Add some asserts.

[movit] / init.cpp

diff --git a/init.cpp b/init.cpp
index f6f45a04dde17331b385ec4aca77df8dd6e77fa7..c37614e4c58de3e3be37ea93f804e2aeace978ea 100644 (file)
--- a/init.cpp
+++ b/init.cpp
@@ -18,6 +18,7 @@ float movit_texel_subpixel_precision;
 bool movit_srgb_textures_supported;
 int movit_num_wrongly_rounded;
 bool movit_shader_rounding_supported;
+MovitShaderModel movit_shader_model;
 
 // The rules for objects with nontrivial constructors in static scope
 // are somewhat convoluted, and easy to mess up. We simply have a
@@ -78,7 +79,8 @@ void measure_texel_subpixel_precision()
        glViewport(0, 0, width, 1);
 
        GLuint glsl_program_num = resource_pool.compile_glsl_program(
-               read_file("vs.vert"), read_file("texture1d.frag"));
+               read_version_dependent_file("vs", "vert"),
+               read_version_dependent_file("texture1d", "frag"));
        glUseProgram(glsl_program_num);
        check_error();
        glUniform1i(glGetUniformLocation(glsl_program_num, "tex"), 0);  // Bind the 2D sampler.
@@ -209,7 +211,8 @@ void measure_roundoff_problems()
        glViewport(0, 0, 512, 1);
 
        GLuint glsl_program_num = resource_pool.compile_glsl_program(
-               read_file("vs.vert"), read_file("texture1d.frag"));
+               read_version_dependent_file("vs", "vert"),
+               read_version_dependent_file("texture1d", "frag"));
        glUseProgram(glsl_program_num);
        check_error();
        glUniform1i(glGetUniformLocation(glsl_program_num, "tex"), 0);  // Bind the 2D sampler.
@@ -280,13 +283,10 @@ bool check_extensions()
        // GLES generally doesn't use extensions as actively as desktop OpenGL.
        // For now, we say that for GLES, we require GLES 3, which has everything
        // we need.
-       //
-       // Since we use implicit #version 100, we don't have round(). We will
-       // fix this at some later stage.
        if (!epoxy_is_desktop_gl()) {
                if (epoxy_gl_version() >= 30) {
                        movit_srgb_textures_supported = true;
-                       movit_shader_rounding_supported = false;
+                       movit_shader_rounding_supported = true;
                } else {
                        return false;
                }
@@ -334,6 +334,42 @@ bool check_extensions()
        return true;
 }
 
+double get_glsl_version()
+{
+       char *glsl_version_str = strdup((const char *)glGetString(GL_SHADING_LANGUAGE_VERSION));
+
+       // Skip past the first period.
+       char *ptr = strchr(glsl_version_str, '.');
+       assert(ptr != NULL);
+       ++ptr;
+
+       // Now cut the string off at the next period or space, whatever comes first
+       // (unless the string ends first).
+       while (*ptr && *ptr != '.' && *ptr != ' ') {
+               ++ptr;
+       }
+       *ptr = '\0';
+
+       // Now we have something on the form X.YY. We convert it to a float, and hope
+       // that if it's inexact (e.g. 1.30), atof() will round the same way the
+       // compiler will.
+       float glsl_version = atof(glsl_version_str);
+       free(glsl_version_str);
+
+       return glsl_version;
+}
+
+void APIENTRY debug_callback(GLenum source,
+                             GLenum type,
+                             GLuint id,
+                             GLenum severity,
+                             GLsizei length,
+                             const char *message,
+                             const void *userParam)
+{
+       printf("Debug: %s\n", message);
+}
+
 }  // namespace
 
 bool init_movit(const string& data_directory, MovitDebugLevel debug_level)
@@ -350,9 +386,27 @@ bool init_movit(const string& data_directory, MovitDebugLevel debug_level)
        glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
        glDisable(GL_DITHER);
 
+       // You can turn this on if you want detailed debug messages from the driver.
+       // You should probably also ask for a debug context (see gtest_sdl_main.cpp),
+       // or you might not get much data back.
+       // glDebugMessageCallbackARB(callback, NULL);
+       // glDebugMessageControlARB(GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, 0, GL_TRUE);
+
        if (!check_extensions()) {
                return false;
        }
+
+       // Find out what shader model we should compile for.
+       if (epoxy_is_desktop_gl()) {
+               if (get_glsl_version() >= 1.30) {
+                       movit_shader_model = MOVIT_GLSL_130;
+               } else {
+                       movit_shader_model = MOVIT_GLSL_110;
+               }
+       } else {
+               movit_shader_model = MOVIT_ESSL_300;
+       }
+
        measure_texel_subpixel_precision();
        measure_roundoff_problems();