Textures Example

// Writes an OMF file containing a projected texture and a mapped texture.

#include <assert.h>
#include <omf.h>
#include <stdio.h>
#include <stdlib.h>

static const double VERTICES[][3] = {
    { -1.0, -1.0, 0.0 },
    {  1.0, -1.0, 0.0 },
    {  1.0,  1.0, 0.0 },
    { -1.0,  1.0, 0.0 },
    // The tip vertex is duplicated here so it can have different texture coordinates for
    // each side face.
    {  0.0,  0.0, 1.0 },
    {  0.0,  0.0, 1.0 },
    {  0.0,  0.0, 1.0 },
    {  0.0,  0.0, 1.0 },
};

static const uint32_t TRIANGLES[][3] = {
    { 0, 1, 4 },
    { 1, 2, 5 },
    { 2, 3, 6 },
    { 3, 0, 7 },
    { 0, 2, 1 },
    { 0, 3, 2 },
};

static const float TEXCOORDS[][2] = {
    { 0.5, 0.0 },
    { 1.0, 0.5 },
    { 0.5, 1.0 },
    { 0.0, 0.5 },
    { 1.0, 0.0 },
    { 1.0, 1.0 },
    { 0.0, 1.0 },
    { 0.0, 0.0 },
};

static const char EXAMPLE_PNG[] = {
  0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0x00, 0x00, 0x00, 0x0d,
  0x49, 0x48, 0x44, 0x52, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x40,
  0x08, 0x02, 0x00, 0x00, 0x00, 0x25, 0x0b, 0xe6, 0x89, 0x00, 0x00, 0x00,
  0x09, 0x70, 0x48, 0x59, 0x73, 0x00, 0x00, 0x02, 0x80, 0x00, 0x00, 0x02,
  0x80, 0x01, 0x5b, 0x4d, 0x5f, 0x70, 0x00, 0x00, 0x00, 0x19, 0x74, 0x45,
  0x58, 0x74, 0x53, 0x6f, 0x66, 0x74, 0x77, 0x61, 0x72, 0x65, 0x00, 0x77,
  0x77, 0x77, 0x2e, 0x69, 0x6e, 0x6b, 0x73, 0x63, 0x61, 0x70, 0x65, 0x2e,
  0x6f, 0x72, 0x67, 0x9b, 0xee, 0x3c, 0x1a, 0x00, 0x00, 0x01, 0x9a, 0x49,
  0x44, 0x41, 0x54, 0x68, 0xde, 0xd5, 0xda, 0x3b, 0x72, 0xc3, 0x30, 0x0c,
  0x04, 0x50, 0x71, 0x6f, 0x1b, 0x17, 0xb9, 0x41, 0xba, 0x9c, 0x21, 0xb7,
  0xf4, 0xcc, 0xde, 0x40, 0x2e, 0x92, 0xc9, 0x78, 0xfc, 0x91, 0xf0, 0x25,
  0x01, 0x55, 0x2e, 0x48, 0x61, 0x5f, 0x21, 0x4b, 0x24, 0x31, 0xb6, 0x9f,
  0x7d, 0x4b, 0xbd, 0x3e, 0xbe, 0x53, 0x6f, 0x8f, 0xd4, 0xbb, 0xef, 0x97,
  0xb1, 0x8f, 0xaf, 0xae, 0x80, 0xfd, 0x32, 0xfe, 0x7e, 0x64, 0x1a, 0x90,
  0x9d, 0x3e, 0xdb, 0x80, 0x09, 0xe9, 0x53, 0x0d, 0x98, 0x93, 0x3e, 0xcf,
  0x80, 0x69, 0xe9, 0x93, 0x0c, 0x98, 0x99, 0x3e, 0xc3, 0x80, 0xc9, 0xe9,
