/* * Example program for the Allegro library, by Bertrand Coconnier. * * This program demonstrates how to use Z-buffered polygons and * floating point 3D math routines. It also provides a simple * way to compute fps (frames per second) using a timer. After * selecting a screen resolution through the standard GUI dialog, * the example shows two 3D cubes rotating and intersecting each * other. Rather than having full polygons incorrectly overlap * other polgons due to per-polygon sorting, each pixel is drawn * at the correct depth. */ #include typedef struct FACE { int v1, v2, v3, v4; } FACE; V3D_f cube1[] = { { -32., -32., -32., 0., 0., 72}, { -32., 32., -32., 0., 0., 80}, { 32., 32., -32., 0., 0., 95}, { 32., -32., -32., 0., 0., 88}, { -32., -32., 32., 0., 0., 72}, { -32., 32., 32., 0., 0., 80}, { 32., 32., 32., 0., 0., 95}, { 32., -32., 32., 0., 0., 88} }; V3D_f cube2[] = { { -32., -32., -32., 0., 0., 104}, { -32., 32., -32., 0., 0., 112}, { 32., 32., -32., 0., 0., 127}, { 32., -32., -32., 0., 0., 120}, { -32., -32., 32., 0., 0., 104}, { -32., 32., 32., 0., 0., 112}, { 32., 32., 32., 0., 0., 127}, { 32., -32., 32., 0., 0., 120} }; FACE faces[] = { { 2, 1, 0, 3 }, { 4, 5, 6, 7 }, { 0, 1, 5, 4 }, { 2, 3, 7, 6 }, { 4, 7, 3, 0 }, { 1, 2, 6, 5 } }; volatile int t; /* timer interrupt handler */ void tick(void) { t++; } END_OF_FUNCTION(tick) /* update cube positions */ void anim_cube(MATRIX_f* matrix1, MATRIX_f* matrix2, V3D_f x1[], V3D_f x2[]) { int i; for (i=0; i<8; i++) { apply_matrix_f(matrix1, cube1[i].x, cube1[i].y, cube1[i].z, &(x1[i].x), &(x1[i].y), &(x1[i].z)); apply_matrix_f(matrix2, cube2[i].x, cube2[i].y, cube2[i].z, &(x2[i].x), &(x2[i].y), &(x2[i].z)); persp_project_f(x1[i].x, x1[i].y, x1[i].z, &(x1[i].x), &(x1[i].y)); persp_project_f(x2[i].x, x2[i].y, x2[i].z, &(x2[i].x), &(x2[i].y)); } } /* cull backfaces and draw cubes */ void draw_cube(BITMAP* buffer, V3D_f x1[], V3D_f x2[]) { int i; for (i=0; i<6; i++) { V3D_f vtx1, vtx2, vtx3, vtx4; vtx1 = x1[faces[i].v1]; vtx2 = x1[faces[i].v2]; vtx3 = x1[faces[i].v3]; vtx4 = x1[faces[i].v4]; if (polygon_z_normal_f(&vtx1, &vtx2, &vtx3) > 0) quad3d_f(buffer, POLYTYPE_GCOL | POLYTYPE_ZBUF, NULL, &vtx1, &vtx2, &vtx3, &vtx4); vtx1 = x2[faces[i].v1]; vtx2 = x2[faces[i].v2]; vtx3 = x2[faces[i].v3]; vtx4 = x2[faces[i].v4]; if (polygon_z_normal_f(&vtx1, &vtx2, &vtx3) > 0) quad3d_f(buffer, POLYTYPE_GCOL | POLYTYPE_ZBUF, NULL, &vtx1, &vtx2, &vtx3, &vtx4); } } int main(void) { ZBUFFER *zbuf; BITMAP *buffer; PALETTE pal; MATRIX_f matrix1, matrix2; V3D_f x1[8], x2[8]; int i; int c = GFX_AUTODETECT; int w, h, bpp; int frame = 0; float fps = 0.; float rx1, ry1, rz1; /* cube #1 rotations */ float drx1, dry1, drz1; /* cube #1 rotation speed */ float rx2, ry2, rz2; /* cube #2 rotations */ float drx2, dry2, drz2; /* cube #1 rotation speed */ float tx = 16.; /* x shift