eliminate two calls to qglGetDoublev that possibly slow down rendering by doing a...

Infinite far clip already used this method, as there is no GL helper for using the infinite far clip matrix.

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@8242 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/gl_backend.c b/gl_backend.c
index 6b7f99981c39f176c0868b82e625abe784266ca1..b6425f707ad963e379fa1ea9658e4ea9cc062b1d 100644 (file)
--- a/gl_backend.c
+++ b/gl_backend.c
@@ -303,6 +303,29 @@ void GL_SetupView_Orientation_FromEntity(const matrix4x4_t *matrix)
        R_Mesh_Matrix(&tempmatrix);
 }
 
+static void GL_BuildFrustum(double m[16], double left, double right, double bottom, double top, double nearVal, double farVal)
+{
+       m[0]  = 2 * nearVal / (right - left);
+       m[1]  = 0;
+       m[2]  = 0;
+       m[3]  = 0;
+         
+       m[4]  = 0;
+       m[5]  = 2 * nearVal / (top - bottom);
+       m[6]  = 0;
+       m[7]  = 0;
+         
+       m[8]  = (right + left) / (right - left);
+       m[9]  = (top + bottom) / (top - bottom);
+       m[10] = - (farVal + nearVal) / (farVal - nearVal);
+       m[11] = -1;
+
+       m[12] = 0;
+       m[13] = 0;
+       m[14] = - 2 * farVal * nearVal / (farVal - nearVal);
+       m[15] = 0;
+}
+
 void GL_SetupView_Mode_Perspective (double frustumx, double frustumy, double zNear, double zFar)
 {
        double m[16];
@@ -310,10 +333,18 @@ void GL_SetupView_Mode_Perspective (double frustumx, double frustumy, double zNe
        // set up viewpoint
        CHECKGLERROR
        qglMatrixMode(GL_PROJECTION);CHECKGLERROR
-       qglLoadIdentity();CHECKGLERROR
        // set view pyramid
+#if 1
+       // avoid glGetDoublev whenever possible, it may stall the render pipeline
+       // in the tested cases (nvidia) no measurable fps difference, but it sure
+       // makes a difference over a network line with GLX
+       GL_BuildFrustum(m, -frustumx * zNear, frustumx * zNear, -frustumy * zNear, frustumy * zNear, zNear, zFar);
+       qglLoadMatrixd(m);CHECKGLERROR
+#else
+       qglLoadIdentity();CHECKGLERROR
        qglFrustum(-frustumx * zNear, frustumx * zNear, -frustumy * zNear, frustumy * zNear, zNear, zFar);CHECKGLERROR
        qglGetDoublev(GL_PROJECTION_MATRIX, m);CHECKGLERROR
+#endif
        Matrix4x4_FromArrayDoubleGL(&backend_projectmatrix, m);
        qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
        GL_SetupView_Orientation_Identity();
@@ -353,6 +384,29 @@ void GL_SetupView_Mode_PerspectiveInfiniteFarClip (double frustumx, double frust
        Matrix4x4_FromArrayDoubleGL(&backend_projectmatrix, m);
 }
 
+static void GL_BuildOrtho(double m[16], double left, double right, double bottom, double top, double near, double far)
+{
+       m[0]  = 2/(right - left);
+       m[1]  = 0;
+       m[2]  = 0;
+       m[3]  = 0;
+         
+       m[4]  = 0;
+       m[5]  = 2/(top - bottom);
+       m[6]  = 0;
+       m[7]  = 0;
+         
+       m[8]  = 0;
+       m[9]  = 0;
+       m[10] = -2/(far - near);
+       m[11] = 0;
+
+       m[12] = - (right + left)/(right - left);
+       m[13] = - (top + bottom)/(top - bottom);
+       m[14] = - (far + near)/(far - near);
+       m[15] = 1;
+}
+
 void GL_SetupView_Mode_Ortho (double x1, double y1, double x2, double y2, double zNear, double zFar)
 {
        double m[16];
@@ -360,9 +414,17 @@ void GL_SetupView_Mode_Ortho (double x1, double y1, double x2, double y2, double
        // set up viewpoint
        CHECKGLERROR
        qglMatrixMode(GL_PROJECTION);CHECKGLERROR
+#if 1
+       // avoid glGetDoublev whenever possible, it may stall the render pipeline
+       // in the tested cases (nvidia) no measurable fps difference, but it sure
+       // makes a difference over a network line with GLX
+       GL_BuildOrtho(m, x1, x2, y2, y1, zNear, zFar);
+       qglLoadMatrixd(m);CHECKGLERROR
+#else
        qglLoadIdentity();CHECKGLERROR
        qglOrtho(x1, x2, y2, y1, zNear, zFar);CHECKGLERROR
        qglGetDoublev(GL_PROJECTION_MATRIX, m);CHECKGLERROR
+#endif
        Matrix4x4_FromArrayDoubleGL(&backend_projectmatrix, m);
        qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
        GL_SetupView_Orientation_Identity();