  0xc3, 0x0d, 0x98, 0x9f, 0x3e, 0xd6, 0x80, 0x25, 0xe9, 0x03, 0x0d, 0x58,
  0x95, 0x3e, 0xca, 0x80, 0x85, 0xe9, 0x43, 0x0c, 0x58, 0x9b, 0xde, 0x6f,
  0xc0, 0xf2, 0xf4, 0x4e, 0x03, 0x2a, 0xa4, 0xf7, 0x18, 0x50, 0x24, 0xbd,
  0xd9, 0x80, 0x3a, 0xe9, 0x6d, 0x06, 0x94, 0x4a, 0x6f, 0x30, 0xa0, 0x5a,
  0x7a, 0xad, 0x01, 0x05, 0xd3, 0xab, 0x0c, 0xa8, 0x99, 0x5e, 0x6e, 0x40,
  0xd9, 0xf4, 0x42, 0x03, 0x2a, 0xa7, 0x97, 0x18, 0x50, 0x3c, 0xfd, 0xa9,
  0x01, 0xf5, 0xd3, 0x1f, 0x1b, 0xd0, 0x22, 0xfd, 0x81, 0x01, 0x5d, 0xd2,
  0xbf, 0x33, 0xa0, 0x51, 0xfa, 0x97, 0x06, 0xf4, 0x4a, 0xff, 0x6c, 0x40,
  0xbb, 0xf4, 0x0f, 0x06, 0x74, 0x4c, 0x7f, 0x6f, 0x18, 0xfb, 0xd6, 0xfb,
  0xc2, 0xf6, 0x79, 0x6d, 0x1c, 0x9f, 0xbf, 0xcf, 0x40, 0x53, 0x03, 0xef,
  0xff, 0x85, 0xda, 0x19, 0xf8, 0xfc, 0x1e, 0x68, 0x64, 0xe0, 0xbb, 0x37,
  0x71, 0x0b, 0x03, 0x8f, 0xbf, 0x85, 0x8a, 0x1b, 0x28, 0xf9, 0x1a, 0x2d,
  0x6b, 0xa0, 0x7c, 0x3d, 0x50, 0xd0, 0x40, 0xed, 0x8a, 0xac, 0x94, 0x81,
  0xb6, 0x35, 0x71, 0x11, 0x03, 0x3d, 0xbb, 0x12, 0xcb, 0x0d, 0xf4, 0xed,
  0x4a, 0x2c, 0x36, 0xf0, 0x7c, 0x88, 0x6c, 0x67, 0x6e, 0x89, 0x81, 0xa2,
  0x51, 0xe2, 0xbd, 0xd1, 0xc9, 0x06, 0x4a, 0x07, 0x6a, 0x76, 0xa7, 0xa7,
  0x19, 0xa8, 0x18, 0xab, 0x3c, 0x1f, 0x98, 0x60, 0xa0, 0x6e, 0xb8, 0xfe,
  0x84, 0x26, 0xd5, 0x40, 0xf5, 0x0c, 0xd3, 0x19, 0x59, 0x92, 0x81, 0x96,
  0x49, 0xd6, 0x53, 0xca, 0x70, 0x03, 0x8d, 0xf3, 0x1c, 0xe7, 0xc4, 0x81,
  0x06, 0xda, 0xa7, 0xfa, 0x4e, 0xea, 0x43, 0x0c, 0x74, 0xcd, 0x76, 0xf7,
  0x4a, 0x38, 0x0d, 0xf4, 0xd6, 0x8f, 0xe8, 0x56, 0x31, 0x1b, 0x18, 0x50,
  0x3c, 0xa8, 0x5f, 0xc8, 0x60, 0x60, 0x4c, 0xe5, 0xb8, 0x8e, 0x2d, 0x95,
  0x81, 0x61, 0x65, 0x43, 0x7b, 0xe6, 0x84, 0x06, 0x46, 0xd6, 0x8c, 0xee,
  0x5a, 0x3c, 0x35, 0x30, 0xb8, 0x60, 0x42, 0xdf, 0xe8, 0x81, 0x81, 0xf1,
  0xd5, 0x72, 0x3a, 0x77, 0x5f, 0x1a, 0x98, 0x52, 0x2a, 0xad, 0x77, 0xfa,
  0xc1, 0xc0, 0xac, 0x3a, 0x99, 0xdd, 0xeb, 0xff, 0x06, 0x26, 0x16, 0xb9,
  0x01, 0x89, 0x4f, 0xa5, 0x0e, 0xa3, 0x13, 0xdc, 0x24, 0x00, 0x00, 0x00,
  0x00, 0x49, 0x45, 0x4e, 0x44, 0xae, 0x42, 0x60, 0x82
};
static const size_t EXAMPLE_PNG_LEN = 525;

