opengl: move fragment shader creation to renderer

The helper fragment_shaders.c was responsible to create the whole
fragment shaders. For now on, make it responsible to generate only the
piece of GLSL code necessary to access the input picture (i.e. to
implement vlc_texture()).

Make the renderer create its own fragment shader, using the
vlc_texture() function generated by fragment_shaders.c.

modules/video_output/opengl/fragment_shaders.c

@@ -336,8 +336,6 @@ xyz12_shader_init(struct vlc_gl_renderer *renderer)
      *  - reverse RGB gamma correction
      */
     static const char *template =
-        "#version %u\n"
-        "%s"
         "uniform sampler2D Texture0;"
         "uniform vec4 xyz_gamma = vec4(2.6);"
         "uniform vec4 rgb_gamma = vec4(1.0/2.2);"
@@ -349,7 +347,6 @@ xyz12_shader_init(struct vlc_gl_renderer *renderer)
         "    0.0,      0.0,         0.0,        1.0 "
         " );"
 
-        "varying vec2 PicCoords;"
         "vec4 vlc_texture(vec2 pic_coords)\n"
         "{ "
         " vec4 v_in, v_out;"
@@ -359,17 +356,9 @@ xyz12_shader_init(struct vlc_gl_renderer *renderer)
         " v_out = pow(v_out, rgb_gamma) ;"
         " v_out = clamp(v_out, 0.0, 1.0) ;"
         " return v_out;"
-        "}\n"
-        "void main() {\n"
-        " gl_FragColor = vlc_texture(PicCoords);\n"
         "}\n";
 
-    char *code;
-    if (asprintf(&code, template, renderer->glsl_version,
-                 renderer->glsl_precision_header) < 0)
-        return NULL;
-
-    return code;
+    return strdup(template);
 }
 
 static int
@@ -484,15 +473,7 @@ opengl_fragment_shader_init(struct vlc_gl_renderer *renderer, GLenum tex_target,
 #define ADD(x) vlc_memstream_puts(&ms, x)
 #define ADDF(x, ...) vlc_memstream_printf(&ms, x, ##__VA_ARGS__)
 
-    ADDF("#version %u\n", renderer->glsl_version);
-
-    if (tex_target == GL_TEXTURE_EXTERNAL_OES)
-        ADDF("#extension GL_OES_EGL_image_external : require\n");
-
-    ADDF("%s", renderer->glsl_precision_header);
-
-    ADD("varying vec2 PicCoords;\n"
-        "uniform mat4 TransformMatrix;\n"
+    ADD("uniform mat4 TransformMatrix;\n"
         "uniform mat4 OrientationMatrix;\n");
     for (unsigned i = 0; i < interop->tex_count; ++i)
         ADDF("uniform %s Texture%u;\n"
@@ -642,20 +623,12 @@ opengl_fragment_shader_init(struct vlc_gl_renderer *renderer, GLenum tex_target,
     ADD(" return result * FillColor;\n"
         "}\n");
 
-    ADD("void main() {\n"
-        " gl_FragColor = vlc_texture(PicCoords);\n"
-        "}\n");
-
 #undef ADD
 #undef ADDF
 
     if (vlc_memstream_close(&ms) != 0)
         return NULL;
 
-    if (renderer->b_dump_shaders)
-        msg_Dbg(renderer->gl, "\n=== Fragment shader for fourcc: %4.4s, colorspace: %d ===\n%s\n",
-                (const char *)&chroma, yuv_space, ms.ptr);
-
     renderer->pf_fetch_locations = renderer_base_fetch_locations;
     renderer->pf_prepare_shader = renderer_base_prepare_shader;
 

modules/video_output/opengl/renderer.c

@@ -273,6 +273,47 @@ BuildVertexShader(const struct vlc_gl_renderer *renderer)
     return code;
 }
 
+static char *
+BuildFragmentShader(struct vlc_gl_renderer *renderer)
+{
+    struct vlc_gl_interop *interop = renderer->interop;
+    char *vlc_texture =
+        opengl_fragment_shader_init(renderer, interop->tex_target,
+                                    interop->sw_fmt.i_chroma,
+                                    interop->sw_fmt.space);
+    if (!vlc_texture)
+        return NULL;
+
+    static const char *template =
+        "#version %u\n"
+        "%s" /* extensions */
+        "%s" /* precision header */
+        "%s" /* vlc_texture definition */
+        "varying vec2 PicCoords;\n"
+        "void main() {\n"
+        " gl_FragColor = vlc_texture(PicCoords);\n"
+        "}\n";
+
+    /* TODO move extensions back to fragment_shaders.c */
+    const char *extensions = interop->tex_target == GL_TEXTURE_EXTERNAL_OES
+                           ? "#extension GL_OES_EGL_image_external : require\n"
+                           : "";
+
+    char *code;
+    int ret = asprintf(&code, template, renderer->glsl_version, extensions,
+                       renderer->glsl_precision_header, vlc_texture);
+    free(vlc_texture);
+    if (ret < 0)
+        return NULL;
+
+    if (renderer->b_dump_shaders)
+        msg_Dbg(renderer->gl, "\n=== Fragment shader for fourcc: %4.4s, colorspace: %d ===\n%s\n",
+                              (const char *) &interop->sw_fmt.i_chroma,
+                              interop->sw_fmt.space, code);
+
+    return code;
+}
+
 static int
 opengl_link_program(struct vlc_gl_renderer *renderer)
 {
@@ -283,10 +324,7 @@ opengl_link_program(struct vlc_gl_renderer *renderer)
     if (!vertex_shader)
         return VLC_EGENERIC;
 
-    char *fragment_shader =
-        opengl_fragment_shader_init(renderer, interop->tex_target,
-                                    interop->sw_fmt.i_chroma,
-                                    interop->sw_fmt.space);
+    char *fragment_shader = BuildFragmentShader(renderer);
     if (!fragment_shader)
     {
         free(vertex_shader);