Attachment 38019 Details for Bug 29710 – Sample program to reproduce the rendering problem

Sample program to reproduce the rendering problem

pixel.c (text/x-csrc), 1.94 KB, created by Ian Britten on 2010-08-20 10:13:37 UTC

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Creator: Ian Britten

Created: 2010-08-20 10:13:37 UTC

Size: 1.94 KB

patch

obsolete

>#include <cairo/cairo.h>
>#include <cairo/cairo.h>
>
>#include <math.h> // M_PI
>
>// This test demonstrates the drawing of a stray pixel.  (cairo 1.8.6)
>//
>// Build with:
>// gcc -g `pkg-config --cflags --libs cairo` pixel.c
>int main(int argc, char *argv[])
>{
>        const int pixWidth = 100;
>        const int pixHeight = 200;
>
>        cairo_surface_t *surface = cairo_image_surface_create(
>                CAIRO_FORMAT_ARGB32, pixWidth, pixHeight);
>        cairo_t *context = cairo_create(surface);
>
>        const double xMinUser = -10000.0;
>        const double yMinUser = -15000.0;
>        const double xMaxUser = 0.0;
>        const double yMaxUser = 5000.0;
>        const double userWidth = xMaxUser - xMinUser;
>        const double userHeight = yMaxUser - yMinUser;
>        const double scaleX = pixWidth / userWidth;
>        const double scaleY = pixHeight / userHeight;
>
>        // Rotate -45 degrees about the centre of the VP
>        const int vpCenX = pixWidth / 2;
>        const int vpCenY = pixHeight / 2;
>        const double txRotRad = -45 * M_PI / 180.0;
>        cairo_translate(context, vpCenX, vpCenY);
>        cairo_rotate(context, txRotRad);
>        cairo_translate(context, -vpCenX, -vpCenY);
>
>        // Scale the user window to fit, and flip it to Cartesian
>        cairo_translate(context, 0, pixHeight);
>        cairo_scale(context, scaleX, -scaleY);
>        cairo_translate(context, -xMinUser, -yMinUser);
>
>
>        // Draw a 2-point line, with a thickness
>        cairo_move_to(context, -10000, -10000);
>        cairo_line_to(context, 0, 0);
>        cairo_set_line_width(context, 2362.2047244094488); // From debugger
>        cairo_set_line_cap(context, CAIRO_LINE_CAP_ROUND);
>        cairo_stroke(context);
>
>        // Save out the contents and cleanup
>        cairo_surface_write_to_png(surface, "output.png");
>        cairo_destroy(context);
>        cairo_surface_destroy(surface);
>
>        cairo_debug_reset_static_data(); // Valgrind
>
>        return 0;
>}

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Attachments on bug 29710: 38019 | 38020 | 38021

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