static bool write(const char *path) {
    OmfError *error;
    OmfWriter *writer;
    OmfProject project;
    OmfElement element;
    OmfSurface surface;
    OmfAttribute attribute;
    OmfMappedTexture mapped;
    OmfProjectedTexture projected;
    OmfHandle *proj_handle, *surf_handle;
    const OmfArray *image;

    // Open the file and create a project.
    writer = omf_writer_open(path);
    project = omf_project_init("textures.omf");
    proj_handle = omf_writer_project(writer, &project);

    // Create a pyramid surface element and keep that handle too.
    surface = omf_surface_init(
        omf_writer_array_vertices64(writer, VERTICES, 8),
        omf_writer_array_triangles(writer, TRIANGLES, 5)
    );
    element = omf_element_init("Pyramid");
    element.surface = &surface;
    surf_handle = omf_writer_element(writer, proj_handle, &element);

    // Add the image that both texture types will use.
    image = omf_writer_image_bytes(writer, EXAMPLE_PNG, EXAMPLE_PNG_LEN);

    // Add mapped texture attribute.
    mapped = omf_mapped_texture_init(image, omf_writer_array_texcoords32(writer, TEXCOORDS, 8));
    attribute = omf_attribute_init("Mapped", OMF_LOCATION_VERTICES);
    attribute.mapped_texture_data = &mapped;
    omf_writer_attribute(writer, surf_handle, &attribute);

    // Add projected texture attribute.
    projected = omf_projected_texture_init(image);
    projected.orient.origin[0] = -1.0;
    projected.orient.origin[1] = -1.0;
    projected.orient.origin[2] = 0.0;
    projected.orient.u[0] = 1.0;
    projected.orient.u[1] = 0.0;
    projected.orient.u[2] = 0.0;
    projected.orient.v[0] = 0.0;
    projected.orient.v[1] = 0.0;
    projected.orient.v[2] = 1.0;
    projected.width = 2.0;
    projected.height = 2.0;
    attribute = omf_attribute_init("Projected", OMF_LOCATION_PROJECTED);
    attribute.projected_texture_data = &projected;
    omf_writer_attribute(writer, surf_handle, &attribute);

    // Finish writing and close the file.
    omf_writer_finish(writer, NULL);

    // Check for errors.
    if ((error = omf_error()) != NULL) {
        fprintf(stderr, "[write failed] %s (%d)\n", error->message, error->code);
        omf_error_free(error);
        return false;
    }
    return true;
}

static bool read(const char *path) {
    OmfReader *reader;
    const OmfProject *project;
    OmfError *error;
    OmfImageData *image_data;

    // Open the file and read the project.
    reader = omf_reader_open(path);
    project = omf_reader_project(reader, NULL);
    if (!project) {
        error = omf_error();
        fprintf(stderr, "[read failed] %s (%d)\n", error->message, error->code);
        omf_error_free(error);
        return false;
    }
    printf("name: %s\n", project->name);

    // Read the texture image back.
    image_data = omf_reader_image(
        reader, project->elements[0].attributes[0].mapped_texture_data->image);
    assert(image_data);
    assert(image_data->mode == OMF_IMAGE_MODE_RGB);
    assert(image_data->width == 64);
    assert(image_data->height == 64);
    // This now contains the pixels in RGB order with no padding.
    assert(image_data->uint8);
    // Free the image data.
    omf_image_data_free(image_data);

    // Close the reader only once we're done with `project`.
    omf_reader_close(reader);

    // Check for errors.
    if ((error = omf_error()) != NULL) {
        fprintf(stderr, "[read failed] %s (%d)\n", error->message, error->code);
        omf_error_free(error);
        return false;
    }
    return true;
}

int main() {
    if (!write("textures.omf")) return 1;
    if (!read("textures.omf")) return 1;
    return 0;
}