evas: set visible texcolorpick texture in 3D shaders

Summary:
Add uniform varialble uColorTexture. Generate sampler count for textcolorpick
and pass to renderer for bind additional texture unit to gl.
It can be used for different 3D effects - blur, wave distortion, heat haze, etc.
T2761

Reviewers: Hermet, raster, cedric

Reviewed By: cedric

Differential Revision: https://phab.enlightenment.org/D3372

Signed-off-by: Cedric BAIL <cedric@osg.samsung.com>

src/modules/evas/engines/gl_common/evas_gl_3d.c

@@ -1122,13 +1122,19 @@ _mesh_draw_data_build(E3D_Draw_Data *data,
         _light_build(data, light, matrix_eye);
         eina_normal3_matrix_get(&data->matrix_normal, matrix_mv);
      }
-
-   int num;
+   /*Check possible quantity of texture units*/
+   int num, count = 0;
    glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &num);
    data->smap_sampler = num - 1;
 
-   if (data->texture_count >= num)
-     if ((data->flags & E3D_SHADER_FLAG_SHADOWED) || (data->texture_count > num))
+   if (data->render_to_texture)
+     {
+        count++;
+        data->colortex_sampler = num - (count + 1);
+     }
+   if (data->texture_count + count >= num)
+     if ((data->flags & E3D_SHADER_FLAG_SHADOWED) ||
+         (data->texture_count + count > num))
        {
           ERR("Too many textures for your graphics configuration.");
           return EINA_FALSE;
@@ -1144,6 +1150,7 @@ _mesh_draw(E3D_Renderer *renderer, Evas_Canvas3D_Mesh *mesh, int frame, Evas_Can
    E3D_Draw_Data   data;
 
    memset(&data, 0x00, sizeof(E3D_Draw_Data));
+   data.render_to_texture = e3d_renderer_rendering_to_texture_get(renderer);
 
    if (_mesh_draw_data_build(&data, mesh, frame, matrix_eye, matrix_mv, matrix_mvp, matrix_light, light))
      e3d_renderer_draw(renderer, &data);

src/modules/evas/engines/gl_common/evas_gl_3d_private.h

@@ -87,6 +87,7 @@ struct _E3D_Draw_Data
    Evas_Real shininess;
 
    GLint                   smap_sampler;
+   GLint                   colortex_sampler;
    Evas_Canvas3D_Blend_Func      blend_sfactor;
    Evas_Canvas3D_Blend_Func      blend_dfactor;
    Eina_Bool               blending : 1;
@@ -111,6 +112,8 @@ struct _E3D_Draw_Data
    Evas_Real               pcf_step;
    Evas_Real               pcf_size;
    Evas_Real               constant_bias;
+
+   Eina_Bool               render_to_texture;
 };
 
 struct _E3D_Texture
@@ -171,5 +174,5 @@ void                 e3d_renderer_clear(E3D_Renderer *renderer, const Evas_Color
 void                 e3d_renderer_draw(E3D_Renderer *renderer, E3D_Draw_Data *data);
 void                 e3d_renderer_flush(E3D_Renderer *renderer);
 void                 e3d_renderer_color_pick_target_set(E3D_Renderer *renderer, E3D_Drawable *drawable);
-
+Eina_Bool            e3d_renderer_rendering_to_texture_get(E3D_Renderer *renderer);
 #endif /* EVAS_GL_3D_PRIVATE_H */

src/modules/evas/engines/gl_common/evas_gl_3d_renderer.c

@@ -15,7 +15,10 @@ struct _E3D_Renderer
    Eina_Bool      vertex_attrib_enable[E3D_MAX_VERTEX_ATTRIB_COUNT];
    Eina_Bool      depth_test_enable;
    GLuint         texDepth;
-   GLint         smap_sampler;
+   GLint          smap_sampler;
+   Eina_Bool      render_to_texture;
+   GLuint         texcolorpick;
+   GLint          colortex_sampler;
 };
 
 static inline GLenum
@@ -208,6 +211,12 @@ _renderer_texture_bind(E3D_Renderer *renderer, E3D_Draw_Data *data)
         glBindTexture(GL_TEXTURE_2D, renderer->texDepth);
         renderer->smap_sampler = data->smap_sampler;
      }
+   if (renderer->render_to_texture)
+     {
+        glActiveTexture(GL_TEXTURE0 + data->colortex_sampler);
+        glBindTexture(GL_TEXTURE_2D, renderer->texcolorpick);
+        renderer->colortex_sampler = data->colortex_sampler;
+     }
 }
 
 static inline void
@@ -269,6 +278,8 @@ e3d_renderer_target_set(E3D_Renderer *renderer, E3D_Drawable *target)
    glViewport(0, 0, target->w, target->h);
    renderer->fbo = target->fbo;
    renderer->texDepth = target->texDepth;
+   renderer->texcolorpick = target->texcolorpick;
+   renderer->render_to_texture = EINA_FALSE;
 }
 
 void
@@ -288,6 +299,14 @@ e3d_renderer_color_pick_target_set(E3D_Renderer *renderer, E3D_Drawable *drawabl
 #endif
    glViewport(0, 0, drawable->w, drawable->h);
    renderer->texDepth = drawable->texDepth;
+   renderer->texcolorpick = drawable->texcolorpick;
+   renderer->render_to_texture = EINA_TRUE;
+}
+
+Eina_Bool
+e3d_renderer_rendering_to_texture_get(E3D_Renderer *renderer)
+{
+   return renderer->render_to_texture;
 }
 
 void

src/modules/evas/engines/gl_common/evas_gl_3d_shader.c

@@ -68,6 +68,7 @@ typedef enum _E3D_Uniform
    E3D_UNIFORM_COLOR_PICK,
    E3D_UNIFORM_ALPHATEST_COMPARISON,
    E3D_UNIFORM_ALPHATEST_REFVALUE,
+   E3D_UNIFORM_RENDER_TO_TEXTURE,
 
    E3D_UNIFORM_COUNT,
 } E3D_Uniform;
@@ -361,6 +362,7 @@ static const char *uniform_names[] =
    "uColorPick",
    "uAlphaTestComparison",
    "uAlphaTestRefValue",
+   "uColorTexture",
 };
 
 static inline void
@@ -630,6 +632,9 @@ _uniform_upload(E3D_Uniform u, GLint loc, const E3D_Draw_Data *data)
       case E3D_UNIFORM_ALPHATEST_REFVALUE:
          glUniform1f(loc, (data->alpha_ref_value ? data->alpha_ref_value : 0.0));
          break;
+      case E3D_UNIFORM_RENDER_TO_TEXTURE:
+         glUniform1i(loc, data->colortex_sampler);
+         break;
       default:
          ERR("Invalid uniform ID.");
          break;