[vlc-commits] vout/opengl: fix flipped and transposed orientation

[Adrien Maglo]

vlc | branch: master | Adrien Maglo <magsoft at videolan.org> | Mon Dec 19 10:54:48 2016 +0100| [80bcbe8d5ff2623ff0dc9003d68e9a9e3d071688] | committer: Thomas Guillem

vout/opengl: fix flipped and transposed orientation

Now that GL_CULL_FACE is enabled (for 360 videos), it's not possible to flip or
transpose the video by touching the vertex positions. The orientation matrix
must now be applied on the textures coordinates.

Signed-off-by: Thomas Guillem <thomas at gllm.fr>

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=80bcbe8d5ff2623ff0dc9003d68e9a9e3d071688
---

 modules/video_output/opengl/vout_helper.c | 58 ++++++++++++++++---------------
 1 file changed, 30 insertions(+), 28 deletions(-)

diff --git a/modules/video_output/opengl/vout_helper.c b/modules/video_output/opengl/vout_helper.c
index e010ee3..017c335 100644
--- a/modules/video_output/opengl/vout_helper.c
+++ b/modules/video_output/opengl/vout_helper.c
@@ -144,10 +144,10 @@ static void BuildVertexShader(vout_display_opengl_t *vgl,
         "uniform mat4 ZRotMatrix;"
         "uniform mat4 ZoomMatrix;"
         "void main() {"
-        " TexCoord0 = MultiTexCoord0;"
-        " TexCoord1 = MultiTexCoord1;"
-        " TexCoord2 = MultiTexCoord2;"
-        " gl_Position = ProjectionMatrix * OrientationMatrix * ZoomMatrix * ZRotMatrix * XRotMatrix * YRotMatrix * vec4(VertexPosition, 1.0);"
+        " TexCoord0 = OrientationMatrix * MultiTexCoord0;"
+        " TexCoord1 = OrientationMatrix * MultiTexCoord1;"
+        " TexCoord2 = OrientationMatrix * MultiTexCoord2;"
+        " gl_Position = ProjectionMatrix * ZoomMatrix * ZRotMatrix * XRotMatrix * YRotMatrix * vec4(VertexPosition, 1.0);"
         "}";
 
     *shader = vgl->api.CreateShader(GL_VERTEX_SHADER);
@@ -803,55 +803,57 @@ static void orientationTransformMatrix(GLfloat matrix[static 16],
     const int k_sin_pi_2 = 1;
     const int k_sin_n_pi_2 = -1;
 
-    bool rotate = false;
-    int cos = 0, sin = 0;
-
     switch (orientation) {
 
         case ORIENT_ROTATED_90:
-            cos = k_cos_pi_2;
-            sin = k_sin_pi_2;
-            rotate = true;
+            matrix[0 * 4 + 0] = k_cos_pi_2;
+            matrix[0 * 4 + 1] = -k_sin_pi_2;
+            matrix[1 * 4 + 0] = k_sin_pi_2;
+            matrix[1 * 4 + 1] = k_cos_pi_2;
+            matrix[3 * 4 + 1] = 1;
             break;
         case ORIENT_ROTATED_180:
-            cos = k_cos_pi;
-            sin = k_sin_pi;
-            rotate = true;
+            matrix[0 * 4 + 0] = k_cos_pi;
+            matrix[0 * 4 + 1] = -k_sin_pi;
+            matrix[1 * 4 + 0] = k_sin_pi;
+            matrix[1 * 4 + 1] = k_cos_pi;
+            matrix[3 * 4 + 0] = 1;
+            matrix[3 * 4 + 1] = 1;
             break;
         case ORIENT_ROTATED_270:
-            cos = k_cos_n_pi_2;
-            sin = k_sin_n_pi_2;
-            rotate = true;
+            matrix[0 * 4 + 0] = k_cos_n_pi_2;
+            matrix[0 * 4 + 1] = -k_sin_n_pi_2;
+            matrix[1 * 4 + 0] = k_sin_n_pi_2;
+            matrix[1 * 4 + 1] = k_cos_n_pi_2;
+            matrix[3 * 4 + 0] = 1;
             break;
         case ORIENT_HFLIPPED:
             matrix[0 * 4 + 0] = -1;
+            matrix[3 * 4 + 0] = 1;
             break;
         case ORIENT_VFLIPPED:
             matrix[1 * 4 + 1] = -1;
+            matrix[3 * 4 + 1] = 1;
             break;
         case ORIENT_TRANSPOSED:
             matrix[0 * 4 + 0] = 0;
-            matrix[0 * 4 + 1] = -1;
-            matrix[1 * 4 + 0] = -1;
             matrix[1 * 4 + 1] = 0;
+            matrix[2 * 4 + 2] = -1;
+            matrix[0 * 4 + 1] = 1;
+            matrix[1 * 4 + 0] = 1;
             break;
         case ORIENT_ANTI_TRANSPOSED:
             matrix[0 * 4 + 0] = 0;
-            matrix[0 * 4 + 1] = 1;
-            matrix[1 * 4 + 0] = 1;
             matrix[1 * 4 + 1] = 0;
+            matrix[2 * 4 + 2] = -1;
+            matrix[0 * 4 + 1] = -1;
+            matrix[1 * 4 + 0] = -1;
+            matrix[3 * 4 + 0] = 1;
+            matrix[3 * 4 + 1] = 1;
             break;
         default:
             break;
     }
-
-    if (rotate) {
-
-        matrix[0 * 4 + 0] = cos;
-        matrix[0 * 4 + 1] = -sin;
-        matrix[1 * 4 + 0] = sin;
-        matrix[1 * 4 + 1] = cos;
-    }
 }
 
 static int BuildSphere(unsigned nbPlanes,