Evas gl_x11: Fix usage of glReadPixels

It is not necessary to dynamically link to glReadPixels since
this is not an extension. This code wouldn't even work on some
devices.

Also, the pixels returned are not premultiplied (yeah >_<)

And some devices (EGL) don't support GL_BGRA... so glReadPixels
would just fail and not fill in the pixels. Conversion is required.

diff --git a/src/modules/evas/engines/gl_common/evas_gl_common.h b/src/modules/evas/engines/gl_common/evas_gl_common.h
index 3f5bab2..70db622 100644 (file)
--- a/src/modules/evas/engines/gl_common/evas_gl_common.h
+++ b/src/modules/evas/engines/gl_common/evas_gl_common.h
@@ -839,8 +839,6 @@ extern void       (*glsym_glReleaseShaderCompiler)(void);
 extern void      *(*glsym_glMapBuffer)            (GLenum a, GLenum b);
 extern GLboolean  (*glsym_glUnmapBuffer)          (GLenum a);
 
-extern void       (*glsym_glReadPixels)           (GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLvoid *data);
-
 #ifdef GL_GLES
 extern void          *(*secsym_eglCreateImage)               (void *a, void *b, GLenum c, void *d, const int *e);
 extern unsigned int   (*secsym_eglDestroyImage)              (void *a, void *b);

diff --git a/src/modules/evas/engines/gl_common/evas_gl_context.c b/src/modules/evas/engines/gl_common/evas_gl_context.c
index 000a396..2e447d9 100644 (file)
--- a/src/modules/evas/engines/gl_common/evas_gl_context.c
+++ b/src/modules/evas/engines/gl_common/evas_gl_context.c
@@ -29,7 +29,6 @@ void      *(*glsym_glMapBuffer)            (GLenum a, GLenum b) = NULL;
 GLboolean  (*glsym_glUnmapBuffer)          (GLenum a) = NULL;
 void       (*glsym_glStartTiling)          (GLuint a, GLuint b, GLuint c, GLuint d, GLuint e) = NULL;
 void       (*glsym_glEndTiling)            (GLuint a) = NULL;
-void       (*glsym_glReadPixels)           (GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLvoid *data) = NULL;
 
 #ifdef GL_GLES
 // just used for finding symbols :)
@@ -212,8 +211,6 @@ gl_symbols(void)
 
    FINDSYM(secsym_eglGetImageAttribSEC, "eglGetImageAttribSEC", secsym_func_uint);
 #endif
-
-   FINDSYM(glsym_glReadPixels, "glReadPixels", glsym_func_void);
 }
 
 static void shader_array_flush(Evas_Engine_GL_Context *gc);

diff --git a/src/modules/evas/engines/gl_x11/evas_engine.c b/src/modules/evas/engines/gl_x11/evas_engine.c
index 96d2726..82ffd05 100644 (file)
--- a/src/modules/evas/engines/gl_x11/evas_engine.c
+++ b/src/modules/evas/engines/gl_x11/evas_engine.c
@@ -3435,9 +3435,31 @@ eng_gl_surface_read_pixels(void *data, void *surface,
 # endif
 #endif
 
+   /* Since this is an FBO, the pixels are already in the right Y order.
+    * But some devices don't support GL_BGRA, so we still need to convert.
+    */
+
    glsym_glBindFramebuffer(GL_FRAMEBUFFER, im->tex->pt->fb);
-   glsym_glReadPixels(x, y, w, h, GL_BGRA, GL_UNSIGNED_BYTE, pixels);
+   if (im->tex->pt->format == GL_BGRA)
+     glReadPixels(x, y, w, h, GL_BGRA, GL_UNSIGNED_BYTE, pixels);
+   else
+     {
+        DATA32 *ptr = pixels;
+        int k;
+
+        glReadPixels(x, y, w, h, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
+        for (k = w * h; k; --k)
+          {
+             const DATA32 v = *ptr;
+             *ptr++ = (v & 0xFF00FF00)
+                   | ((v & 0x00FF0000) >> 16)
+                   | ((v & 0x000000FF) << 16);
+          }
+     }
    glsym_glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+   evas_common_convert_argb_premul(pixels, w * h);
+
    return EINA_TRUE;
 }
 //--------------------------------//