Calculate initial C0 curves based off of the original code points.

Signed-off-by: Ian Romanick <idr@freedesktop.org>
Signed-off-by: Kenneth Graunke <kenneth@freedesktop.org>

1 files changed, 21 insertions, 15 deletions

diff --git a/src/main.cpp b/src/main.cpp
index bdd9393..b2d5091 100755
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -50,21 +50,7 @@ static const GLUvec4 linear_control_points[] = {
 /**
  * Basic C0 cameara control curves that hit the points in linear_control_points
  */
-static const bezier_curve camera_curves[] = {
-	bezier_curve(linear_control_points[0],          // start point
-		     GLUvec4(10.0f, 3.5f, 20.0f, 0.0f), // control
-		     GLUvec4(15.0f, 3.5f, 5.0f, 0.0f),  // control
-		     linear_control_points[1]),         // end point
-	bezier_curve(linear_control_points[1],
-		     GLUvec4(15.0f, 1.5f, -20.0f, 0.0f),
-		     GLUvec4(-10.0f, 1.5f, -35.0f, 0.0f),
-		     linear_control_points[2]),
-	bezier_curve(linear_control_points[2],
-		     GLUvec4(-40.0f, -0.5f, -10.0f, 0.0f),
-		     GLUvec4(-25.0f, -0.5f, 12.0f, 0.0f),
-		     linear_control_points[0]),
-
-};
+static bezier_curve camera_curves[ELEMENTS_OF(linear_control_points)];
 
 /**
  * Control curves from camera_curves "fixed" to be G1.
@@ -300,6 +286,25 @@ load_and_compile_program_code(const char *shader)
 
 
 /**
+ * Create initial bezier curves based on the given linear control points that
+ * the camera must hit.  These have C0 continuity.
+ */
+void
+make_initial_curves()
+{
+	for (unsigned i = 0; i < 3; i++) {
+		unsigned next = (i + 1) % 3;
+		GLUvec4 a = lerp(linear_control_points[i],
+				 linear_control_points[next], 1. / 3.) * 2.;
+		GLUvec4 b = lerp(linear_control_points[i],
+				 linear_control_points[next], 2. / 3.) * 2.;
+		camera_curves[i] = bezier_curve(linear_control_points[i], a, b,
+						linear_control_points[next]);
+	}
+}
+
+
+/**
  * Modify the control points of two C0 curves to make the G1
  *
  * The curves generated by this function will only modify the neighboring
@@ -394,6 +399,7 @@ Init(void)
 	       "    c: Re-load and compile shader program code.\n"
 	       "  ESC: Exit program.\n");
 
+	make_initial_curves();
 	for (int i = 0; i < 3; i++) {
 		camera_curves_G1[i] = camera_curves[i];
 		camera_curves_C1[i] = camera_curves[i];