Added frustum plane extraction and sphere culling code.

Change-Id: I9d55baecddc962f8973f0269f2f9977f1d4ce008

2 files changed, 89 insertions, 2 deletions

diff --git a/libs/rs/scriptc/rs_core.rsh b/libs/rs/scriptc/rs_core.rsh
index aa9aebc..0bfb3b9 100644
--- a/libs/rs/scriptc/rs_core.rsh
+++ b/libs/rs/scriptc/rs_core.rsh
@@ -767,6 +767,92 @@ static void rsQuaternionGetMatrixUnit(rs_matrix4x4 *m, const rs_quaternion *q) {
     m->m[15] = 1.0f;
 }
 
+/////////////////////////////////////////////////////
+// utility funcs
+/////////////////////////////////////////////////////
+void __attribute__((overloadable))
+rsExtractFrustumPlanes(const rs_matrix4x4 *modelViewProj,
+                         float4 *left, float4 *right,
+                         float4 *top, float4 *bottom,
+                         float4 *near, float4 *far) {
+    // x y z w = a b c d in the plane equation
+    left->x = modelViewProj->m[3] + modelViewProj->m[0];
+    left->y = modelViewProj->m[7] + modelViewProj->m[4];
+    left->z = modelViewProj->m[11] + modelViewProj->m[8];
+    left->w = modelViewProj->m[15] + modelViewProj->m[12];
+
+    right->x = modelViewProj->m[3] - modelViewProj->m[0];
+    right->y = modelViewProj->m[7] - modelViewProj->m[4];
+    right->z = modelViewProj->m[11] - modelViewProj->m[8];
+    right->w = modelViewProj->m[15] - modelViewProj->m[12];
+
+    top->x = modelViewProj->m[3] - modelViewProj->m[1];
+    top->y = modelViewProj->m[7] - modelViewProj->m[5];
+    top->z = modelViewProj->m[11] - modelViewProj->m[9];
+    top->w = modelViewProj->m[15] - modelViewProj->m[13];
+
+    bottom->x = modelViewProj->m[3] + modelViewProj->m[1];
+    bottom->y = modelViewProj->m[7] + modelViewProj->m[5];
+    bottom->z = modelViewProj->m[11] + modelViewProj->m[9];
+    bottom->w = modelViewProj->m[15] + modelViewProj->m[13];
+
+    near->x = modelViewProj->m[3] + modelViewProj->m[2];
+    near->y = modelViewProj->m[7] + modelViewProj->m[6];
+    near->z = modelViewProj->m[11] + modelViewProj->m[10];
+    near->w = modelViewProj->m[15] + modelViewProj->m[14];
+
+    far->x = modelViewProj->m[3] - modelViewProj->m[2];
+    far->y = modelViewProj->m[7] - modelViewProj->m[6];
+    far->z = modelViewProj->m[11] - modelViewProj->m[10];
+    far->w = modelViewProj->m[15] - modelViewProj->m[14];
+
+    float len = length(left->xyz);
+    *left /= len;
+    len = length(right->xyz);
+    *right /= len;
+    len = length(top->xyz);
+    *top /= len;
+    len = length(bottom->xyz);
+    *bottom /= len;
+    len = length(near->xyz);
+    *near /= len;
+    len = length(far->xyz);
+    *far /= len;
+}
+
+bool __attribute__((overloadable))
+rsIsSphereInFrustum(float4 *sphere,
+                      float4 *left, float4 *right,
+                      float4 *top, float4 *bottom,
+                      float4 *near, float4 *far) {
+
+    float distToCenter = dot(left->xyz, sphere->xyz) + left->w;
+    if(distToCenter < -sphere->w) {
+        return false;
+    }
+    distToCenter = dot(right->xyz, sphere->xyz) + right->w;
+    if(distToCenter < -sphere->w) {
+        return false;
+    }
+    distToCenter = dot(top->xyz, sphere->xyz) + top->w;
+    if(distToCenter < -sphere->w) {
+        return false;
+    }
+    distToCenter = dot(bottom->xyz, sphere->xyz) + bottom->w;
+    if(distToCenter < -sphere->w) {
+        return false;
+    }
+    distToCenter = dot(near->xyz, sphere->xyz) + near->w;
+    if(distToCenter < -sphere->w) {
+        return false;
+    }
+    distToCenter = dot(far->xyz, sphere->xyz) + far->w;
+    if(distToCenter < -sphere->w) {
+        return false;
+    }
+    return true;
+}
+
 
 /////////////////////////////////////////////////////
 // int ops
diff --git a/libs/rs/scriptc/rs_graphics.rsh b/libs/rs/scriptc/rs_graphics.rsh
index 63bd9d7..c0b2d2d 100644
--- a/libs/rs/scriptc/rs_graphics.rsh
+++ b/libs/rs/scriptc/rs_graphics.rsh
@@ -27,6 +27,9 @@ extern void __attribute__((overloadable))
     rsgProgramVertexLoadTextureMatrix(const rs_matrix4x4 *);
 
 extern void __attribute__((overloadable))
+    rsgProgramVertexGetProjectionMatrix(rs_matrix4x4 *);
+
+extern void __attribute__((overloadable))
     rsgProgramFragmentConstantColor(rs_program_fragment, float, float, float, float);
 
 extern uint __attribute__((overloadable))
@@ -92,8 +95,6 @@ rsgMeshComputeBoundingBox(rs_mesh mesh, float3 *bBoxMin, float3 *bBoxMax) {
     bBoxMax->z = z2;
 }
 
-
-
 ///////////////////////////////////////////////////////
 // misc