Updated version of `draw_sprite_pos_fixed` to work with modern GameMaker

draw_sprite_pos_fixed.gml

function draw_pos_fixed(surface, top_left_x, top_left_y, top_right_x, top_right_y, bottom_right_x, bottom_right_y, bottom_left_x, bottom_left_y, colour, alpha) {

    var cx, cy, s, t, q, v_buffer;

    var texture = surface_get_texture(surface);
    var uvs = texture_get_uvs(texture);

    var ax = top_right_x - bottom_left_x;
    var ay = top_right_y - bottom_left_y;
    var bx = top_left_x - bottom_right_x;
    var by = top_left_y - bottom_right_y;

    var can = ax * by - ay * bx;

    var cx, cy, s, t, q, v_buffer;
    if (can != 0) {
        cx = bottom_left_x - bottom_right_x;
        cy = bottom_left_y - bottom_right_y;
        s = (ax * cy - ay * cx) / can;
        if (s > 0 and s < 1) {
            t = (bx * cy - by * cx) / can;
            if (t > 0 and t < 1) {
                q[0] = 1 / (1 - t);
                q[1] = 1 / (1 - s);
                q[2] = 1 / t;
                q[3] = 1 / s;
                v_buffer = vertex_create_buffer();

                vertex_begin(v_buffer, global.format_perspective);

                // Top left
                vertex_position(v_buffer, top_left_x, top_left_y);
                vertex_normal(v_buffer, q[3] * uvs[0], q[3] * uvs[1], q[3]);
                vertex_colour(v_buffer, colour, alpha);
                vertex_texcoord(v_buffer, 0, 0);

                // Top right
                vertex_position(v_buffer, top_right_x, top_right_y);
                vertex_normal(v_buffer, q[2] * uvs[2], q[2] * uvs[1], q[2]);
                vertex_colour(v_buffer, colour, alpha);
                vertex_texcoord(v_buffer, 0, 1);

                // Bottom left
                vertex_position(v_buffer, bottom_left_x, bottom_left_y);
                vertex_normal(v_buffer, q[0] * uvs[0], q[0] * uvs[3], q[0]);
                vertex_colour(v_buffer, colour, alpha);
                vertex_texcoord(v_buffer, 1, 0);

                // Bottom right
                vertex_position(v_buffer, bottom_right_x, bottom_right_y);
                vertex_normal(v_buffer, q[1] * uvs[2], q[1] * uvs[3], q[1]);
                vertex_colour(v_buffer, colour, alpha);
                vertex_texcoord(v_buffer, 1, 1);

                vertex_end(v_buffer);

                shader_set(sh_perspective);
                vertex_submit(v_buffer, pr_trianglestrip, texture);
                shader_reset();
                vertex_delete_buffer(v_buffer);
            }
        }
    }
}

sh_perspective.fsh

varying vec4 v_vColour;
varying vec3 v_vNormal;

void main()
{
    gl_FragColor = v_vColour * texture2D(gm_BaseTexture, v_vNormal.xy / v_vNormal.z);
}

sh_perspective.vsh

attribute vec3 in_Position;                  // (x,y,z)
attribute vec3 in_Normal;                    // (qu,qv,q)
attribute vec4 in_Colour;                    // (r,g,b,a)
//attribute vec2 in_TextureCoord;            // (u,v) -- unused in this shader.

varying vec4 v_vColour;
varying vec3 v_vNormal;

void main()
{
    vec4 object_space_pos = vec4(in_Position.x, in_Position.y, in_Position.z, 1.0);
    gl_Position = gm_Matrices[MATRIX_WORLD_VIEW_PROJECTION] * object_space_pos;    
    v_vColour = in_Colour;
    v_vNormal = in_Normal;
}