between cubes */ float tz1 = 100.; /* cube #1 z coordinate */ float tz2 = 105.; /* cube #2 z coordinate */ if (allegro_init() != 0) return 1; install_keyboard(); install_mouse(); install_timer(); LOCK_VARIABLE(t); LOCK_FUNCTION(tick); install_int(tick, 10); /* color 0 = black */ pal[0].r = pal[0].g = pal[0].b = 0; /* color 1 = red */ pal[1].r = 255; pal[1].g = pal[1].b = 0; /* copy the desktop palette */ for (i=1; i<64; i++) pal[i] = desktop_palette[i]; /* make a blue gradient */ for (i=64; i<96; i++) { pal[i].b = (i-64)*2; pal[i].g = pal[i].r = 0; } /* make a green gradient */ for (i=96; i<128; i++) { pal[i].g = (i-96)*2; pal[i].r = pal[i].b = 0; } /* set the graphics mode */ if (set_gfx_mode(GFX_SAFE, 320, 200, 0, 0) != 0) { set_gfx_mode(GFX_TEXT, 0, 0, 0, 0); allegro_message("Unable to set any graphic mode\n%s\n", allegro_error); return 1; } set_palette(desktop_palette); w = SCREEN_W; h = SCREEN_H; bpp = bitmap_color_depth(screen); if (!gfx_mode_select_ex(&c, &w, &h, &bpp)) { allegro_exit(); return 1; } set_color_depth(bpp); if (set_gfx_mode(c, w, h, 0, 0) != 0) { set_gfx_mode(GFX_TEXT, 0, 0, 0, 0); allegro_message("Error setting graphics mode\n%s\n", allegro_error); return 1; } set_palette(pal); /* double buffer the animation and create the Z-buffer */ buffer = create_bitmap(SCREEN_W, SCREEN_H); zbuf = create_zbuffer(buffer); set_zbuffer(zbuf); /* set up the viewport for the perspective projection */ set_projection_viewport(0, 0, SCREEN_W, SCREEN_H); /* compute rotations and speed rotation */ rx1 = ry1 = rz1 = 0.; rx2 = ry2 = rz2 = 0.; drx1 = ((AL_RAND() & 31) - 16) / 4.; dry1 = ((AL_RAND() & 31) - 16) / 4.; drz1 = ((AL_RAND() & 31) - 16) / 4.; drx2 = ((AL_RAND() & 31) - 16) / 4.; dry2 = ((AL_RAND() & 31) - 16) / 4.; drz2 = ((AL_RAND() & 31) - 16) / 4.; /* set the transformation matrices */ get_transformation_matrix_f(&matrix1, 1., rx1, ry1, rz1, tx, 0., tz1); get_transformation_matrix_f(&matrix2, 1., rx2, ry2, rz2, -tx, 0., tz2); /* set colors */ for (i=0; i<8; i++) { x1[i].c = palette_color[cube1[i].c]; x2[i].c = palette_color[cube2[i].c]; } /* main loop */ while(1) { clear_bitmap(buffer); clear_zbuffer(zbuf, 0.); anim_cube(&matrix1, &matrix2, x1, x2); draw_cube(buffer, x1, x2); /* update transformation matrices */ rx1 += drx1; ry1 += dry1; rz1 += drz1; rx2 += drx2; ry2 += dry2; rz2 += drz2; get_transformation_matrix_f(&matrix1, 1., rx1, ry1, rz1, tx, 0., tz1); get_transformation_matrix_f(&matrix2, 1., rx2, ry2, rz2, -tx, 0., tz2); textprintf_ex(buffer, font, 10, 1, palette_color[1], 0, "Z-buffered polygons (%.1f fps)", fps); vsync(); blit(buffer, screen, 0, 0, 0, 0, SCREEN_W, SCREEN_H); frame++; if (t > 100) { fps = (100. * frame) / t; t = 0; frame = 0; } if (keypressed()){ if ((readkey() & 0xFF) == 27) break; } } destroy_bitmap(buffer); destroy_zbuffer(zbuf); return 0; } END_OF_MAIN()