Check required extensions at start.

[movit] / init.cpp

diff --git a/init.cpp b/init.cpp
index 129ee4c894d91ea3d5072b35a9812338981707fc..ac52aa2ce3d7eee956e6cc629912e699bb6553b1 100644 (file)
--- a/init.cpp
+++ b/init.cpp
@@ -2,8 +2,12 @@
 #include "opengl.h"
 #include "util.h"
 
 #include "opengl.h"
 #include "util.h"
 

+#include <set>
+#include <string>
+

 bool movit_initialized = false;
 float movit_texel_subpixel_precision;
 bool movit_initialized = false;
 float movit_texel_subpixel_precision;

+bool movit_srgb_textures_supported;

 
 namespace {
 
 
 namespace {
 


@@ -119,6 +123,43 @@ void measure_texel_subpixel_precision()
        check_error();
 }
 
        check_error();
 }
 

+void get_extensions(std::set<std::string> *extensions)
+{
+       char *str = strdup(reinterpret_cast<const char *>(glGetString(GL_EXTENSIONS)));
+       for (char *ptr = strtok(str, " "); ptr != NULL; ptr = strtok(NULL, " ")) {
+               extensions->insert(ptr);
+       }
+       free(str);
+}
+
+void check_extensions()
+{
+       std::set<std::string> extensions;
+       get_extensions(&extensions);
+
+       // We fundamentally need FBOs and floating-point textures.
+       assert(extensions.count("GL_ARB_framebuffer_object") != 0);
+       assert(extensions.count("GL_ARB_texture_float") != 0);
+
+       // We assume that we can use non-power-of-two textures without restrictions.
+       assert(extensions.count("GL_ARB_texture_non_power_of_two") != 0);
+
+       // We also need GLSL fragment shaders.
+       assert(extensions.count("GL_ARB_fragment_shader") != 0);
+       assert(extensions.count("GL_ARB_shading_language_100") != 0);
+
+       // FlatInput and YCbCrInput uses PBOs. (They could in theory do without,
+       // but no modern card would really not provide it.)
+       assert(extensions.count("GL_ARB_pixel_buffer_object") != 0);
+
+       // ResampleEffect uses RG textures to encode a two-component LUT.
+       assert(extensions.count("GL_ARB_texture_rg") != 0);
+
+       // sRGB texture decode would be nice, but are not mandatory
+       // (GammaExpansionEffect can do the same thing if needed).
+       movit_srgb_textures_supported = extensions.count("GL_EXT_texture_sRGB");
+}
+

 }  // namespace
 
 void init_movit()
 }  // namespace
 
 void init_movit()


@@ -132,6 +173,7 @@ void init_movit()
        glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 
        measure_texel_subpixel_precision();
        glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 
        measure_texel_subpixel_precision();

+       check_extensions();

 
        movit_initialized = true;
 }
 
        movit_initialized = true;
 }