Option 1 for fixing android 4.4

Reinit vertex attribute pointer each time, performance may hurt

data/shaders/colortexturedquad.vert

@@ -6,11 +6,11 @@ uniform vec2 texsize;
 #ifdef Explicit_Attrib_Location_Usable
 layout(location=0) in vec2 Position;
 layout(location=3) in vec2 Texcoord;
-layout(location=2) in uvec4 Color;
+layout(location=2) in vec4 Color;
 #else
 in vec2 Position;
 in vec2 Texcoord;
-in uvec4 Color;
+in vec4 Color;
 #endif
 
 out vec2 uv;
@@ -18,7 +18,7 @@ out vec4 col;
 
 void main()
 {
-    col = vec4(Color) / 255.;
+    col = Color.zyxw;
     uv = Texcoord * texsize + texcenter;
     gl_Position = vec4(Position * size + center, 0., 1.);
 }

src/graphics/2dutils.cpp

@@ -93,41 +93,12 @@ class ColoredTextureRectShader : public TextureShader<ColoredTextureRectShader,
                                                core::vector2df, core::vector2df,
                                                core::vector2df, core::vector2df>
 {
-#ifdef XX
-private:
-    GLuint m_quad_buffer;
-
-    void initQuadBuffer()
-    {
-        const float quad_vertex[] = { -1., -1., -1.,  1.,   // UpperLeft
-                                      -1.,  1., -1., -1.,   // LowerLeft
-                                       1., -1.,  1.,  1.,   // UpperRight
-                                       1.,  1.,  1., -1. }; // LowerRight 
-        glGenBuffers(1, &m_quad_buffer);
-        glBindBuffer(GL_ARRAY_BUFFER, m_quad_buffer);
-        glBufferData(GL_ARRAY_BUFFER, 16 * sizeof(float), quad_vertex,
-                     GL_STATIC_DRAW);
-
-        glGenVertexArrays(1, &SharedObject::UIVAO);
-        glBindVertexArray(SharedObject::UIVAO);
-        glEnableVertexAttribArray(0);
-        glEnableVertexAttribArray(3);
-        glBindBuffer(GL_ARRAY_BUFFER, m_quad_buffer);
-        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), 0);
-        glVertexAttribPointer(3, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), 
-                              (GLvoid *)(2 * sizeof(float)));
-        glBindVertexArray(0);
-    }   // initQuadBuffer
-#endif
 public:
     GLuint m_color_vbo;
     GLuint m_vao;
 
     ColoredTextureRectShader()
     {
-#ifdef XX
-        initQuadBuffer();
-#endif
         loadProgram(OBJECT, GL_VERTEX_SHADER, "colortexturedquad.vert",
                             GL_FRAGMENT_SHADER, "colortexturedquad.frag");
         assignUniforms("center", "size", "texcenter", "texsize");
@@ -143,16 +114,15 @@ public:
         glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), 0);
         glVertexAttribPointer(3, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), 
                               (GLvoid *)(2 * sizeof(float)));
-        const unsigned quad_color[] = {   0,   0,   0, 255,
+        glBindVertexArray(0);
+        const uint8_t quad_color[] = {   0,   0,   0, 255,
                                         255,   0,   0, 255,
                                           0, 255,   0, 255,
                                           0,   0, 255, 255 };
         glGenBuffers(1, &m_color_vbo);
         glBindBuffer(GL_ARRAY_BUFFER, m_color_vbo);
-        glBufferData(GL_ARRAY_BUFFER, 16 * sizeof(unsigned), quad_color,
+        glBufferData(GL_ARRAY_BUFFER, 16, quad_color, GL_DYNAMIC_DRAW);
-                     GL_DYNAMIC_DRAW);
+
-        glVertexAttribIPointer(2, 4, GL_UNSIGNED_INT, 4 * sizeof(unsigned), 0);
-        glBindVertexArray(0);
     }   // ColoredTextureRectShader
 };   // ColoredTextureRectShader
 
@@ -164,16 +134,11 @@ static void drawTexColoredQuad(const video::ITexture *texture,
                                float tex_center_pos_y, float tex_width,
                                float tex_height)
 {
-    unsigned colors[] = {
+    glBindVertexArray(ColoredTextureRectShader::getInstance()->m_vao);
-        col[0].getRed(), col[0].getGreen(), col[0].getBlue(), col[0].getAlpha(),
-        col[1].getRed(), col[1].getGreen(), col[1].getBlue(), col[1].getAlpha(),
-        col[2].getRed(), col[2].getGreen(), col[2].getBlue(), col[2].getAlpha(),
-        col[3].getRed(), col[3].getGreen(), col[3].getBlue(), col[3].getAlpha(),
-    };
-
     glBindBuffer(GL_ARRAY_BUFFER,
                  ColoredTextureRectShader::getInstance()->m_color_vbo);
-    glBufferSubData(GL_ARRAY_BUFFER, 0, 16 * sizeof(unsigned), colors);
+    glBufferSubData(GL_ARRAY_BUFFER, 0, 16, col);
+    glVertexAttribPointer(2, 4, GL_UNSIGNED_BYTE, GL_TRUE, 4 , 0);
 
     ColoredTextureRectShader::getInstance()->use();
     glBindVertexArray(ColoredTextureRectShader::getInstance()->m_vao);
@@ -186,8 +151,9 @@ static void drawTexColoredQuad(const video::ITexture *texture,
                       core::vector2df(tex_width, tex_height));
 
     glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
-    glBindVertexArray(0);
     glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindVertexArray(0);
+
 
     glGetError();
 }   // drawTexColoredQuad