->vpn().x; + pout.y = pin.x * camera->vrt().y + pin.y * camera->vup().y + pin.z * camera->vpn().y; + pout.z = pin.x * camera->vrt().z + pin.y * camera->vup().z + pin.z * camera->vpn().z; +} + +void +Projector::ViewToWorld(Vec3& vin, Vec3& vout) +{ + // Rotate into the world orientation + vout.x = (float) (vin.x * camera->vrt().x + vin.y * camera->vup().x + vin.z * camera->vpn().x); + vout.y = (float) (vin.x * camera->vrt().y + vin.y * camera->vup().y + vin.z * camera->vpn().y); + vout.z = (float) (vin.x * camera->vrt().z + vin.y * camera->vup().z + vin.z * camera->vpn().z); +} + -- cgit v1.1