RaspiStill: Add option to render preview via GL.

Add RaspiTex.c which demonstrates how the camera preview buffers can be
bound to EGL Images and rendered via Open GLES.

To enable GL rendering add --gl to the command line and select a
GL scene
* square - A simple rotating square
* teapot - The classic teapot demo
* mirror - OpenGL ES 2.X Hall of mirrors example

host_applications/linux/apps/raspicam/RaspiStill.c

@@ -74,6 +74,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "RaspiCamControl.h"
 #include "RaspiPreview.h"
 #include "RaspiCLI.h"
+#include "RaspiTex.h"
 
 #include <semaphore.h>
 
@@ -132,6 +133,7 @@ typedef struct
    int timelapse;                      /// Delay between each picture in timelapse mode. If 0, disable timelapse
    int fullResPreview;                 /// If set, the camera preview port runs at capture resolution. Reduces fps.
    int frameNextMethod;                /// Which method to use to advance to next frame
+   int useGL;                          /// Render preview using OpenGL
 
    RASPIPREVIEW_PARAMETERS preview_parameters;    /// Preview setup parameters
    RASPICAM_CAMERA_PARAMETERS camera_parameters; /// Camera setup parameters
@@ -144,6 +146,8 @@ typedef struct
 
    MMAL_POOL_T *encoder_pool; /// Pointer to the pool of buffers used by encoder output port
 
+   RASPITEX_STATE raspitex_state; /// GL renderer state and parameters
+
 } RASPISTILL_STATE;
 
 /** Struct used to pass information in encoder port userdata to callback
@@ -176,6 +180,7 @@ static void store_exif_tag(RASPISTILL_STATE *state, const char *exif_tag);
 #define CommandLink         14
 #define CommandKeypress     15
 #define CommandSignal       16
+#define CommandGL           17
 
 static COMMAND_LIST cmdline_commands[] =
 {
@@ -196,6 +201,7 @@ static COMMAND_LIST cmdline_commands[] =
    { CommandFullResPreview,"-fullpreview","fp", "Run the preview using the still capture resolution (may reduce preview fps)", 0},
    { CommandKeypress,"-keypress",   "k",  "Wait between captures for a ENTER, X then ENTER to exit", 0},
    { CommandSignal,  "-signal",     "s",  "Wait between captures for a SIGUSR1 from another process", 0},
+   { CommandGL,      "-gl",         "g",  "Draw preview to texture instead of using video render component", 0},
 };
 
 static int cmdline_commands_size = sizeof(cmdline_commands) / sizeof(cmdline_commands[0]);
@@ -269,12 +275,16 @@ static void default_status(RASPISTILL_STATE *state)
    state->timelapse = 0;
    state->fullResPreview = 0;
    state->frameNextMethod = FRAME_NEXT_SINGLE;
+   state->useGL = 0;
 
    // Setup preview window defaults
    raspipreview_set_defaults(&state->preview_parameters);
 
    // Set up the camera_parameters to default
    raspicamcontrol_set_defaults(&state->camera_parameters);
+
+   // Set initial GL preview state
+   raspitex_set_defaults(&state->raspitex_state);
 }
 
 /**
@@ -570,6 +580,10 @@ static int parse_cmdline(int argc, const char **argv, RASPISTILL_STATE *state)
          signal(SIGUSR1, signal_handler);
          break;
 
+      case CommandGL:
+         state->useGL = 1;
+         break;
+
       default:
       {
          // Try parsing for any image specific parameters
@@ -582,6 +596,10 @@ static int parse_cmdline(int argc, const char **argv, RASPISTILL_STATE *state)
          if (!parms_used)
             parms_used = raspipreview_parse_cmdline(&state->preview_parameters, &argv[i][1], second_arg);
 
+         // Still unused, try GL preview options
+         if (!parms_used)
+            parms_used = raspitex_parse_cmdline(&state->raspitex_state, &argv[i][1], second_arg);
+
          // If no parms were used, this must be a bad parameters
          if (!parms_used)
             valid = 0;
@@ -593,6 +611,17 @@ static int parse_cmdline(int argc, const char **argv, RASPISTILL_STATE *state)
       }
    }
 
+   /* GL preview parameters use preview parameters as defaults unless overriden */
+   if (! state->raspitex_state.gl_win_defined)
+   {
+      state->raspitex_state.x       = state->preview_parameters.previewWindow.x;
+      state->raspitex_state.y       = state->preview_parameters.previewWindow.y;
+      state->raspitex_state.width   = state->preview_parameters.previewWindow.width;
+      state->raspitex_state.height  = state->preview_parameters.previewWindow.height;
+   }
+   state->raspitex_state.opacity = state->preview_parameters.opacity;
+   state->raspitex_state.verbose = state->verbose;
+
    if (!valid)
    {
       fprintf(stderr, "Invalid command line option (%s)\n", argv[i]);
@@ -622,6 +651,9 @@ static void display_valid_parameters(char *app_name)
    // Now display any help information from the camcontrol code
    raspicamcontrol_display_help();
 
