#include <mbgl/shader/icon_shader.hpp>
#include <mbgl/shader/shaders.hpp>
#include <mbgl/platform/gl.hpp>

#include <cstdio>

using namespace mbgl;

IconShader::IconShader()
    : Shader(
         "icon",
         shaders[ICON_SHADER].vertex,
         shaders[ICON_SHADER].fragment
         ) {
    a_pos = MBGL_CHECK_ERROR(glGetAttribLocation(program, "a_pos"));
    a_offset = MBGL_CHECK_ERROR(glGetAttribLocation(program, "a_offset"));
    a_data1 = MBGL_CHECK_ERROR(glGetAttribLocation(program, "a_data1"));
    a_data2 = MBGL_CHECK_ERROR(glGetAttribLocation(program, "a_data2"));
}

void IconShader::bind(char *offset) {
    const int stride = 16;

    MBGL_CHECK_ERROR(glEnableVertexAttribArray(a_pos));
    MBGL_CHECK_ERROR(glVertexAttribPointer(a_pos, 2, GL_SHORT, false, stride, offset + 0));

    MBGL_CHECK_ERROR(glEnableVertexAttribArray(a_offset));
    MBGL_CHECK_ERROR(glVertexAttribPointer(a_offset, 2, GL_SHORT, false, stride, offset + 4));

    MBGL_CHECK_ERROR(glEnableVertexAttribArray(a_data1));
    MBGL_CHECK_ERROR(glVertexAttribPointer(a_data1, 4, GL_UNSIGNED_BYTE, false, stride, offset + 8));

    MBGL_CHECK_ERROR(glEnableVertexAttribArray(a_data2));
    MBGL_CHECK_ERROR(glVertexAttribPointer(a_data2, 4, GL_UNSIGNED_BYTE, false, stride, offset + 12));
}