#include <cairo/cairo.h>
#include <cairo/cairo-pdf.h>

#include <math.h>

// Build with:
// gcc -g `pkg-config --cflags --libs cairo` copy.c
int main(int argc, char *argv[])
{

        // Make a PDF surface
        const char fileName[] = "unused.pdf";
        const double pntWidth = 1000;
        const double pntHeight = 1000;
        cairo_surface_t *pdfSurface = cairo_pdf_surface_create(
                        fileName, pntWidth, pntHeight);
        cairo_t *pdfContext = cairo_create(pdfSurface);

        const double xMinUser = 0.0;
        const double yMinUser = 0.0;
        const double xMaxUser = 10000.0;
        const double yMaxUser = 10000.0;

        // Set up the transform (rotation, etc)
        {
                const double userWidth = xMaxUser - xMinUser;
                const double userHeight = yMaxUser - yMinUser;
                const double scaleX = pntWidth / userWidth;
                const double scaleY = pntHeight / userHeight;

                // Rotate about the centre of the VP
                const int vpCenX = pntWidth / 2;
                const int vpCenY = pntHeight / 2;
                const double txRotRad = 0 * M_PI / 180.0;
                cairo_translate(pdfContext, vpCenX, vpCenY);
                cairo_rotate(pdfContext, txRotRad);
                cairo_translate(pdfContext, -vpCenX, -vpCenY);

                cairo_translate(pdfContext, 0, pntHeight);
                cairo_scale(pdfContext, scaleX, -scaleY);
                cairo_translate(pdfContext, -xMinUser, -yMinUser);

        }

        // Draw a bunch of stuff
        {
                // Line
                cairo_move_to(pdfContext, xMaxUser-100, yMaxUser-100);
                cairo_line_to(pdfContext, xMinUser+100, yMinUser+100);
                cairo_set_source_rgba(pdfContext, 1.0, 0.0, 0.0, 1);
                cairo_stroke(pdfContext);

                // Polygon
                cairo_move_to(pdfContext, (xMinUser + xMaxUser)/2.0,
                              (yMinUser + yMaxUser)/2.0);
                cairo_rel_line_to(pdfContext, 0, 250);
                cairo_rel_line_to(pdfContext, -250, -250);
                cairo_close_path(pdfContext);
                cairo_set_source_rgba(pdfContext, 0.0, 0.0, 1.0, 1);
                cairo_fill(pdfContext);
        }


        // Make the image surface
        const int pixWidth = 1000;
        const int pixHeight = 1000;
        cairo_surface_t *imgSurface = cairo_image_surface_create(
                CAIRO_FORMAT_RGB24, pixWidth, pixHeight);
        cairo_t *imgContext = cairo_create(imgSurface);
        cairo_set_antialias(imgContext, CAIRO_ANTIALIAS_NONE);

        // Copy the PDF to the image
        {
                cairo_translate(imgContext, -11200, -11200);
                cairo_scale(imgContext, 24, 24);
                cairo_set_source_surface(imgContext, pdfSurface, 0, 0);
                cairo_paint(imgContext);

/*                 // The whole surface */
/*                 cairo_set_source_surface(imgContext, pdfSurface, 0, 0); */
/*                 cairo_paint(imgContext); */
        }

        cairo_surface_write_to_png(imgSurface, "output.png");
        cairo_destroy(imgContext);
        cairo_destroy(pdfContext);
        cairo_surface_destroy(imgSurface);
        cairo_surface_destroy(pdfSurface);

        cairo_debug_reset_static_data(); // Valgrind

        return 0;
}