+   // Now display GL preview help
+   raspitex_display_help();
+
    fprintf(stderr, "\n");
 
    return;
@@ -714,10 +746,8 @@ static void encoder_buffer_callback(MMAL_PORT_T *port, MMAL_BUFFER_HEADER_T *buf
 
    if (complete)
       vcos_semaphore_post(&(pData->complete_semaphore));
-
 }
 
-
 /**
  * Create the camera component, set up its ports
  *
@@ -793,7 +823,6 @@ static MMAL_STATUS_T create_camera_component(RASPISTILL_STATE *state)
    // Now set up the port formats
 
    format = preview_port->format;
-
    format->encoding = MMAL_ENCODING_OPAQUE;
    format->encoding_variant = MMAL_ENCODING_I420;
 
@@ -824,7 +853,6 @@ static MMAL_STATUS_T create_camera_component(RASPISTILL_STATE *state)
    }
 
    status = mmal_port_format_commit(preview_port);
-
    if (status != MMAL_SUCCESS)
    {
       vcos_log_error("camera viewfinder format couldn't be set");
@@ -880,6 +908,16 @@ static MMAL_STATUS_T create_camera_component(RASPISTILL_STATE *state)
       goto error;
    }
 
+   if (state->useGL)
+   {
+      status = raspitex_configure_preview_port(&state->raspitex_state, preview_port);
+      if (status != MMAL_SUCCESS)
+      {
+         fprintf(stderr, "Failed to configure preview port for GL rendering");
+         goto error;
+      }
+   }
+
    state->camera_component = camera;
 
    if (state->verbose)
@@ -910,8 +948,6 @@ static void destroy_camera_component(RASPISTILL_STATE *state)
    }
 }
 
-
-
 /**
  * Create the encoder component, set up its ports
  *
@@ -1466,6 +1502,9 @@ int main(int argc, const char **argv)
       dump_status(&state);
    }
 
+   if (state.useGL)
+      raspitex_init(&state.raspitex_state);
+
    // OK, we have a nice set of parameters. Now set up our components
    // We have three components. Camera, Preview and encoder.
    // Camera and encoder are different in stills/video, but preview
@@ -1476,7 +1515,7 @@ int main(int argc, const char **argv)
       vcos_log_error("%s: Failed to create camera component", __func__);
       exit_code = EX_SOFTWARE;
    }
-   else if ((status = raspipreview_create(&state.preview_parameters)) != MMAL_SUCCESS)
+   else if ((!state.useGL) && (status = raspipreview_create(&state.preview_parameters)) != MMAL_SUCCESS)
    {
       vcos_log_error("%s: Failed to create preview component", __func__);
       destroy_camera_component(&state);
@@ -1502,12 +1541,18 @@ int main(int argc, const char **argv)
       encoder_input_port  = state.encoder_component->input[0];
       encoder_output_port = state.encoder_component->output[0];
 
-      // Note we are lucky that the preview and null sink components use the same input port
-      // so we can simple do this without conditionals
-      preview_input_port  = state.preview_parameters.preview_component->input[0];
+      if (! state.useGL)
+      {
+         if (state.verbose)
+            fprintf(stderr, "Connecting camera preview port to video render.\n");
 
-      // Connect camera to preview (which might be a null_sink if no preview required)
-      status = connect_ports(camera_preview_port, preview_input_port, &state.preview_connection);
+         // Note we are lucky that the preview and null sink components use the same input port
+         // so we can simple do this without conditionals
+         preview_input_port  = state.preview_parameters.preview_component->input[0];
+
+         // Connect camera to preview (which might be a null_sink if no preview required)
+         status = connect_ports(camera_preview_port, preview_input_port, &state.preview_connection);
+      }
 
       if (status == MMAL_SUCCESS)
       {
@@ -1533,6 +1578,10 @@ int main(int argc, const char **argv)
 
          vcos_assert(vcos_status == VCOS_SUCCESS);
 
+         /* If GL preview is requested then start the GL threads */
+         if (state.useGL && (raspitex_start(&state.raspitex_state) != 0))
+            goto error;
+
          if (status != MMAL_SUCCESS)
          {
             vcos_log_error("Failed to setup encoder output");
@@ -1734,13 +1783,22 @@ error:
       if (state.verbose)
          fprintf(stderr, "Closing down\n");
 
+      if (state.useGL)
+      {
+         raspitex_stop(&state.raspitex_state);
+         raspitex_destroy(&state.raspitex_state);
+      }
+
       // Disable all our ports that are not handled by connections
       check_disable_port(camera_video_port);
       check_disable_port(encoder_output_port);
 
-      mmal_connection_destroy(state.preview_connection);
+      if (state.preview_connection)
+         mmal_connection_destroy(state.preview_connection);
+
+      if (state.encoder_connection)
+         mmal_connection_destroy(state.encoder_connection);
 
-      mmal_connection_destroy(state.encoder_connection);
 
       /* Disable components */
       if (state.encoder_component)