Render portal gun with smaller near clip plane.

src/scene/camera.c

@@ -140,6 +140,26 @@ error:
     return 0;
 }
 
+void cameraModifyProjectionViewForPortalGun(struct Camera* camera, struct RenderState* renderState, float newNearPlane, float aspectRatio)
+{
+    Mtx* portalGunProjectionView = renderStateRequestMatrices(renderState, 1);
+    if(!portalGunProjectionView)
+        return;
+    
+    struct Camera portalCam = *camera;
+    portalCam.nearPlane = newNearPlane;
+    float view[4][4];
+    float projectionView[4][4];
+    unsigned short perspectiveNormalize;
+    cameraBuildProjectionMatrix(&portalCam, projectionView, &perspectiveNormalize, aspectRatio);
+    cameraBuildViewMatrix(&portalCam, view);
+    guMtxCatF(view, projectionView, projectionView);
+    
+    guMtxF2L(projectionView, portalGunProjectionView);
+    gSPMatrix(renderState->dl++, osVirtualToPhysical(portalGunProjectionView), G_MTX_PROJECTION | G_MTX_LOAD | G_MTX_NOPUSH);
+    gSPPerspNormalize(renderState->dl++, perspectiveNormalize);
+}
+
 int cameraApplyMatrices(struct RenderState* renderState, struct CameraMatrixInfo* matrixInfo) {
     Mtx* modelMatrix = renderStateRequestMatrices(renderState, 1);
     

src/scene/camera.h

@@ -41,6 +41,7 @@ void cameraInit(struct Camera* camera, float fov, float near, float far);
 void cameraBuildViewMatrix(struct Camera* camera, float matrix[4][4]);
 void cameraBuildProjectionMatrix(struct Camera* camera, float matrix[4][4], u16* perspectiveNorm, float aspectRatio);
 int cameraSetupMatrices(struct Camera* camera, struct RenderState* renderState, float aspectRatio, Vp* viewport, int extractClippingPlanes, struct CameraMatrixInfo* output);
+void cameraModifyProjectionViewForPortalGun(struct Camera* camera, struct RenderState* renderState, float newNearPlane, float aspectRatio);
 
 int cameraApplyMatrices(struct RenderState* renderState, struct CameraMatrixInfo* matrixInfo);
 

src/scene/render_plan.h

@@ -6,6 +6,7 @@
 
 #define DEFAULT_FAR_PLANE       30.0f
 #define DEFAULT_NEAR_PLANE      0.125f
+#define PORTAL_GUN_NEAR_PLANE   0.05f
 
 #define MAX_PORTAL_STEPS    6
 

src/scene/scene.c

@@ -299,6 +299,7 @@ void sceneRender(struct Scene* scene, struct RenderState* renderState, struct Gr
     renderPlanBuild(&renderPlan, scene, renderState);
     renderPlanExecute(&renderPlan, scene, staticMatrices, renderState);
 
+    cameraModifyProjectionViewForPortalGun(&scene->camera, renderState, PORTAL_GUN_NEAR_PLANE * SCENE_SCALE, renderPlan.stageProps[0].aspectRatio);
     portalGunRenderReal(&scene->portalGun, renderState);
 
     gDPPipeSync(renderState->dl++);